Grounding/neutral at sub panel?

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robert pitre

robert pitre

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Houma,la
In a sub panel I see were there is a metal bar that runs across from the grounding side to the neutral side, this bar needs to be remove as my under standing, is this correct?:?
 
Most likely it should be removed but hard to say for sure from the info provided.

For instance where is this subpanel?
 
Yes In a sub panel neutrals & grounds need to be landed on their own neutral/ ground bar. Some times separation is easy, just remove the Green bonding screw. In your case remove the neutral/ground tie bar. When you remove this tie bar you need to assure that the bar used for your grounds is bonded to the panel enclosure.
 
iwire said:
I mean is the subpanel in a detached / separate building of structure from the first means of disconnect?
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Drawing a simple wiring diagram may clarify it.
At me end draw a device entrance with the N and EGC connected together. The draw two parallel lines connecting them together at the farther end. Now visualize a line to neutral load when the neutral current is now shared by the EGC.
If the neutral is grounded at the SE of then somewhere down the line you bond the neutral to the EGC again then you have provided a path for the neutral current to travel a parallel path back to the SE. Consider that grounding prong in a grounded tool or appliance that plugs into the EGC. Would it be a good idea to have a neutral current using the EGC to return to the SE? I think not and it provided and opportunity for an electric shock should you come into contact with the tool or appliance.
Bottom line? You certainly don't want any neutral current to use the EGC as a return path to the SE.
 
templdl said:
Drawing a simple wiring diagram may clarify it.
At me end draw a device entrance with the N and EGC connected together. The draw two parallel lines connecting them together at the farther end. Now visualize a line to neutral load when the neutral current is now shared by the EGC.
If the neutral is grounded at the SE of then somewhere down the line you bond the neutral to the EGC again then you have provided a path for the neutral current to travel a parallel path back to the SE. Consider that grounding prong in a grounded tool or appliance that plugs into the EGC. Would it be a good idea to have a neutral current using the EGC to return to the SE? I think not and it provided and opportunity for an electric shock should you come into contact with the tool or appliance.
Bottom line? You certainly don't want any neutral current to use the EGC as a return path to the SE.
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Bottom line, code wise, safety wise if the OPs subpanel is at a separate building or structure it may be necessary to leave the neutral bonded to the EGCs.

We don't yet have enough info to recommend lifting this bond.
 
iwire said:
Bottom line, code wise, safety wise if the OPs subpanel is at a separate building or structure it may be necessary to leave the neutral bonded to the EGCs.

We don't yet have enough info to recommend lifting this bond.
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Yes, I see now as it is only highly restricted conditions such as:
No equipment grounding conductors can be run in the supply feeder
There must be no continuous metalic paths bonding the grounding systermms on both buildings together
There must be no GF equipment installed at the first service.
 
Don't remove the bar between the two. Just add a ground bar with more than the necessary number of terminals for the grounds. Then move all the grounds there, make sure it's bonded to the box and the egc coming from the feeder.
 
jaylectricity said:
Don't remove the bar between the two. Just add a ground bar with more than the necessary number of terminals for the grounds. Then move all the grounds there, make sure it's bonded to the box and the egc coming from the feeder.
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Since you are adding a ground bar which is screwed directly to the panel have you addressed that bonding screw that is still present that is still bonding the now neutral bar to the box?
 
templdl said:
Since you are adding a ground bar which is screwed directly to the panel have you addressed that bonding screw that is still present that is still bonding the now neutral bar to the box?
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We don't know if there's a bonding screw, actually. OP hasn't told us as much. Frankly, the use of "neutral side and ground side" leads me to believe OP just thinks that the neutral bar on the left is different than the neutral bar on the right. And also OP leads me to believe he might be installing this new, in which case the bonding screw/strap or whatever hasn't even been installed yet.
 
jaylectricity said:
We don't know if there's a bonding screw, actually. OP hasn't told us as much. Frankly, the use of "neutral side and ground side" leads me to believe OP just thinks that the neutral bar on the left is different than the neutral bar on the right. And also OP leads me to believe he might be installing this new, in which case the bonding screw/strap or whatever hasn't even been installed yet.
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And the beat goes on, let's all take a guess and what the OP has. He"miight be" etc. It bothers me that quite often it appears as though we are handing someone a loaded gun. It would be interesting to know if a panel is offered with an neutral bar with no bonding scew installed of provided for bonding. I would like to think that there was but without being specific kit is to be questioned.
Oh well.
 
templdl said:
It would be interesting to know if a panel is offered with an neutral bar with no bonding scew installed of provided for bonding. I would like to think that there was but without being specific kit is to be questioned.
Oh well.
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Many panels come without the bonding screw installed, it is usually in the box loose in a small plastic bag. Even if it was preinstalled, code requires it to have a green finish so it is easily recognized.
 
First off, does that metal bar between the neutral strips happen to run behind the buss bar assembly?
If so, it is mechanically attached to the panel enclosure which makes this panel "suitable only as service equipment" instead of the more available panels now a days that are "suitable for use as service equipment" which will allow the neutrals and grounds to be separated if used as a sub-panel.
 
mopowr steve said:
First off, does that metal bar between the neutral strips happen to run behind the buss bar assembly?
If so, it is mechanically attached to the panel enclosure which makes this panel "suitable only as service equipment"....
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That is not always so. Cutler Hammer BR has a neutral bar that runs behind the buss but it is isolated unless you bond it to the can.
 
ActionDave said:
That is not always so. Cutler Hammer BR has a neutral bar that runs behind the buss but it is isolated unless you bond it to the can.
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Sorry, I should have said "look to see if the bar between the neutral buss bars is in contact with enclosure".
I was just going from a recent job where I noticed the difference between ( suitable only for service equipment and the other. It sparked my awareness as I was trying to pull a new feeder to what was actually a sub panel in an existing install and saw there is no way to seperate the grounds and neutrals unless I would install isolated neutral bars.
 
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