240V receptacle for table saw


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Old 07-19-16, 03:27 AM
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240V receptacle for table saw

Hi - I have a new table saw and had an electrician update my subpanel in my barn to 240V. I now would like to run a line and install the dedicated outlet for the machine and just want to confirm i'm doing things to code.

The machine specs:
- 240V single phase
- 23A Minimum Circuit Size
- 30A Connection
- L6-30 Power Cord

A few questions for the experts...

1 - My subpanel is connected to a ground wire that comes in from the main panel in the house. Should I also ground the subpanel box in the barn to a pipe or something nearby?

2 - Is regular 12 gauge cable with 2 wires and ground sufficient for the run from the sub-panel to the outlet?

3 - My workshop is in a room within the barn and I have both romex and BX cables running to existing outlets and lights. This cable run would be within the joists of the above floor and well out of the way. Is it ok to use romex or do I need to use conduit or metal sheathed (BX) wire to be in code?

Anything else I need to know that would be different than running a regular 120V 15A outlet?

Thanks!

Dave
 
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Old 07-19-16, 04:43 AM
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1) Is the barn attached to the house? If not, the subpanel grounds and neutrals must be separated and the grounding buss must be grounded to two 8' grounding rods, not pipe.

2) If the machine truly calls for 30 amps, then you must use 10 gauge wiring. What brand of saw is it? Odd that it would call for 30 amps at 240 volts.

3) As long as the cable is protected from damage you can run it provided your local code allows it. Some, like Chicago require conduit.
 
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Old 07-19-16, 09:13 AM
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My subpanel is connected to a ground wire that comes in from the main panel in the house. Should I also ground the subpanel box in the barn to a pipe or something nearby?
Do you have a separate ground bar in the subpanel. Is the neutral bar isolated?
Anything else I need to know that would be different than running a regular 120V 15A outlet?
As stated you would use 10-2 MM-b. The white by code would be remarked on both ends black or red or any color but white gray or green. This can be bands of colored tape or you can use a felt tip marker.
had an electrician update my subpanel in my barn to 240V.
I'm puzzled by that. If you had a subpanel it should already have been 120/240. If you originally had only a 120 volt feed to the barn and no subpanel that feed should have been disconnected when the subpanel was added.

Above assumes a detached barn.
 

Last edited by ray2047; 07-19-16 at 09:29 AM.
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Old 07-19-16, 09:45 AM
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Thanks for the responses...

I had an existing 120v sub panel in the detached barn with 30A service. I personally put in a new box for the 240v 60A service to replace it and then realized I needed to run a new cable from the house. The guy who then installed the new line put 2 240v breakers in the new box and ran a line to power the old subpanel so I didn't need to retro fit the existing barn circuits. Ideally I would have got a box big enough for the barn and just wired it all up in a single box.

i am not too knowledgable about the whole ground being isolated or not topic. I know that both subpanels do not have a ground wire to any kind of grounding device in the barn. As of now the neutral lines for both boxes are connected to the neutral coming from the main panel in the house.

I asked the electrician about this and he blew it off and said no grounding was needed at the sub panels since the ground connects to the main house.

So he is taking a short cut and I should learn how to properly ground a panel then? I assume this is something I should do but it's not critically dangerous just yet?
 
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Old 07-19-16, 09:49 AM
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Sorry u also asked if the neutral was isolated. It is connected to the main panel just like the hot and ground. Basically the subpanel in the barn is like a big outlet that is wired from a cable from the main house..
 
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Old 07-19-16, 10:03 AM
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The power feed from the house should be 4 wires (2 hots, 1 neutral, 1 ground). The neutrals and the grounds are bonded to the case and connected to the same bar at the main panel. The neutrals in the sub panel are to be isolated from the case and the grounds. The sub panel in the barn also is to have an electrode grounding system which can be two 8ft rods driven in the ground at the barn connected with #6 solid copper wire to the grounding bar in the sub panel. The equipment ground from the barn back to the house has a totally different purpose than the electrode grounding system.

Oh, and yes the electrician is not doing what is called for by the NEC.
 
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Old 07-19-16, 10:11 AM
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How many individual wires (conductors) do you have coming from the house to the barn? There should be a total of four, two "hots" a neutral (white) and an equipment ground (green or bare). At the house the neutral and equipment ground will connect to the neutral bus in the main (service) panel and the two hot wires connect to a 2-pole circuit breaker. At the barn the two hots connect to the main circuit breaker, the neutral to the isolated neutral bus and the equipment ground to a bonded (fastened directly to the metal enclosure) grounding bus.

This first panel in the barn must also have a local grounding electrode system consisting of at least one eight-foot long copper plated grounding electrode (ground rod) driven completely into the earth and connected with no less than #6 copper wire to the equipment grounding bus in the first (incoming power) panel. Some areas will require two grounding electrodes, connected together and spaced no less than six feet apart.

Posting some pictures of the various panels with the covers removed will help us to help you.

The machine specs:
- 240V single phase
- 23A Minimum Circuit Size
- 30A Connection
- L6-30 Power Cord
These specifications denote that a minimum of #10 copper conductors must be used in the circuit.
 
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Old 07-19-16, 01:25 PM
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Ok I think I got this thanks to this group and some fascinating reading on ecmweb.com on the differences between grounding and bonding. I also see that the slimy electrician who did the job didn't want to spend more time since it Involved more steps and a part he probably didn't have.

So the panel box I got at HD for 20 bucks said something about a separate kit that didn't come with it. I assume that is some kind of bar that connects the box to the ground from the main and to the ground in the barn circuits (not connected to neutral). I need to go buy that piece and install it in the new subpanel and then make sure all the grounds in the barn and conductive boxes are connected to it - and then to the ground from the main.

Then I have to do some research and learn how to install the 2 ground rods and connect those together and then to the subs new grounding bar.

If I don't do this then I'm nots protected from lightning or other stray voltages but I am protected from ground faults via the sub breakers or the main breaker.

Sound right?
 
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Old 07-19-16, 02:03 PM
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Yes, you almost always need to buy a separate ground and add it. All grounds including the ground wire from your house and the ground rods need to go to the ground bar. Only the neutrals including the neutral from the house go to the neutral bar which is isolated from the panel.
The guy who then installed the new line put 2 240v breakers in the new box
There should have been one 240 breaker for the saw and one or more 120 volt breakers for the 120 receptacles and lights in the barn. Did the cable he ran have a gray outer jacket? Did it have a white, black, red. and bare wire?
 
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Old 07-19-16, 02:42 PM
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I will also need a circuit for a jointer so he put in 2 240v circuits for me.

I'm pretty sure he used the correct cable. It's grey and very heavy and he ran it in pvc conduit. What I don't like is that near my house I have some bushes and he either ran out of time or the trencher wouldn't fit because the conduit is at the surface for about 5 feet or so. Kinda negates the hundreds of dollars he charged me to trench it in the first place. I assume the depth requirement is to prevent a gardener from inadvertently using a tool or device and hitting the wire by mistake - or is it more than that?

He also discovered I had another cable running out to the barn for a pair of lights that are switched at the house. For that he ran out and got direct burial cable for the 15A 120v line. He told me because of its lower voltage and amps it didn't need to be in conduit.

Lesson learned and next time I'll do it with an inspection...
 
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Old 07-19-16, 05:06 PM
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the conduit is at the surface for about 5 feet or so. Kinda negates the hundreds of dollars he charged me to trench it in the first place.
And is a code violation. He needs to come back and on his dime correct the code violation. Note he seems to have used conduit for the entire distance. Makes me wonder if he was licensed. Best practice is not to put cable in conduit except where it enters and leaves the ground. You normally use individual conductors in continuous conduit and direct bury cable.
He also discovered I had another cable running out to the barn for a pair of lights that are switched at the house. For that he ran out and got direct burial cable for the 15A 120v line. He told me because of its lower voltage and amps it didn't need to be in conduit.
B.S.! Proves he is no electrician. Both 120 and 240 can be direct buried. If those lights are on the outside that is okay. If they are inside the barn you probably have another code violation.
 
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Old 07-20-16, 11:01 AM
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I'm pretty sure he used the correct cable. It's grey and very heavy and he ran it in pvc conduit.
If that heavy cable has a gray outer sheathing and has Black, Red and White insulated conductors and a bare ground it is SER cable and you have another code violation. SER cable cannot be run underground at all, not in conduit and not direct buried. This guy is NOT a qualified electrician and should refund all of whatever you paid him. I am sure there were also no permits or inspections, another sign of a sure hack job.
 
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Old 07-20-16, 01:42 PM
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Joe, couldn't it also have been UF?
 
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Old 07-21-16, 03:44 PM
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Ray, maybe I was stretching a little, but I have seen so many hack jobs over the years and this sounds just like one. On the other hand, how many real electricians would attempt to pull UF cable in a buried PVC conduit. All the real electricians I know wouldn't even think of it.

I picture of that cable would tell us all a lot.
 
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Old 07-21-16, 04:09 PM
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how many real electricians would attempt to pull UF cable in a buried PVC conduit.
YES! That is why I wrote:
Makes me wonder if he was licensed
 
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Old 07-25-16, 11:58 AM
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Yes the guy was a total hack - weird because he has a storefront in town and specializes in generators and home audio. Not sure how you run around town installing generators and not be licensed electrician.

He didn't even bond the 2 subpanels together which is easy. So I took all ground wires and bonded them to the sub boxes and then to a pipe that isn't connected to a water line anymore but is burried plenty deep. Then wired up 2 hots to my outlet.

Pictures attached - look right ? Wrong?


Here is the picture...

http://i1376.photobucket.com/albums/...s5eizegkl.jpeg
 

Last edited by Drosner; 07-25-16 at 12:20 PM.
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Old 07-25-16, 12:03 PM
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Old 07-25-16, 03:10 PM
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That picture is most definitely wrong. I see two smaller conductors as well as the feeder conductors going to the main lugs. The feeder conductors MAY be smaller than the minimum size for those lugs. The "right-hand" feeder connection has been made to the neutral bus and the neutral feeder connection made to the right-hand bus. The white wire connected to the circuit breaker needs to be colored something other than white, gray or green.

Was this guy drunk or high when he did the work?
 
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Old 07-25-16, 03:16 PM
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Oh my god. Too much wrong. Grey cable if underground is wrong because it's SER. Double wires under main lugs, wrong. Neutral (white) to hot lug, wrong. Hot (red) to neutral lug, wrong. Black and Red are to be used as phase conductors. White is to be used as neutral. White where used as a phase conductor in a cable needs to be identified (taped) as red or black
 
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Old 07-25-16, 04:19 PM
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Thanks - I figured there was some wrong stuff in here.

One thing to mention which might explain the smaller connectors to the main lugs. This is the primary sub panel for the barn with 2 240v circuits. I have another panel that was existing with 2 120v circuits that was origally there.

So that we didn't need to redo the existing circuits he ran a #10 cable from the primary sub panel to power the secondary panel.

I installed the one 240v circuit today on the breaker. I forgot I needed to mark the white cable black since it carries a 120v hot to my 240v outlet.

Besides that and knowing the other cable is running to the second panel - what is left to resolve?

Here is the picture of the second panel...

http://i1376.photobucket.com/albums/ah19/david_rosner1/Mobile%20Uploads/image_zpse2tvdske.jpeg
 
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Old 07-25-16, 05:17 PM
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since it carries a 120v hot to my 240v outlet
No. There are no 120 volt hots. There are only the two legs of the 240 volts. One hot and a neutral make 120v but any wire connected to a breaker is 240 volts. That is why a white needs to be remarked as a hot.
 
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Old 07-25-16, 05:39 PM
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One thing to mention which might explain the smaller connectors to the main lugs. This is the primary sub panel for the barn with 2 240v circuits. I have another panel that was existing with 2 120v circuits that was origally there.
Doesn't matter, it is STILL wrong.

Besides that and knowing the other cable is running to the second panel - what is left to resolve?
Everything I mentioned in my previous post.
 
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Old 07-26-16, 06:34 PM
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Joe, couldn't it also have been UF?
Ray, I was right after all, a total hack job! The SER is obviously the cable this hack ran underground.

OP, is there no licensing requirement in your area....or state?

Yes the guy was a total hack - weird because he has a storefront in town and specializes in generators and home audio. Not sure how you run around town installing generators and not be licensed electrician.
Being licensed is not always a guarantee of a quality job. Sometimes qualifications and ethics don't mesh. Was there a permit for this job and was it inspected? The first sign of a non-licensed person claiming to be an electrician is doing work with no permit. I have seen similar work. I am aware of a company maybe 60 miles from my area that isn't licensed, but installs Generac generators all over this area. Generac lists them as a preferred installer and service provider on their website. I was even told Lowes uses this dude for generator installs.
 
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Old 07-26-16, 07:28 PM
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Wow, I hope you can find some recourse against this clown. I would need to look hard to find one thing that is correct.
 
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Old 07-27-16, 04:10 PM
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Appreciate the help gentlemen and would like to resolve and learn on this one. Can we try to tackle this one problem at a time...

1 - Right now the 2nd subpanel is connected via #10 wire from the 1st subpanel 2 main lugs (neutral/hot) to the 2nd subpanel neutral and hot bars. Sounds like the main neutral/hot (lugs?) should only be connected from the primary power source (main house panel in my case). So do i install a circuit breaker on the 1st subpanel and then run the line to the 2nd subpanel instead?

2 - Two of you both made comments about the "right hand feeder" and "neutral feeder" made to the right hand bus. Can you please explain this one as it looks right to me. The panel has 2 hot buses at the top and the neutral on the right side. From the main panel 2 hot lines go to the hot buses and the neutral (black and white in the picture) goes to the neutral bus - whats wrong here?

3 - i need to mark any white wires that are used to carry a hot with black tape - in my case that is only the single 240V circuit that i installed on the left hand double breaker. Do you see any other violations?

4 - how does the grounded connection look to this group? I have all of the bare ground wires connected together on the grounding bus on the lower left of the box and then connected to a buried unused water pipe. Look ok?


Thanks for the help - and yes i'll be going after the guy to resolve the wire run but i'd like to clean up the subpanels myself so i can learn how to do this properly.
 
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Old 07-28-16, 09:59 AM
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1 - Right now the 2nd subpanel is connected via #10 wire from the 1st subpanel 2 main lugs (neutral/hot) to the 2nd subpanel neutral and hot bars. Sounds like the main neutral/hot (lugs?) should only be connected from the primary power source (main house panel in my case).
Feeding a second subpanel from the first subpanel is fine except that at the first subpanel the feeder is double lugged in that panel's main lugs and neutral lug. The feeder neutral should be termoinated on the neutral bus and the feeders hot conductors should be terminated at a 2 pole 30 amp breaker.

So do i install a circuit breaker on the 1st subpanel and then run the line to the 2nd subpanel instead?
Yes, a 2 pole 30 amp breaker.

4 - how does the grounded connection look to this group? I have all of the bare ground wires connected together on the grounding bus on the lower left of the box and then connected to a buried unused water pipe. Look ok?
As far as I can tell from the picture it looks Ok.


You still have the issue of the feeder from the main panel to the first subpanel, it is definitely wrong.
 
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Old 07-28-16, 11:57 AM
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Since the feeder cable is not listed for use underground you really need to rip it out and start over.
 
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Old 07-28-16, 01:53 PM
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Will need to get the ser cable resolved but that will take some time.

Im clear now on how to properly connect the second sun panel.

What needs to be resolved on the feeder from the main to the subpanel outside of the SER cable?
 
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Old 07-28-16, 03:07 PM
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It needs to be four wires, two hots. one neutral one ground. If the conduit install is continuous and you can get the SE out you can pull in individual wires such as THWN, 2 black, 1 white, 1 green.
 
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Old 07-28-16, 05:47 PM
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Unless I am very much mistaken you have the "red" (red striped) incoming power connected to the neutral bus and the "white" (white striped) incoming neutral connected to the right-hand power lug. This is backwards, the white should connect to the neutral and the red to the power lug.

Also, while I cannot see for certain I suspect the green "bonding" screw in the neutral bus has NOT been removed as is required.
 
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Old 07-29-16, 11:22 AM
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Furd, I think you are right. I am not familiar with that little panel so didn't look really hard at it. I suspect that with some testing it'll be found that the jackleg non-electrician used the red as neutral.
 
 

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