Fitz's continuing electrical saga


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Old 07-07-15, 10:31 AM
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Fitz's continuing electrical saga

Hello guys. I thought it would be better to start a new thread than continuing asking questions on the old one, found here...

http://www.doityourself.com/forum/el...ml#post2427529

So..I'm back.

Ok guys, I've researched as much as I can, and asked the electrical sales guy at Home Depot a bunch of questions, before I purchased everything I needed, and then some. However, as many questions I asked, I'm still confused about some things, as he seemed hesitant to explain some things, so my only option is to ask them here, before I settle on my plan.

First off, can someone explain what a load center amperage rating is in relationship to?

Second, In relationship to the first question, I've seen many load centers with total breaker amperage that exceeds the amperage rating of the load center they are in. Can you explain that for me?

Third. What is the smallest diameter PVC conduit that can carry (4) #2 AWG aluminum conductors?

Forth. Can I cut holes in a panel for conduit termination if the existing knockouts aren't large enough nor enough of?

I've run into some problems and need to know these answers before proceeding. I'll explain later. Thanks
 
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Old 07-07-15, 10:58 AM
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Load center is a term that some manufacturer's use for a circuit breaker panel, often one of less than the maximum allowable circuit breaker capacity.

[It used to be that a "standard" lighting and appliance panelboard, the term used in the NEC, had a maximum of forty two circuits. I know that particular number no longer is the maximum but I don't know if there is now no maximum whatsoever.]

The maximum amperage rating for any panelboard is just that; the maximum amperage that it can be supplied with from the utility or in the case of a "sub-panel" (that designation does not exist in the NEC) the maximum size of of the feeder circuit from the service panel to the sub-panel. Note well that the cumulative ratings on all the branch circuit breakers may be several times the maximum amperage rating of the panelboard. In my own case I have over 900 amperes of circuit breakers all being fed from a 200 ampere main circuit breaker.


What is the smallest diameter PVC conduit that can carry (4) #2 AWG aluminum conductors?
You should get yourself a copy of Ugly's Electrical Reference at your local big box mega-mart homecenter. As I recall it is about $10 and it has a wealth of information, including the answers to almost every question you have asked in your many posts.

Conduit size depends upon the outside diameter and number of the individual conductors. Since different insulation types have different thicknesses it is necessary to look up in the table for the specific insulation type to determine the conduit size. Also, different conduit types have different inside diameters, especially when discussing the difference between PVC schedule 40 and PVC schedule 80. It appears that 1-1/4 inch schedule 40 PVC would be the smallest conduit that you could use. Remember, going one size up in conduit often makes the job of pulling the conductors MUCH easier at only a slight increase in cost.


Can I cut holes in a panel for conduit termination if the existing knockouts aren't large enough nor enough of?
Absolutely!
 
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Old 07-07-15, 11:06 AM
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what a load center amperage rating is in relationship to
It is the maximum amperage it can carry. When it is a sub panel it is the largest size breaker that can be used to protect it. However on subpanels often a smaller then maximum breaker is used to feed it and the size of the wire is based on the breaker size.
I've seen many load centers with total breaker amperage that exceeds the amperage rating of the load center they are in.
All of the breakers are never normally supping the full load amp rating listed on the handle. In fact some may have no load at any given time and some only a small load. Panel size is based on expected actual maximum load at any given time.
Can I cut holes in a panel for conduit termination if the existing knockouts aren't large enough nor enough of?
Yes, it is done all the time.
 
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Old 07-08-15, 07:55 AM
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Forth. Can I cut holes in a panel for conduit termination if the existing knockouts aren't large enough nor enough of?
If you can borrow or rent an electrician knockout punch set it makes that job much better & cleaner than a hole saw.
 
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Old 07-08-15, 09:22 AM
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the electrical sales guy at Home Depot a bunch of questions, before I purchased everything I needed, and then some. However, as many questions I asked, I'm still confused about some things, as he seemed hesitant to explain some things
You were lucky to get some questions answered at all. The big box store sales guys are hired to give customer service and show you where products are stocked and not to provide information. Most likely you quickly got to the end of the sales guys knowledge. Occasionally you will find one who really knows his stuff, but it's a rarity.
 
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Old 07-15-15, 08:35 AM
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Hello guys! Sorry I haven't been back. Too much work..too little time. Thanks for the answers.

Well, to make a long story short, I'm ready to pull the 4 wire system through the 2" conduit today and hook up everything to the new load center. Here it is...

Eaton Cutler-Hammer 125-Amp 6-Space 12-Circuit Outdoor Main Lug Load Center-BR612L125RP - The Home Depot

However, I'm really pushed for time, and I have a quick question. Originally, I bought a similar SquareD panel, but after doing a preliminary Sketchup wiring model, I decided this panel was much too small. Even as the new panel is much larger, I still have reservations about room in this box, as I have the house feed, and the SE from the fuse box, all of which are #4 copper, and the garage feed, which is #2 aluminum. My question is.. what is the minimum bending radius for these wires? Reason i ask is, I looked up one chart, and for #2 aluminum, it said the radius was 3". Well..I don't even have 3" clear from the side of the panel to the breaker lugs. Which leaves me wondering why the panel manufacturers don't consider this when designing their panels?

Anyway, what is the standard operating practice here? It would seem, that for these size wires, all you can do in a small panel is use the minimum radius the box allows..no? Any help here would really be appreciated.

And btw, I have lots of pics now, and will get back here to get on with the garage electrical stuff. but for now, I just need to get this garage feed hooked up. Thanks.
 
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Old 07-15-15, 09:24 AM
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There should be plenty of room to make the bends in a modern panel. I usually use a screwdriver handle to make the curve on the larger wires. The panels are designed to accommodate the wire sizes that correspond with the panel's amperage rating.
 
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Old 07-15-15, 10:11 AM
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Hi again. Ok, cool. I did a mockup on the bench, using pieces of the old aluminum wire, and used radius' about 1" to 1-1/2". But, after reading something about too tight of bends isn't good, I started self doubting myself. Any that's good to hear. i can do that. here is the mockup..
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and the Sketchup of the SquareD panel model. ..

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Ok, I just used a small patch of toilet paper tied to a 100' string, and sucked it though the conduit. Then I pulled a rope through using the string tied to it. Now it's time for the 4 wires. Wish me luck. Hahahaha!
 
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Old 07-15-15, 05:42 PM
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OMG.. Spent half hour just taping the individual conductor to the 3 conductor composite..which was 70' long. Then, taped the end of the rope to the composite. ..and pulled it through the conduit. Picked up a few extra things at the local TruValue, and got the grounding bars fastened in both panels. PITA. But I'm on track. Thanks for all the help. More to come.

Meanwhile, here's what I've been dealing with, from the beginning of discovering what I was up against..to actually doing it.

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Meanwhile..wifey discovers this little area could be a "Japanese garden". OMG. Ok..here is the early plan to make this ugly electrical thing become hidden in a simple element of the over all plan to make wifey happy..regardless of code regarding enclosing meters.
Figure it as a civil disobedience, even though it's electrical safe and up to code. Close ups of the finished product in a few days. All I know at the moment is I'm whacked from doing everything I had to do to pull 70' of a 4 wire composite. It's done.

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BTw,
 
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Old 07-16-15, 09:03 AM
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Ok guys. Today is the day to hook this stuff up. But I still have a lingering question regarding the grounding rods. According to a diagram in a local codes booklet, two ground rods are required at the meter kiosk area. At least 6' apart. And at the sub panel too. This is 4 ground rods. Does this sound right?
Also, can i place these grounding rods in the same trench as the conduit? Code calls for them to be buried at least 6" below grade and the trench is already dug. Of course, each set of double rods are at least 40' apart.

Another confusing issue is I saw a video of Mike Holt, saying everything grounded BELOW grade needs to be bonded together, and everything grounded ABOVE grade needs to be bonded together. The question is, are the two sets of grounding rods bonded together by virtue of the grounding conductor in the 4 wire feed which are bonded to each grounding bar in the panels?




Also, the existing grounding rod at the meter post, is bonded to the neutral lug in the old fuse box by a bare copper grounding conductor. Should i move it to the grounding bar in the new load center, as the grounding conductor between the load center and sub panel is bonded to the grounding bar in both panels. Or..does it make any difference? This diagram shows how I am hooking this stuff up. The only thing missing is the fuse box in between the meter and the new load center, and double grounding rods.
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Thanks for any help. I've got to get this hooked up today. Thunderstorms predicted for tonight and tomorrow. ARRRRRRRRGGGGGGGRRRRRR!
 
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Old 07-16-15, 01:02 PM
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Need immediate help with question!!

Hello guys!! I'm right at the point of connecting the 4 wire feed for the garage to the new load center. But something came to my attention that I don't know what to do. As I told in my previous thread, this 4 wire feed is comprised of a 3 conductor twisted composite(URD) and an individual conductor. However, I just discovered something. Two of the conductors in the composite, are #2 AWG USE aluminum, and the 3rd conductor, which in a 3 wire system would be the neutral, is a #4 AWG USE aluminum, with 3 white or yellow stripes. The individual conductor is #2 AWG USE aluminum.

It would seem to me, that in a 4 wire feed, since the individual conductor is #2 AWG, IT should become the neutral with a white tape marker showing it is neutral, and the #4 AWG conductor in the composite, should now become the conductor bonded to the ground bars in the panels, no? I really need to know this ASAP!! Thanks so much.
 
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Old 07-16-15, 01:10 PM
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Not sure I follow you but the neutral can be smaller than the hot. #4 is smaller than #2
 
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Old 07-16-15, 05:07 PM
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Ok Ray. That's all I needed. Thanks a million. Btw, I know I let a lot of stuff out of this thread, but it's only because of the demands of daily reality, lot's of pics to follow. They will explain the totality of what I am doing. Thanks again. I mean it.
 
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Old 07-17-15, 05:24 PM
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Well, to make a long story short, I'm ready to pull the 4 wire system through the 2" conduit today and hook up everything to the new load center. Here it is...

Eaton Cutler-Hammer 125-Amp 6-Space 12-Circuit Outdoor Main Lug Load Center-BR612L125RP - The Home Depot
I don't see a main breaker or disconnect anywhere unless in your mockup the 60 amp breaker I saw was to be used as a backfed main breaker. If that's what your mockup was showing, you'll need a main breaker retaining kit for the 60 amp breaker.
 
 

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