No ground at main panel?


  #1  
Old 03-22-01, 02:10 AM
Nagoy
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I've learnt a lot from posts here, but now I'm confused again: As I was thinking about adding an extra couple of circuits to my garage, I noticed my main panel does not appear to be grounded...!

The panel brand is Bryant (probably original to the house, which is early 60's), its inside my attached garage, theres a neutral bar but no ground bar. The diagram indicates a position on that bar that would have the ground wire attached "when required". The diagram also indicates a "bond when required" point on the bar. There are as many white wires attached to the neutral bar as there are entering the panel, so that accounts for all the neutrals, but there are no other wires. So, no ground?

I do have a couple of circuits with grounded receptacles, but I believe these are armored cable runs, the others being cloth covered cable. My guess is that these armored cables are probably bonded to the cold water pipe somewhere to provide ground. Since these cables are attached to the panel, the panel casing is probably grounded.

- Is there any way of verifying this?

I'm simply wondering what to do! This, and a lot of the questions I've had before, have pointed at replacing the panel with a modern one.

- If I have this done, and a grounding rod connected, are the 'mechanically' grounded circuits safe, and would this solve my problem?

Thanks!
 
  #2  
Old 03-22-01, 09:31 AM
J
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Location: Fayetteville, NY, USA
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First, older services often have a #10 copper ground wire run inside of a small diameter armored cable to the water main, near its entrance to the building. You can go to your water meter area and see if you have such a wire clamped on the water pipe and trace it back to the panel.

The NEC now requires a ground rod. Existing systems are exempt, but if you upgrade your service it will be required. A minimum #6AWG copper ground conductor will be run from the rod to your main panel, and from there also to your water main. To get grounded branch circuits to the various areas of your house you will probably have to rip out walls because you will need to run new cable that contains a ground wire.

As far as grounding/bonding, if the main breaker (or fuse) in your Bryant panel is the first disconnect on your side of the meter, this is technically called your "service equipment". Here and only here the neutral bus is "bonded" to the steel panel enclosure, and all grounds and neutrals go together on the same bus bar. "When required" refers to if that panel is used as a sub-panel if installed downstream from your main panel ("service equipment"), which seems like it's not your situation. Then you cannot bond your neutral bus to tthe enclosure, and must have separated grounds & neutrals.

Second, it is possible that you have a two wire system, meaning ungrounded. For the couple of "grounded outlets" you say you have, do you know if there is a ground wire in the wall box which is connected to the grounding screw on the receptacle itself? I suspect not. Many times, though, armored cable or conduit was run to metal wall boxes, forming a ground path. Not a great ground, but it generally works, and is still approved if cdone correctly. Anyway, I suspect somebody prior to you has replaced 2-prong receptacles with 3-prong models without installing a ground. This is illegal. The only approved way to do this is to replace a 2-prong with a GFCI 3-prong receptacle, and then you must attach the little sticker that comes with them, which states "No equipment ground", to the wallplate so users know they are not grounded.

Replacing you older panel is a bit complicated if you lack significant experience with both the National Electrical Code (NEC) and with electrical installation work. In many localities you don't have to be a licensed electrician to do your own electrical work, but you are required to obtain a permit and have a final electrical inspection done and pass. Aside from this being the law, your insurance company can give you trouble if there's an electrical fire if you do not have a certificate of compliance on electrical work you have done.

If you hire an electrician s/he will deal with the permit, inspection, utility work order and that sort of thing. This will be included in his/her bill. For about $900 you can have your service upgraded to the minimum allowed by the NEC of 100 amps. I would personally recommend a minimum of 150 amps, unless you have a lot of major electrical appliances such as electric heat, hot water, range, dryer, etc. Then I'd generally recommend minimum 200 amps, but the official number is based on calculations found in the NEC, which includes a number of parameters including the square footage of your home. An electrician can do this for you for a little extra.

But if you feel this upgrade is something you can do, feel free to ask for more info here in the forum. I'm not an electrician but have extensive experience in both field work and design, and I upgraded my service last year from a 4-fuse, 60 amp panel to a 30-space 150 amp breaker panel, and passed inspection no problem. It was a lot of work, though! I'd be glad to offer any advice.

Hope that helps.

Juice

[Edited by JuiceHead on 03-22-01 at 12:38]
 
twinnii voted this post useful.
  #3  
Old 03-22-01, 01:14 PM
Nagoy
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>To get grounded branch circuits to the various areas of your house you will probably have to rip out walls because you will need to run new cable that contains a ground wire.

Is this required for existing circuits, or do you just mean for new grounded ones?

>Second, it is possible that you have a two wire system, meaning ungrounded.

Ahhh! Theres a label (actually looks newer than the box, but couldn't say for sure) that mentions soemthing along those lines. I didn't quite understand it though, as it said 'neutral is not used'...I was expecting it to say ground is not used. I can repeat it here word-for-word tonight.

>For the couple of "grounded outlets" you say you have, do you know if there is a ground wire in the wall box which is connected to the grounding screw on the receptacle itself? I suspect not. Many times, though, armored cable or conduit was run to metal wall boxes, forming a ground path. Not a great ground, but it generally works, and is still approved if cdone correctly.

No ground wire.

>Anyway, I suspect somebody prior to you has replaced 2-prong receptacles with 3-prong models without installing a ground. This is illegal. The only approved way to do this is to replace a 2-prong with a GFCI 3-prong receptacle, and then you must attach the little sticker that comes with them, which states "No equipment ground", to the wallplate so users know they are not grounded.

The 3-prong receptacles are the ones above, grounded via armor. I discovered the no-ground wire while replacing them with gfci's in the kitchen and bathrooms. The rest of the house is still 2-prong.

>Replacing you older panel is a bit complicated ... <snip> ... I would personally recommend a minimum of 150 amps

That was one of my first posts to this forum (and it was FULL of questions!). I decided it was too complicated at the time - now I'm more confident. Timing was the main issue, with power off, inspections due, etc. Now I think I could do it, 'with a little help from my friends' and a good reference, maybe installing the new panel right next to the old one before actually hooking it up to power - that way I could have it inspected with less of critical timing issues...?

>But if you feel this upgrade is something you can do, feel free to ask for more info here in the forum. I'm not an electrician but have extensive experience in both field work and design, and I upgraded my service last year from a 4-fuse, 60 amp panel to a 30-space 150 amp breaker panel, and passed inspection no problem. It was a lot of work, though! I'd be glad to offer any advice.

I hope so! The main reason for replacing would be to fix the ground problem and get more spaces (currently only 12). Can you replace with a 200A-rated panel without changing the actual service delivered (ie for future proofing)? A 200A panel can handle up to 200A, it doesn't draw that amount of current? The main disconnect is outside by the meter, its a 100A breaker, so the amergae would be limited for now before it got to the panel.

Incidentally (hopefully wg will read this and comment as an inspector), if I explain the current situation to the electrical inspector, and what I propose to do, will they tell me if I've missed anything, or will they just fail the inspection! Maybe it depends on the inspector....how about I fly wg out to Ca, I'm sure it'd work out cheaper than an electrician

Thanks. Perhaps if I devise an upgrade plan, I could post it somewhere and get some opinon.
 
  #4  
Old 03-22-01, 06:08 PM
Wgoodrich
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I understand you are from california. YOu might want to check for local ordinances that may affect your wiring design due to those local rules in local design requirments.

In my opinion Juice gave you a pretty good picture on the subject however a few more ideas may be added to help.

First off it worries me some on the sign saying neutrals not used. Is this on one certain circuit or representing hte whole house?

You should be allowed to do this rewire on a partial basis if you wish. Check before hand with your local Inspector.

As for DIYing it depends on the laws in your locality whether you must be licensed to do this job.

Now you asked what to expect from your Inspector. I have seen all kinds. Some are power happy, some knows it all,some think they know it all, some are full of free help in an attempt to educate, some are cockey and of no help.

Best bet is to go talk to the Inspector and ask a bunch of questions of your concerns and read the person as to what he is like.

Juice did you pretty good.

Hope we helped so far

Wg
 
  #5  
Old 03-22-01, 09:14 PM
Nagoy
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>In my opinion Juice gave you a pretty good picture on the subject however a few more ideas may be added to help.

Speaking of pictures, thought the links below might shed some light...note that it doesn't work right (at least it didn't for me) - you seem to have to copy the url, go to another page, then paste the address back in and hit retrun, else you get a 'page unavailable' msg.

>First off it worries me some on the sign saying neutrals not used. Is this on one certain circuit or representing hte whole house?

Its a label on the door:
http://www.geocities.com/mark_britboy/img/label.gif

Incidentally, the wires entering bottom left were the ones directly connected to the main lugs feeding my shed fuse box, and are disconnected as recommended.

This is the whole panel:
http://www.geocities.com/mark_britboy/img/panel.gif

Finally, the circuit diagram, just cos I was in the mood:
http://www.geocities.com/mark_britboy/img/diagram.gif

>You should be allowed to do this rewire on a partial basis if you wish.

Not sure I understand what you mean by a 'partial basis'. Do you mean adding the ground and being able to leave the existing circuits as they are?


>Hope we helped so far

Yes, as always. Hope the pics helped.
 
  #6  
Old 03-23-01, 10:15 AM
J
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Location: Fayetteville, NY, USA
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1) You are not required to run grounds to your existing ungrounded circuits. You would do this if you wanted to create a new grounded circuit or wanted to provide grounding to an existing circuit. One example has come up in the forum several times - where the person seeking advice wanted to install a TVSS (Transient Voltage Surge Supressor) for their new computer. These devices don't work unless plugged into a grounded receptacle.

2) I was unable to view the pictures. I personally have not heard of a dwelling electrical service which does not use a neutral. It's just a guess, but I think you have two 110 volt hot legs and one neutral leg to provide a typical 220 volt system, but have no ground.

3) You say that the armored cable provides a ground. To test if this is the case, shove one probe of a volt meter into the hot slot and touch the box with the other probe. If you see approx. 110 volts, the box is grounded. If not it's not.

4) When I upgraded my service I increased the amperage of the panel from 60 to 150 amps. This required that I increase the size of my "service entrance cable". That's the cable that goes from the utility's aerial down to the meter. You own this wire. (If you leave the 100 amp disconnect in place you do not need to increase the entrance cable size, since even if you installed a 10,000 amp panel it would be restricted by the 100 amp disconnect.) . I installed my new weatherhead next to the old one, and installed the new cable next to the old one, ran the cable from the new weatherhead to a new meter socket (most utilities require you to provide this, and they provide the glass meter only), and from the meter socket to the area where the existing panel was. I installed my new panel next to the old one so switching all the individual circuits would be easy and convenient.

I also installed two ground rods and the grounding conductor, connected these to the new panel and to the water system.

Now here's the neat trick. With the (very helpful) inspector's advice I pulled out the main fuse block and installed jumpers from the sub-feed lugs in the old panel to the main lugs of the new panel, thus feeding the old from the new. Now, with brief power interruptions I transferred a few circuits at a time over to the new panel. Each time, when I turned the juice back on, all the existing circuits worked, powered either from where they were connected originally, or from the new panel where I moved them.

When the utility company came to do the cut-off/cut-on all that was left for me to do was yank out the jumpers and shove the new cable conductors into their respective lugs in the new panel while the utility guy was up top switching their aerial wires from my old wires over to the new wires. We were each done in about 30 minutes and they were able to throw the juice back on.

During the project my inspector (The New York Board of Fire Underwriters is the AHJ in my area) was very helpful, and although he is in the field doing inspections most of the day, he always returned my calls and took his time to answer my questions. When he showed up for the actual inspection he was done in about 20 minutes.

If you're a good planner this can be done at your liesure and with a minimum of down time. I was deermined that the utility and the inspector would come just once, and that is how I approached every task involved in this project. It was sort of hard at times, but it paid off. I have a valid certificate of compliance, and my insurance agent is a very happy man. (My old panel was a complete mess from years of the previous owner's additions and modifications. And the guy was clearly electrically challenged!)

If you want a bunch of specifics, I can probably tell you every nut & bolt that goes into the job, as well as many tips on installation practices & procedures. Feel free to e-mail me on this. It could involve a lot of tiny details that wouldn't be so much of general interest to forum visitors. Or write in here and get multiple opinions if you wish. Whatever works for you, I'm just glad to help.

Good luck.

Juice
 
  #7  
Old 03-23-01, 10:47 AM
Nagoy
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Thanks for the comments

>1) You are not required to run grounds to your existing ungrounded circuits. You would do this if you wanted to create a new grounded circuit or wanted to provide grounding to an existing circuit....

Ok - actually I meant what about the existing 'mechanically grounded' circuits. Isn't there a rule about only one source of ground?

>2) I was unable to view the pictures. I personally have not heard of a dwelling electrical service which does not use a neutral. It's just a guess, but I think you have two 110 volt hot legs and one neutral leg to provide a typical 220 volt system, but have no ground.

I couldn't view them straight from this page from work either. You have to copy the url, go to another page (eg click 'Home'), then paste the url back and hit return. In any case the label reads:

"ADDITIONAL RATING 240V., 1 PH., 2 WIRE
For this system, neutral is not used and only breakers
rated at 240V. AC are to be used.

and your suggestion sounds quite likely.

>3) You say that the armored cable provides a ground. To test if this is the case, shove one probe of a volt meter into the hot slot and touch the box with the other probe. If you see approx. 110 volts, the box is grounded. If not it's not.

Problem is, I don't know which armored cable is providing ground (if only one is), since they are both attached to the panel. But the receptacles on the grounded circuits lost ground when out of the metal box, so thats what I concluded.

>4) .... (If you leave the 100 amp disconnect in place you do not need to increase the entrance cable size, since even if you installed a 10,000 amp panel it would be restricted by the 100 amp disconnect.)...

This is what I'm thinking. I don't have any need at the moment to increase actual delivered current, but I only want to replace the panel once!

>If you want a bunch of specifics, I can probably tell you every nut & bolt that goes into the job, as well as many tips on installation practices & procedures. Feel free to e-mail me on this. It could involve a lot of tiny details that wouldn't be so much of general interest to forum visitors. Or write in here and get multiple opinions if you wish. Whatever works for you, I'm just glad to help.

Thanks again - if you have any of this already documented in a format you can easily email, that would be ridiculously helpful! If it would involve some effort, then don't go to too much trouble for now. I'd hate to have you spend a lot of time preparing something, and I end up hiring a pro...!

Mark
 
  #8  
Old 03-23-01, 11:42 AM
Wgoodrich
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Mark email me and I will send you an attachment with a pass out called wiring a service that I wrote re the 99 NEC. Be aware that some changes may be required to meet your local jurisdictional rules but should give you a shot at what you need to do. One thing that I want to confirm though is that you are in the United States. Your no neutral panel still bothers me some, sounds like a panel designed for a country that uses no neutrals but have 200 volt general use receptacles.

Please confirm that you can open msoffice 2000 word, if not then I will have to send it to you in email format. Pretty big email, hotmail would not accept that size email.

wgoodrich@tds.net

Good Luck

Wg
 
  #9  
Old 03-23-01, 01:26 PM
resqcapt19
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Wg,
Look at what Mark said is on the panel label in his last post. It appears to me that this is just an additional listing that allows this panel to be used on a 2 wire 240 volt system as well as the standard 3 wire 120/240 volt system.
Don(resqcapt19)
 
  #10  
Old 03-23-01, 02:20 PM
Nagoy
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Just had a thought:

I'm English and living in CA. I'll email Wg in a moment. The previous occupants were also English, they'd lived in the house for a long time (25-30 yrs?). In the UK, if you didn't know, the electrical system is 240V (not 120 + 120), with wires we call positive, negative and ground. I wonder if this had something to do with it. Strange to have this on there, though....

 
  #11  
Old 03-23-01, 02:42 PM
Wgoodrich
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resqcapt19, I think you are right, just being a bit on the cautious side mainly because he mentioned it. I suspect that this panel comes in as a service rated panel with a grounding service jumper to be installed as the main service rated panel. Yet an extra grounding bar can be added to the box and leave the neutral bar to be floating for a sub panel installation. Just wanted to be caustious on this application. If he will email me I will send him the wiring a service pass out, let him read that then come back in with his bank of questions. May spead understanding that way.

Wg
 
  #12  
Old 03-23-01, 02:54 PM
Nagoy
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If you can manage to get the links above to work (with the copy url, go to another page, then paste url back method....sorry, don't know why it doesn't work straight off), theres two pics of the panels wiring diagram.


Added:
Wg: email received and openable - thx.
 
  #13  
Old 03-23-01, 03:48 PM
Wgoodrich
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You might try contacting the moderator of this forum. He may be able to post your pictures on a URL for us.

Wg
 
  #14  
Old 03-24-01, 10:07 AM
J
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Location: Fayetteville, NY, USA
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1) What do you mean about "Mechanically Grounded"? And yes, I think all grounds in a single electrical system should be connected to one common grounding source. Some would disagree, for instance where you have a detached garage (or other detached building) and do not send an equipment grounding conductor with your hots & neutral, but instead have a separately derived grounding system with it's own ground rod for the garage. There is much disagreement whether this is correct, but I and a few others feel that your detached building is just fine sharing a common ground with the ground at your main panel.

3) Older wiring practices and receptacle construction relied on the mechanical connection of the receptacle to the metal wall box. Modern receptacles have a ground terminal, and should be connected to the box with a #12 piece of bare copper wire, using only a self-tapping screw colored green and not a sheet metal screw. That's why you lost ground as soon as removed from the box.

4) I like what you're doing with the main disconnect. This being between your meter and your present main panel is good for you, because you don't need to involve the utility, and can kill the conductors to the main panel and replace it working in total safety. Of course you will test all conductors with a volt meter just to be sure, as well as first testing the volt meter on something live to make sure IT works. I absolutely agree with your doing this. You're obtaining more spaces for additional breakers (your stated motive), and having to buy a higher amperage panel to get more spaces, and having the ability to upgrade the main service at a later time should your electrical loads increase remains an option. Looks like you hold all the cards, a no lose situation. Because of the distance from my new meter location to the old panel location where I hung my new panel, I had to provide a main switch since my local inspector's interpretation of the vague NEC language in its location requirement was to have it installed "within 5-7 feet". Other areas interpret it different. Anyway, now I'm glad I have it. I can kill the breaker panel without contacting the utility when I have anything major to tackle electrically.

5) As far as providing you detailed info on hardware, wiring practices, tricks, etc. I will be glad to do this anytime you request. Shopping for all this stuff can be very confusing and seem complicated. I know the "good stuff" from the junk, and can pretty much steer you toward a quality installation. Anyway, when you get close to this just give a holler. No trouble at all.

6) You're English, huh? I'm an all American, bullet-headed Saxon Mother's son. (All the children sing...) So anyway, I thought you used the terminology "positive, negative, and Earth". We generally call your negative "Neutral, which I'm sure you know, but on 120 volt branch circuits this becomes confusing to many folks. For a 3-wire 240 volt system, (we usually call it 220 volts) you do of course have two 120 volt hot legs and a true neutral. But on 120 volt, 2-wire circuits you are actually supposed to call it "the grounded conductor", since it is not technically neutral. But most folks you talk to will still call it "neutral", and every body pretty much knows exactly what you mean. It's just electrical junkies that give a hoot about calling it by its technical name.

Juice
 
  #15  
Old 03-25-01, 03:13 AM
Nagoy
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Juice,

>1)What do you mean about "Mechanically Grounded"?

>3)Older wiring practices and receptacle construction
>relied on the mechanical connection of the receptacle to
>the metal wall box.

Thats what I meant by mechanically ground - the armored cable and/or conduit back to the panel, and to any other armored cables coming off it - as opposed to a ground wire. Am I making up my own terminology already...?!

>4) I like what you're doing with the main disconnect. This
>being between your meter and your present main panel is
>good for you, because you don't need to involve the
>utility, and can kill the conductors to the main panel and
>replace it working in total safety.

Total safety, yes....can I quote you on that later?!

>5) As far as providing you detailed info on hardware,
>wiring practices, tricks, etc. I will be glad to do this
>anytime you request. Shopping for all this stuff can be
>very confusing and seem complicated. I know the "good
>stuff" from the junk, and can pretty much steer you toward
>a quality installation. Anyway, when you get close to this
>just give a holler. No trouble at all.

I think I dropped you an email (through this system). Don't know if you got it. What I'm unsure about is the panel (does the brand make much difference?) and grounding: where to put it, what size wire back to the panel, attaching it to the cold water pipes, etc. Also, is there a way of telling what size the cables from the main disconnect to the service panel are? The main disconnect box is rated as 200A, though it has a 100A breaker for the house. Although it would be good to upgrade the amperage now, I don't know how you tell if the current cables are adequate. Also, do the cables on the OTHER side of the meter (power co. side) need to be investigated? I wonder if I could find an electrician to act in a 'consult' role, and point out everything I would need to do. Would it be pushing it to ask the electrical inspector to look at what is in place beforehand...? Probably.

>6) You're English, huh? I'm an all American, bullet-headed
>Saxon Mother's son. (All the children sing...) So anyway,
>I thought you used the terminology "positive, negative,
>and Earth". We generally call your negative "Neutral,
>which I'm sure you know, but on 120 volt branch circuits
>this becomes confusing to many folks.

Yes, earth...been here three years, so I'm practically American now (*grin*)!. Took me by surprise when I first encountered the 'two hot wires'. "Whats this extra one for?"!

In any case, thanks again. Here's my email if you have any thoughts...I think we've probably lost pretty much everyone elses interest with this many replies now...!
nagoy@home.com

Mark
 
  #16  
Old 03-25-01, 06:53 AM
Wgoodrich
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Nagoy, a metal flexible conduit of any kind is not allowed to be used as an equipment grounding conductor unless that metal flexible conduit is less than 6' long.

Good Luck

Wg
 
  #17  
Old 03-25-01, 09:27 AM
RickM
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Cool

Great posts all!

I, in reading these, saw a couple of things that drew attention to my eye.

1st: The post's title says no grounding at main panel, but later on it was revealed that this is not the main panel, but a sub-panel, or did I mis-read that? It sounds like whoever installed this panel did not wire it correctly, running 3 wires instead of 4. Since there were not grounds to any branch circuits at that time, the installer probably didn't even think of installing the grounding conductor.

2nd: The label that was talked about probably was just a listing requirement, if installed this way (2 wire, no neutral, etc...) Doesn't apply to this installation tho.

To Wg, could you email me the handout for wiring a service? As an inspector, I get questions all the time from homeowners about this. If I find it useful, can I make copies of it to handout? I have some, but they are prety generic. Any information I can use for homeowners can only help those homeowners requesting such information!

thanks to all!!

Rick
 
  #18  
Old 03-25-01, 10:46 AM
Wgoodrich
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Rick email me, I don't know if I have your email address. wgoodrich@tds.net

A couple of things I want to mention, there are some local Utillty Company rules you might want to warn those you give it to that you may not need in your area. Also I plan to send this pass out in msoffice2000. Just email me and confirm you can open or convert msoffice2000 in word form.

Wg
 
  #19  
Old 03-26-01, 02:14 AM
Nagoy
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Hi RickM,

>1st: The post's title says no grounding at main panel, but
>later on it was revealed that this is not the main panel,
>but a sub-panel, or did I mis-read that?

Yes, its the main panel. I think sub-panel's were mentioned in later replies (from Wg's handout, I understand the term 'sub-panel' is not an NEC-recognised term!).

>2nd: The label that was talked about probably was just a
>listing requirement, if installed this way (2 wire, no
>neutral, etc...) Doesn't apply to this installation tho.

It was a separate label that looked newer than the main label, which just concerned me a little. But I think its just a red herring.

>To Wg, could you email me the handout for wiring a
>service? As an inspector, I get questions all the time
>from homeowners about this. If I find it useful, can I
>make copies of it to handout? I have some, but they are
>prety generic. Any information I can use for homeowners
>can only help those homeowners requesting such
>information!

I read the handout, its full of info - one constructive comment from a homeowners pov; a diagram or three would be really beneficial. From trying to read lots of the postings here recently, just wanting to understand more about home electrics, I think theres terminology and jargon that trips people like me up, at least as far as cable and equipment from the 'outside world' to the service panel (or from there to a sub-panel) goes. A couple of diagrams showing what attaches to what, where, and the technical name, would clarify a lot of the details. I found myself a bit overwhelmed. However, I do understand that before embarking on a major project, a good understanding is required, and the terminology would normally be known to an electrician. Hope this is a useful view - but then again, its a free handout that Wg's not being compensated for his time in putting together....! Wg, maybe you should stick it on a freebie web site as you'll be getting inundated with requests soon!

Rick, as an inspector, if a homeowner asked you what he needed to do an upgrade like this to code, would you pre-inspect the site and tell them what they needed to do, or would you point them to a qualified electrician? I'm just wondering whether to call my inspector at this early stage or not.

Thanks - Mark

PS If this thread is exhausted or getting too specific, I'm happy to accept email from anyone interested, or post more general questions later.
 
  #20  
Old 03-26-01, 09:46 AM
J
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Join Date: Sep 2000
Location: Fayetteville, NY, USA
Posts: 1,052
Received 1 Vote on 1 Post
Nagoy,

1) "Total safety" reassurance is expressly based on verification by reliable volt meter. Additionally, if this is a fused main service disconnect removal of the fuses using an approved fuse puller is recommended for an added measure of "total safety".

2) Wiring diagram would be good, I agree. I'd always wanted to do one after I completed my service installation. I'm an electrical designer at an engineering firm, primarily industrial design, but came from a residential, field based career. I can draft this design in Autocad format, but can't readily share it with others who don't have the software.

3) I never did receive an e-mail from you. I always answer my e-mail, except for spam of course. Look for my e-mail to you, and you can capture my address. I can go into a little more detail regarding some of the more detailed questions you asked in here in terms of panel brands, wire sizes, etc.

Juice
 
  #21  
Old 03-26-01, 01:02 PM
Guest
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I'm have been folowing this post. I'm going to be upgrading my panel in the near future. I was wondering if if JUICEHEAD and WGOODRICH could email me some information on this. My email is pentavolvo85@home.com.

Thanks

 
  #22  
Old 03-26-01, 05:15 PM
RickM
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Cool

Nagoy, what we have here is a failure to communicate. When you say "main" you must mean the panel where all the breakers are, correct? When I say "main" I mean the code defined location of the service disconnecting means. This is, if I rean your posts correctly, the disconnect outside, under your meter. This is the service, and this is where all your grounding is required to take place. At this location you are required to tie your incoming neutral to the various grounding points. From there, when ever you have another panel(sometimes called a sub-panel, sometimes a main panel), you are required to seperate the grounds and neutrals. That is the reason for requiring a 4 wire feeder from the service to any panel.

You asked if I would assist a homeowner in deciding what he had to do to upgrade a service, and my answer wold be, sure, if I can. This is more of a public service to our customers (the ones within my area) than something an inspector is obligated to do. I will not design the work for them, but I can give handouts, and talk to them. This is for a couple of reasons. One to make sure they get the right information (such as meter socket height, mast size etc...), but it also allows me the chance to see if they are able to understand just what they are wanted to do. If I get the feeling that it is over their head, I will recommend that they get a licensed electrical contractor in to assist them, or to complete the job.

Hopefully this has answered your questions.

Good luck

Rick
 
  #23  
Old 03-26-01, 05:17 PM
RickM
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Cool

Nagoy, what we have here is a failure to communicate.

When you say "main" you must mean the panel where all the breakers are, correct? When I say "main" I mean the code defined location of the service disconnecting means. This, if I read your posts correctly, is the disconnect outside, under your meter. This is the service, and this is where all your grounding is required to take place. At this location you are required to tie your incoming neutral to the various grounding points. From there, whenever you have another panel(sometimes called a sub-panel, sometimes a main panel), you are required to seperate the grounds and neutrals. That is the reason for requiring a 4 wire feeder from the service to any panel.

You asked if I would assist a homeowner in deciding what he had to do to upgrade a service, and my answer would be, sure, if I can. This is more of a public service to our customers (the ones within my area) than something an inspector is obligated to do. I will not design the work for them, but I can give handouts, and talk to them. This is for a couple of reasons. One to make sure they get the right information (such as meter socket height, mast size etc...), but it also allows me the chance to see if they are able to understand just what they are wanted to do. If I get the feeling that it is over their head, I will recommend that they get a licensed electrical contractor in to assist them, or to complete the job.

Hopefully this has answered your questions.

Good luck

Rick
 
  #24  
Old 03-26-01, 05:48 PM
Nagoy
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>Nagoy, what we have here is a failure to communicate.

More a failure on my part to call equipment by their correct names. I'm beginning to realise my terminology is all wrong (Juicehead helped me see my errors, too).

>When you say "main" you must mean the panel where all the
>breakers are, correct? When I say "main" I mean the code
>defined location of the service disconnecting means. This,
>if I read your posts correctly, is the disconnect outside,
>under your meter...

Yes, that was my mistake. I knew what I had and what I meant, but I described it with completely the wrong words! Apologies to all. From my weekend investigations, there 'may' be a grounding wire at the "code main" but I haven't discovered where it comes from or goes to yet. There certainly does not seem to be a ground wire from there to the breaker panel, though there is to the AC. I would like to take a digital pic of this last element, and post it to complete the storyboard (and fix it so the links work properly, too).

>You asked if I would assist a homeowner in deciding what
>he had to do to upgrade a service, and my answer would be,
>sure, if I can....

Thanks, Rick. Thats useful to know. Hopefully my local inspector will be as useful and friendly.

My next post will show all my equipment (errr...bad choice of words again!), that way I won't confuse everyone, myself particularly.

Sorry for the confusion! This still isn't the longest thread on Electrical, so I'm not giving up quite yet Plus theres at least one other person following it, so its serving some use....maybe....
 
  #25  
Old 03-26-01, 08:03 PM
Nagoy
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Finally a working link. Hope this clarifies my mistaken jargon!

http://www.geocities.com/mark_britboy/img/electric.htm

Three specific questions:

1 - How would you send a ground wire to the main breaker panel from the main disconnect, if there are only three bonded positions and all of them are taken up? There are two screws (you can just see one at the rhs) that are labelled for grounding equipment. Seem a bit puny though.

2 - Given that I have no idea what size the cables are, would it be wise to replace them with 200A sized cable, for future proofing, if I'm installing a 200A rated panel downstream?

3 - Does the utility co have to inspect cable on their side of the meter for 200A service? In other words, given I replace the cable, do I have to do more than replace the 100A breaker with a 200A one?!

Uh-oh, I know I said three questions, but this last one is an important one:

4 - What do I do about the existing armor-grounded circuit(s) if I replace the panel with a grounded one. Would I have to replace them? I don't know where they're grounded. Oh no...now, that will be a pain.

Thanks for persevering!
Mark
 
  #26  
Old 03-28-01, 10:35 AM
J
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Finally, I've seen a picture of your "service equipment". (By the way, you and I have discussed this, and if you call that box by that term most everybody who's knowledgeable enough to contribute here will know exactly what you mean. Maybe you'll start calling the other panel "the house panel" or something to distinguish it. (It's the load center with the caption "Main Service Panel", which is a misnomer Nagoy now realizes I think.)

In the upper photo I see the 100 amp breaker that feeds the house panel (it's a sub-panel technically, where all Nagoy's normal branch circuits terminate), and I see the 2-pole/40 amp breaker on the bottom that feeds your AC unit. I also see the copper buses that come over from the adjacent meter compartment. Say, a picture really IS worth a thousand words!

Some general answers, by number:

1) Space in this enclosure is really tight. Ideally what you would need to do is buy a simple ground bus with at least 3 spaces, and adequate size holes to accomodate #4 or larger wire. Find a suitable location in which to install the new bus, sand off all the paint in the area where you will mount it, and screw it securely to the enclosure. The proper type of screw often comes with the bus. Then remove one of those ground wires and install it on the new bus. Run a new #6 bare wire from the point where you removed the existing ground to one of the spaces in the new bus. Now you have at least one additional space for a new ground wire to your house panel.

2) Yes it would be wise orinarily. But you have mentioned that the service equipment panel is rated 200 amps. You can't install a 200 amp breaker in place of the 100 amp breaker because that will total 240 amps. But, you CAN install a 150 amp breaker there and you'll have only 190 amps. Since you're mainly looking for more spaces you're going to like this: A 150 amp panel with 30 spaces can be had at Home Depot for as little as $119. It's a Square D "Homeline" panel. This is what I installed in my house last year and I'm completely satisfied with it. The package I bought included a 30 amp/2-pole breaker and a couple 1-pole 15s and 20s for that price. Yours could even be less, because you only need a "Main Lugs Only" (MLO) panel (Not a "Main Breaker" panel) because you already have the breaker to that panel in your service equipment panel. Ask the salesman for a 30 space ground bus, since you'll need to have separate grounds & neutrals in the new house panel. The additional bus costs $8 - $10 I think. Then additional breakers are less than $4 each for single pole 15s & 20s.

Leaving that 100 amp breaker in place will allow you to install a 150 amp panel downstream without having to increase the cable size. If you want to replace it anyway, you'll need 2/0 aluminum for 150 amps ,again using NEC 310(15)(b)(6). I would buy type "SE-R" cable, which is a single cable with 4 conductors, one of which is a bare ground. Before you do, verify that the 100 amp breaker will accomodate that gauge wire. Many breakers are labeled as to allowable conductor size. With a 150 amp panel and 150 amp cable, you can always have the main 100 amp breaker replaced in the future as needed and everything downstream will be already rated for it.

3) The main thing here is your SE cable. If you just can't determine what gauge it is from the jacket labeling, being painted or whatever, an electrician or the utility could tell. Sometimes a utility won't come unless there's a problem though. (For a free service call you could always toss a spanner inside the panel and run!) To handle your 200 amp rated main (service equipment) panel the SE cable must be 2/0 copper or 4/0 aluminum cable, using NEC Table 310-15(b)(6) for "services". If not I wouldn't touch either of the existing breakers in that service ewuipment panel. It may have been OK when installed originally, but the 1999 NEC prevails if anything changes in that panel.

4) When you replace the house panel, you simply transfer whatever existing circuits to the new panel as-is, including the armored cable ones. You didn't have a proper ground there before, so nothing has changed. You can always figure out a way to run a ground wire from the ground bus in the new panel all the way to those receptacles later. First you have to put in a panel with a ground, though, and you'll just have to tell yourself that you can't save the world in one step!

Time to throw myself out of here. Hope that helped.

Juice
 
  #27  
Old 03-28-01, 04:01 PM
Wgoodrich
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I think we need to stop here a while and talk this one over.

Juice,

you suggested intalling a 150 amp breaker. Did you mean installing a 150 amp breaker in that existing main service disconnect?

I notice that there is not plastic bushings protecting these larger wires.

I also noticed that we have an SE cable running from this main disconnect to the house sub panel and that SE cable does not include a bare grounding conductor.

If you are suggesting to replace the 100 amp main breaker with a 150 amp main breaker I believe that you would be exceeding the maximum rating of that main panel. I suspect if researched that main panel is only 100 amp rated.

It is my opinion that this panel system is a very busy panel system. If it was mine, I would start at the beginning and build a new 200 amp service for that structure.

Before I suggest that for sure I need a clearification on the meter base to this main disconnect. Is this meterbase a part of a multi metering system for other dwellings like and apartment building? Why the buss bars feeding that panel. This concerns me a bit. Also how far into the dwelling do you have to go to get to the non service rated panel [sub panel] from the main service rated disconnect?

I'd like to talk about this one, it looks awful busy to be adding to.

Wg

 
  #28  
Old 03-28-01, 04:44 PM
Nagoy
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>Is this meterbase a part of a multi metering system for other dwellings like and apartment building?
No, single ranch house.

>Why the buss bars feeding that panel.
Sorry, I didn't understand this question..



I know this thread is getting long, so I'll try and summarise where we are, and add in the details as requested. Also, I think my terminology is much better now :

1- Main disconnect (on the outside side of garage , near garage door) also houses meter in lhs (top picture on web page shows the rhs accessible insides of mains, meter is outside of picture in left half of box). Contains 100A breaker that feeds panel in garage (two hots, neutral) and 40A breaker that feeds A/C (two hots, and a bare aluminium wire - ground or neutral?). Mains appears to be grounded, bare copper wire is bonded to the box, though I haven't located its source. My guess is water pipe, but cannot confirm. Label states mains rated for max 200A (or lower amperage for 'continous' draw).

2 - Breaker panel inside garage on wall shared with dwelling (maybe 30' away?). Rated at somewhere around 100-125A, depending on feeder gauge, which I can't tell. And yes, very busy. And no ground bar.


Main aim - solve 'busy-ness' of panel and provide ground in panel for circuits (existing and/or future). So I thought, may as well also upgrade to spacious 200A panel. I realised this would probably mean replacing cable from mains to panel (SE cable, as described by wg). I would also have to run a ground wire (isolated on panel), though since I have no idea where the copper wire on the mains comes from, I'd have to install ground rod(s) as well at the mains.

Not sure whether 'utility' side of meter cable is suitable for 200A service (or would it have to be 240A, given the a/c breaker). Also, not sure whether I can replace the 100A breaker with 200A in mains (again, totals 240A in box).

Additional complication is there is at least one circuit that is armored and grounded 'somewhere'. What would I do with this possibly very long circuit if I complete the above project (ie, can you 'bond' armor to ground bar in new panel???). Because of this current attachment, the panel IS grounded, but only by means of this armored cable.

Final thought, especially regarding the A/c, and max amperage of mains and cables: what if I disconnect the A/c from the mains, and run it as a circuit from the breaker panel. Wg, you calculated my required service a couple of months ago as approximately 150A (see http://forum.doityourself.com/showth...readid=44538). This I think excludes the a/c, and includes a couple of fantasy 'options' like whirlpool and hot-tub (dream on....).


Mark


 
  #29  
Old 03-29-01, 01:25 PM
J
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Nagoy,

One advantage to using the Forum is a variety of thoughts. Wg, for example, suggested that if this were his service he'd start from scratch. On that note, trying to minimize what truly needs to be done I have approached your situation in terms of saving what you can. I may have steered off course. The other guys are right, in truth that existing main panel is a mess. I will try to simplify an explanation of a whole new system, which ideally is best. Starting from the top down:

1) Utility aerial conductors, called "service drop". Utility provides this.
2) Weatherhead: you buy & install. Size must match SE cable size. Mount next to existing, remove existing after cut-over.
3) SE cable: Type SE-U, 4/0 aluminum for 200 amp service. SE cable enters bottom of weatherhead, outer jacket is stripped off here and 3 individual conductors protrude from "face" of weatherhead. Leave ample excess length for utility connection. Run SE down the house parallel to existing SE, remove existing SE after cut-over. Terminate at new meter socket, 3 wires only, no ground.
4) Meter socket: Most utilities require you buy & install this. Check with yours to see, you must buy a type they approve. (Most utility companies will send you a copy of their specifications for free on request.) Try to get a completely separate enclosed meter socket, unlike your present one. Utility will provide the glass meter assembly during cut-over.
5) SE cable: run more of the same cable (as #3 above) from new meter socket to new Main Disconnect. Terminate at the disconnect "line" lugs. Still 3 wires only, no ground (until #8 below).
6) Main Disconnect (Will be your "Service Equipment"): Rated 200 amps/240 volts/single phase/3-wire. Since it's outdoors its enclosure should be rated "NEMA 3R". (Choice of this disconnect style assumes you will feed the AC from the new indoor "house panel" in the future - a great idea and much simpler design.)
7) Ground Rod: 5/8" x 8' galvanized steel or better (copper). Requires UL listed grounding clamp. NEC requires 1 rod, some utilities require two, check w/your utility. If two, NEC spacing is no closer than 6' between them. Top of rod should be 6" below grade. Dig 6" trench between them to run connecting wire. Leave trench open until inspection is done.
8) Grounding Electrode Conductor: #4 stranded bare copper. Terminate in Service Equipment (Main Disconnect). Connect one end to ground bus, run through first and second grounding clamps at rods and back to ground bus in one continuous loop. When running up outer wall to Main Disconnect, run in 3/4" schedule 80 conduit (NEC protection). Tighten all connections securely.
9) SE-R cable: 4 conductor cable with overall outer jacket. Three 4/0 insulated conductors (2 hot, 1 neutral) plus 2/0 AWG ground. (This is the way Alcan Stabiloy brand is sold. May vary by mfr. If individual conductors were run in conduit, for example, hots = 4/0, neutral can be 2 sizes smaller = 2/0, and ground = #4 min. (With increased "non-linear" loads of computer & home electronics equipment NEC now recommends but does not require "full-sized neutral, your option.) Connect 3 insulated conductors to load side lugs of Main Disconnect. Connect ground to ground bus of Disconnect. Run this cable to new 200 amp house panel.
10) House Panel: 200 amp/240 volt/single phase/3-wire/30 spaces. Purchase one 30 space or two 15 space
ground bus bar(s). This is technically a sub-panel and neutrals & grounds must be completely separated. Panel will come with a "bonding" screw. (It connects the neutral bus to the steel enclosure thus connecting it to grounds.) Throw it away.
11) When utility comes for cut-over (after satisfactory inspection) you will terminate hot & neutral conductors from the SE-R cable at appropriate lugs while they are up above cutting over their aerial conductors to your new SE cable conductors. Ground conductor is terminated on the ground bus on the enclosure wall.

From here all you're left to do is transfer your existing circuits over to the new panel. I won't go into that at this time. If you install the new weatherhead, SE cable, meter socket, Main Disconnect, SE cable and house panel next to the existing without connecting any of the new stuff, the cut-over will be fairly easy. Won't get into that now either, but will be happy to during "construction". Just wanted to put this complete system in order, as we've been jumping around between top and bottom and what-ifs, etc.

To my colleagues, lot of detailed info & stats included and drawn mostly from memory, so if you spot an error please don't hesitate to correct. I'll thank you for your assistance.

Juice

[Edited by JuiceHead on 03-29-01 at 04:33]
 
  #30  
Old 03-29-01, 03:07 PM
Wgoodrich
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Juice

I picked up something that tells me we both have been overlooking something or I am totally confused at this point.

The way that I am picking up his set up is a meterbase/four circuit disconnect combo as one unit outside carrying a two hundred amp sub panel inside in the garage and a 100 or 150 amp sub panel in the house, fed from that two hundred amp sub panel in the garage. This sub panel from a sub panel seems to be located in the house which also seems to be a seperated building from the garage.

Also be careful Juice this post seems to be in two different post in this forum.

Nagoy, is this what you have, or am I totally lost ?

Wg
 
  #31  
Old 03-29-01, 06:31 PM
Nagoy
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>The way that I am picking up his set up is a
>meterbase/four circuit disconnect combo as one unit
>outside carrying a two hundred amp sub panel inside in the
>garage and a 100 or 150 amp sub panel in the house, fed
>from that two hundred amp sub panel in the garage. This
>sub panel from a sub panel seems to be located in the
>house which also seems to be a seperated building from the
>garage.

>Also be careful Juice this post seems to be in two
>different post in this forum.

>Nagoy, is this what you have, or am I totally lost ?

Wg, sorry if this is getting confusing, but no thats not right. Theres only one sub-panel (~125A), its in the garage (on the wall shared by the house and garage - which is attached). Its the bottom 'busy-looking' panel on the web page link. For readability, I showed two pictures of the same diagram / label (top and bottom halves).

The meter and mains disconnect is outside the garage (a garage walls-length away), and yes its a combined unit. It has a 240V 100A breaker for the above breaker panel. The unit is rated as 200A according to its label. In the photo link, its the top picture (the meter-half is to the lhs and out of the picture). A three wire cable snakes its way from here, inside the garage to the above breaker panel.

The other post I have running is concerning the second breaker in the mains disconnect - a 240V only (no neutral) 40A breaker to the A/C that had the bare aluminium cable that you recently explained.


I know you answer dozens of posts daily, but if part of the confusion has been my descriptions, I apologise. I'm not sure where you got the 'panel inside house' idea, but I gave a more detailed description of the setup a few posts up from this one.


Also drew the layout, added to top of the link:
http://www.geocities.com/mark_britboy/img/electric.htm


Mark
 
  #32  
Old 03-30-01, 09:18 AM
J
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Nagoy,

Good show! That diagram was very clear. That's the way I pictured the system. what application did you draw this in?

Now, a question about that armored cable. I think that in one of my replies I mentioned that years ago, '60s and earlier, a #10 insulated ground wire was sent from a panel to the water piping entrance housed in armored cable. If it disappears into a wall somewhere you can determine its contents by taking the panel face off and looking for a single conductor, terminated on the ground/neutral bus, exiting the panel via the armored cable, which is typically of smaller diameter than the others I see in your photo. (Understanding of course that ground and neutral should have separate buses in a sub-panel such as this, but nevertheless might be how that panel was wired once anyway.)

I was also wondering what you made of all that info I posted yesterday. I would guess, based on upstate NY prices, that the system I described would have a ball-park shopping cart price tag of about $750, which includes the inspection and permit fees. This excludes labor.

Wg, always a comfort to have you riding shotgun out there on my replies. Thanks!

Juice
 
  #33  
Old 03-30-01, 02:39 PM
Nagoy
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Juice - just did a quick drawing in MS Paint. Seemed to do the job.

The armored cable is not itself a ground wire. Its a no-ground wire circuit (to the kitchen and beyond). The grounding symbol was to show that the armor appears to be grounded somewhere along its length, since the receptacles on the circuit are grounded when screwed back into their box. I have no idea where this attachment could be. It could be anywhere.

The panel only has a neutral buss, no ground. There are as many white neutrals on this buss as there are cables entering the panel (including the feeder), no more, no less. So no extra ground wire there.

The info you posted was very useful indeed. What I'm leaning to at the moment is to get quotes for an electrician to deal with the outside (new cables from drop, and to the panel inside, ground rods, possibly new meter / mains), and leave me the inside part of setting the new panel and subsequently hooking up the old circuits to the new panel, if this was significantly less expensive. Of course, I still might just end up writing a big check
In any case, I still feel everything I'm learning now is just as important as if I did it myself.

(I found another length of armored cable in my garage yesterday . Get this; it was being energised by having the receptacle from an extension cord somehow 'wired' to the end of it (ie not powered from the panel), another weedy extension cord was plugged into that, and the other end went to another receptacle from another circuit! needless to say, thats disconnected now! thats why I don;t mind the disparaging comments about the panel, it wasn't me that did it! Though I do want to fix it all up)

Sorry for not responding yesterday - someone knocked over my motorcycle outside my house, so I was in a bad mood all day

 
  #34  
Old 03-31-01, 07:12 AM
solipsist9
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Thumbs down

>

i need to take issue with this. you're wrong about this not being a great ground. this is a better ground than having a ground wire, especially conduit. ground wires rely on the splice for an effective, which many times mean they're not done properly by non-electricians; ie., wire nut loose, too many wires in splice, etc. a metal cable or conduit system is a much better and safer system than romex any day.

i've followed this conversation. i'd like to add that when using se cable (or any wire, actually), you are ALWAYS better off using copper conductors instead of aluminum. aluminum wire, while used frequently, is also prone to problems.
john


 
  #35  
Old 03-31-01, 09:37 AM
J
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Nagoy,

Sorry to hear about your bike. Hope it wasn't damaged too badly. Glad to have contributed to your knowledge base. As far as hiring an electrician, keep us posted. We'll always be happy to jump in and help with questions. Also interested in how the story progresses. Good luck.

Solipsist9, While there's no question that copper is by far a superior conductor, I find nothing wrong with aluminum in the larger gauges. If anti-oxidant is used and connections are properly torqued the cable and terminations will last forever.

I must disagree with you on what is a more reliable ground. First, I believe Wg said recently that armored cable is not permitted to serve as an equipment ground. He may have cited code on this, I don't remember. But a continuous copper conductor is, in my opinion, the superior ground. Ands I trust splices more than EMT fittings by far. I have seen many instances of conduit sections slipping apart or having been knocked apart. In all my conduit runs I always provide an equipment grounding conductor. There's no question that conduit and armor provide superior protection from physical damage, but I would not trust them with my life.

Juice
 
  #36  
Old 03-31-01, 10:01 AM
solipsist9
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>

i've been an electrician for over 20 years, and aluminum does not always last forever, even with anti-ox paste. aluminum has greater resistance and is therefore susceptible to creating more heat than copper. this leads to greater chance of oxidation and loosening on the connection due to the constant expansion and contraction of aluminum. aluminum tends to "collapse" much easier than copper, so a connection installed may need re-tightening soon after, but no electrician ever does this. i have seen aluminum connections that were installed years earlier become defective, even though they were installed properly. at issue is how close to ampacity the wire is used. if the wire comes close to max, heat will eventually conquer aluminum. aluminum wire is banned for certain uses in many localities because of problems, and fires. the reason why electricians use aluminum is $. notice also who is on the code-making panels for the nec. there are several from aluminum manufacturers. i've never used aluminum and never will. the only time i've worked with it (about 50 times) is when i've been called in to fix a problem.

>

wg is wrong. the metal armor is allowed as an equipment ground. conduit "slipping" apart is due to poor workmanship, not equipment. i have never had conduit that i've installed come apart, and all i've ever worked with is conduit. (no romex allowed in chicago; all emt) i have even had to pull wires through large conduit with a rope attached to my truck, and ropes have broken before there was any chance of fittings coming apart. nec provides MINIMUM standards. nec assumes good workmanship, and any equipment installed incorrectly is problematic. i agree that continuous copper is a better ground but only from the standpoint of resistive qualities. the potential lies in the continuity of the copper. physically, there is a much greater chance of soft copper wire breaking or a splice coming apart than there is of a conduit or ac cable fitting coming apart. all that i speak of is from experience, not opinion.
personally, i will never use romex in my own home. romex in the electrical field is a result of fiscal frugality, not quality. but then, construction in general is far inferior in methods and materials than it was years ago. houses today are essentially disposible. they are not designed to last.

Juice [/B][/QUOTE]
 
  #37  
Old 03-31-01, 11:30 AM
J
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Solipsis9,

I copied our discussion to a new thread "Aluminum wire/Raceway ground", as this one already stretches from Chicago to L.A.!

Juice
 
  #38  
Old 04-01-01, 01:36 PM
Wgoodrich
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solipsist9

You said;

wg is wrong. the metal armor is allowed as an equipment ground.

I said;

Boy now you done went and did it. Ya turned Wg on AGAIN !

Just kidding, I respect the American way and believe that everyone has the right to think and speak what they blieve. However I strongly promote knowledge. In promoting knowledge for everyone to learn, including my self, that freedom of speach can become more valuable in my opinion thus allowing those who listen to make an unbiased, informed decision of their own.

The subject originally was bx cable and flex or armor,from a rather old wiring system. No comment at the time was there made about type MC or AC cable. These posts seem to fly off on many other branches of subjects yet mixing in quotes of the original post. Juicehead is correct quoting what I said that flex is not allowed in that scenerio of that post using a bx cable's armor or flex as an equipment ground in excess of 6'. This statement was referring to the old style installation that this post was concerned about. Back when this installation was installed, I challenge anyone to find a listing or label approving the use of that older style flex used for BX cable to be used as a grounding conductor in excess of 6'.

As far as I know bx cable is no longer even listed for use as new intallation.

The following is the Code article pertaining to metallic tubing used as a grounding conductor.

ARTICLE 349 -- Flexible Metallic Tubing
349-5. Uses Not Permitted
6. In lengths over 6 ft (1.83 m).

The following is the Code article pertaining to types of equipment grounding conductors.

250-118. Types of Equipment Grounding Conductors
The equipment grounding conductor run with or enclosing the circuit conductors shall be one or more or a combination of the following.
1. A copper or other corrosion-resistant conductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or a busbar of any shape.
2. Rigid metal conduit.
3. Intermediate metal conduit.
4. Electrical metallic tubing.
5. Flexible metal conduit where both the conduit and fittings are listed for grounding.
6. Listed flexible metal conduit that is not listed for grounding, meeting all the following conditions.
a. The conduit is terminated in fittings listed for grounding.
b. The circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less.
c. The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground return path does not exceed 6 ft (1.83 m).
d. The conduit is not installed for flexibility.
7. Listed liquidight flexible metal conduit meeting all the following conditions.
a. The conduit is terminated in fittings listed for grounding.
b. For trade sizes 3/8 in. through in., the circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less.
c. For trade sizes in. through 1 in., the circuit conductors contained in the conduit are protected by overcurrent devices rated not more than 60 amperes and there is no flexible metal conduit, flexible metallic tubing, or liquidtight flexible metal conduit in trade sizes 3/8 in. or in. in the grounding path.
d. The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground return path does not exceed 6 ft (1.83 m).
e. The conduit is not installed for flexibility.
8. Flexible metallic tubing where the tubing is terminated in fittings listed for grounding and meeting all the following conditions.
a. The circuit conductors contained in the tubing are protected by overcurrent devices rated at 20 amperes or less.
b. The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground return path does not exceed 6 ft (1.83 m).
9. Armor of Type AC cable as provided in Section 333-21.
10. The copper sheath of mineral-insulated, metal-sheathed cable.
11. The metallic sheath or the combined metallic sheath and grounding conductors of Type MC cable.
12. Cable trays as permitted in Sections 318-3(c) and 318-7.
13. Cablebus framework as permitted in Section 365-2(a).
14. Other electrically continuous metal raceways listed for grounding.

I think that you will find that empty flexible metallic conduit with wiring installed in the field is approved only if listed and labled for use as a grounding conductor. If this flexible metallic conduit is used as a grounding conductor then it must be used with connectors that are also listed and labled for use as a grounding conductor.

I think that you will find the flexible metallic tubing is still limited to use as grounding in lengths of 6' only.

I think that you will find the metal clad to contain a grounding wire if listed as metal clad equipment and does not rely on the use of the metallic flex as a grounding path. Then you will again have to use connectors approved for use as a grounding path if that flex was used as a grounding path.

I think that you will find that type AC cable will contain an aluminum strip in that type AC flex of that type AC cable. This aluminum stip is required and designed to augment the flex to be the grounding conductor and you again must use connections listed and approved for that type AC cable as a ground path.

Now as for use as aluminum wiring, although I do not practice the minimum safety standards, only, and do not try to promote the use of aluminum wiring, the minimum safety standards accept its use.

I am hard pressed to believe anyone active in this forum including myself to be better skilled in the electrical industry, to the point of having the qualifications for challenging the minimum safety standards as one person alone, considering that the NEC is created by so many highly skilled people throughout the United States.

I still believe the power of many very educated minds in the electrical field is better than just one person. No matter how smart that one person is. Just remember that the NEC is the minimum safety standards only.

I still believe that if we try to promote knowledge as to what is accepted as the minimum safety standards. Then each person has the right to make his own informed decision. You might talk on what you would do if it were you. You might even speak of past experiences in your career, that is your right of freedom of speach. However trying to convince someone else to believe what you believe while condemning the opinions of accepted rules of safety formed by many, may be stepping beyond your abilities. I would be reluctant to speak of condemning anything that is accepted to meet the minimum safety standards. If it were me, I would speak of what the minimum safety standards are, what I feel and have experienced, then advise them to make their own informed decisions.

As for nonmetallic sheathed cable being condemned, I would like to point out that the trend is ralaxing allowing nonmetallic sheahed cable to be installed almost everywhere including most commercial buildings. Non metallic sheathed cable is limited in few places like places of assembly, explosion proof areas, and the like. Just a few places left where nonmetallic sheathed cable is not allowed. Seems that the track record of this cable is showing a reason to have much more confidence in its use and safety. Yet you tend to condemn what seems to be a product making leaps and bounds in track records of safety and acceptance.

Good Luck

Wg
 
 

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