Need help wiring my subpanel...

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  #1  
Old 11-16-13, 02:05 PM
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Need help wiring my subpanel...

FIRST:

This is how it is currently installed. Long story short, a licensed electrician put it in and wired it off of ONE of my main panels (I have 2 200A). All im doing is putting it off of my first main panel.

This is how it is installed now.



Feed from the panel comes from below. I want to check that this is setup correctly with the neutral/ground. It doesnt look right and I want to make sure it is or is not and what to do. The subpanel is in the same building.

SECOND:

I have 6AWG THHN wire in conduit running from the panel I want to use. It is on a 50A breaker. In my main panel I hooked the white to the neutral bar where the others are, and the green wire to the ground bar. Then I put the red and black off of each lug on the 50A breaker.

Does it matter which lug the red or black go on?

Does it matter which terminal in the subpanel the red and black are wired to to feed it?
 
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  #2  
Old 11-16-13, 02:52 PM
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I do not see a ground wire going to the panel or a bonded ground bar in the panel. I'd almost bet the neutral bar isn't isolated and it should be. If the conduit is metal and continuous you don't need the ground wire but you do need the ground bar. Those ground wires are not suposed to be on the neutral bar.

What size is the breaker feeding the pictured panel? What size are the wires?
 
  #3  
Old 11-16-13, 03:13 PM
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The wires feeding it are 8ga, but im going to replace those with 6ga in smurf conduit. It is fed with a 50A breaker but I have a 60A if I want.

The way its currently wired is the ground from the main panel is on the neutral bar with all those white wires and all of the other ground wires. The neutral bar is on the black plastic bracket, and so far as I can tell is NOT touching the subpanel anywhere, so it IS in fact isolated I believe.

WHY is this wrong? This was a licensed electrician (can you tell why i second guess EVERYTHING), is it dangerous?


So....I need a ground bar. SCrew that to the case of the subpanel. Put the ground wire from the main pannel to the ground bar as well as all of the other circuit grounds. Then, put all the white wires on the neutral bar (which is isolated)??
 

Last edited by agdodge4x4; 11-16-13 at 03:44 PM.
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Old 11-16-13, 04:28 PM
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WHY is this wrong? This was a licensed electrician (can you tell why i second guess EVERYTHING), is it dangerous?
#8 on a 50 amp breaker is a fire hazard. Not having ground bonded and neutral isolated after the first OCPD is a shock hazard.

So....I need a ground bar. SCrew that to the case of the subpanel. Put the ground wire from the main panel to the ground bar as well as all of the other circuit grounds.
That is correct.

Then, put all the white wires on the neutral bar (which is isolated)??
If he installed the green bonding screw or left a bonding strap in place it is not isolated. Always best to further verify isolation with a meter.
 
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Old 11-16-13, 04:30 PM
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Side question - Are you sure a 50 amp feed is enough? Looks like you are planning 4x 50amp 240v loads.
 
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Old 11-16-13, 04:33 PM
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#8 on a 50 amp breaker is a fire hazard.
This is precisely why I am using 6AWG THHN. This electrician INSISTED that it was totally legal on romex wire because it is 'residential'. I think he's full of crap and Im fixing it. He put all my 8ga romex on 50A breakers. Fortunately, the appliances they serve only require 40A, so its just a breaker swap. I want 50A or 60A safely to the sub panel. Its on a 50A now, but I can do 60A legally with 6g THHN in conduit?

There is no bonding screw or strap. Ill take another pic. If the neutral is in fact isolated, then I can simply install the ground bar to the subpanel and put the ground from the main on it, along with all the other grounds and then put all the neutrals, including the one from the main panel on the isolated neutral bar...do I understand that correctly?


Side question - Are you sure a 50 amp feed is enough? Looks like you are planning 4x 50amp 240v loads.
No. Im not planning that at all. Thats what the electrician wired in. Im reapportioning the subpanel to supply lighting and outlets only. The load calcs support up to 4000 square feet on this subpanel with 50A....Im doing less than half of that.
 
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Old 11-16-13, 05:11 PM
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To clarify my statement. In some cases of individual wires not cable going very short distances between panels you can use one size smaller. I don't think that applies to cable but the pros will have to answer that.
 
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Old 11-16-13, 05:17 PM
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Meh....it doesnt matter. If I use a 50A breaker on 6g THHN its code compliant if in conduit.

Back to the subpanel.

How do I test to make SURE the neutral is isolated from the panel and ground with a multimeter?

Also, does it matter which wire (black or red) goes to which terminal in the sub panel?
 
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Old 11-16-13, 06:22 PM
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How do I test to make SURE the neutral is isolated from the panel and ground with a multimeter?
Set your meter to lowest ohms scale. With power off and neutrals disconnected measure from neutral bus to the metal case where there is no paint. Infinity it is isolated. Continuity it isn't isolated.
 
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Old 11-16-13, 06:26 PM
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OK. I will check. If it IS isolated, then I can proceed as follows?:

I need a ground bar. SCrew that to the case of the subpanel. Put the ground wire from the main pannel to the ground bar as well as all of the other circuit grounds. Then, put all the white wires on the neutral bar (which is isolated)??
 
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Old 11-16-13, 07:41 PM
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Long story short, a licensed electrician put it in and wired it off of ONE of my main panels (I have 2 200A).
Did he just have a business license or was he licensed by the state? I think Texas does license individual electricians. Isn't that right Ray?
 
  #12  
Old 11-16-13, 09:44 PM
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I have no idea what kind of license he has, its a shop with a labor pool and probably a few actual electricians. All are licensed...in whatever form they are. I mean, I can understand a person like myself opening the main panel, seeing ground and neutral bonded, and duplicating it in a subpanel. But an experienced electrician should know better than I do about electrical current. It seems to me its a shock hazard if you were to touch the metal sub panel, which is IN the living space. Kids could walk up and touch it and if everything wasnt kosher, they could be shocked.
 

Last edited by agdodge4x4; 11-16-13 at 10:08 PM.
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Old 11-17-13, 06:04 AM
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I think Texas does license individual electricians. Isn't that right Ray?i
In the county not much oversight. It is mostly city regulation. No city minimal regulation. Even in the city I have seen jobs done by third world electricians working under a city licensed master. (Would you believe a hot and neutral on a circuit from different meters on different drops?)
 
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Old 11-17-13, 06:34 AM
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While the person that installed your sub-panel may have been licensed, it likely was not a journeyman/master electrical license based on what I see, and from your description. Perhaps it was a low voltage electrical.

Your panel neutral does not look isolated, or the grounds are in the wrong bus. This is a hazard because you will have current on the ground wire of the feeder going back to the main panel.

This electrician INSISTED that it was totally legal on romex wire because it is 'residential'. I think he's full of crap and Im fixing it. He put all my 8ga romex on 50A breakers
He's full of crap for sure! #8 Romex is only rated for 40 amps.

I want 50A or 60A safely to the sub panel. Its on a 50A now, but I can do 60A legally with 6g THHN in conduit?
#6 Individual THHN wire installed in a raceway (ENT for example) has a rating as high as 65 amps (which you can go up to the next breaker size so 70) based on the terminations of the circuit breakers (75 degree) Be sure to pull a ground wire as well.
 
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Old 11-17-13, 07:27 AM
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In the county not much oversight. It is mostly city regulation. No city minimal regulation. Even in the city I have seen jobs done by third world electricians working under a city licensed master. (Would you believe a hot and neutral on a circuit from different meters on different drops?)
It's similar to that here too, but I know a lot of states individually license each and every electrician in their state. I'm not sure there is a perfect system.
 
  #16  
Old 11-18-13, 07:55 AM
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Your panel neutral does not look isolated, or the grounds are in the wrong bus. This is a hazard because you will have current on the ground wire of the feeder going back to the main panel.

Read more: http://www.doityourself.com/forum/el...#ixzz2l0d3fbIY
The neutral pretty much HAS to be isolated. There is no green bonding screw installed and the neutral is on a black plastic standoff. I will verify with my volt meter before completing the wiring, but even now, Im certain it is an isolated neutral.
 
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Old 11-18-13, 08:16 AM
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The neutral pretty much HAS to be isolated. There is no green bonding screw installed and the neutral is on a black plastic standoff. I will verify with my volt meter before completing the wiring, but even now, Im certain it is an isolated neutral.
It serves little purpose for the panel neutral to be isolated from the panel box when the equipment grounding conductors from the branch circuits are terminated on the neutral bar instead of on a properly installed ground bar. I see a grounding conductor in the NM cable feeding the subpanel, but cannot see where it is terminated. I suspect it is also terminated on the neutral bar instead of on a ground bar.
 
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Old 11-18-13, 08:20 AM
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There is no green bonding screw
Which in a twisted way is another mistake by your electrician. While the neutral and ground should have been separated under modern code if he was following old cold and combining neutral and ground the neutral bar should have been bonded. {shakes head}
 
  #19  
Old 11-18-13, 08:23 AM
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It serves little purpose for the panel neutral to be isolated from the panel box when the equipment grounding conductors from the branch circuits are terminated on the neutral bar instead of on a properly installed ground bar. I see a grounding conductor in the NM cable feeding the subpanel, but cannot see where it is terminated. I suspect it is also terminated on the neutral bar instead of on a ground bar.

Read more: http://www.doityourself.com/forum/el...#ixzz2l0k9afzs

Just to be clear: All grounds and all neutrals are bonded to the neutral bar which is NOT bonded to the panel.

My plan here is to go to my favorite box store and buy a ground bar for all of about 6 bucks and install it. Then, with the neutral and ground bar isolated from each other, install all of the grounds on the ground bar and all of the neutrals on the neutral bar and enjoy the new subpanel.
 
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Old 11-18-13, 09:17 AM
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Yes, that is the proper way to do it.
 
  #21  
Old 11-25-13, 06:39 PM
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Ground bar installed, neutral totally isolated. Sub panel is now served with 6ga THHN in proper conduit. Its on a 50A breaker, but Im going to bump that up to 60A because I need that 50A breaker in another location. I have all of my second floor lighting run off the sub panel now.
 
  #22  
Old 11-25-13, 08:30 PM
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Excellent! Thanks for letting us know the outcome.
 
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