Neutrals on ground bar

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mbrooke

mbrooke

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What code sections forbid the neutrals on ground bars in the main panel? Code book isn't in front of me. Also, would an isolated ground bar be ok as an add on neutral bar?
 
Look at 200.2 (B)

200.2 General. Grounded conductors shall comply with
200.2(A) and (B).


(A) Insulation. The grounded conductor, if insulated, shall
have insulation that is (1) suitable, other than color, for any
ungrounded conductor of the same circuit for systems of
1000 volts or less, or impedance grounded neutral systems
of over 1000 volts, or (2) rated not less than 600 volts for
solidly grounded neutral systems of over 1000 volts as described
in 250.184(A).


(B) Continuity. The continuity of a grounded conductor
shall not depend on a connection to a metallic enclosure,
raceway, or cable armor.
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If neutral current has to pass through the bonding screw, through the metal cabinet and then via the mounting screw holding the bar to the cabinet before getting to a branch circuit or feeder neutral conductor (or in reverse order - depending on how you want to look at it) - that is what is prohibited in 202(B). Only equipment grounding conductors can land on such a bar, but the main grounded conductor bus in the service equipment can have both grounded conductors and equipment grounding conductors connected to it.
 
I don't get why Iwire is saying its ok... unless there is a jumper wire between the ground and neutral bar... but that still doesn't make sense.
 
mbrooke said:
I don't get why Iwire is saying its ok... unless there is a jumper wire between the ground and neutral bar... but that still doesn't make sense.
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I think he is probably well aware of the rule here just maybe misunderstood specifically what you were asking about, misread what you said or something like that.
 
mbrooke said:
I don't get why Iwire is saying its ok... unless there is a jumper wire between the ground and neutral bar... but that still doesn't make sense.
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This is what is not prohibited by code........
mbrooke said:
What code sections forbid the neutrals on ground bars in the main panel? Code book isn't in front of me.
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This is what is prohibited by 200.2(B).......
Also, would an isolated ground bar be ok as an add on neutral bar?
Click to expand...
 
mbrooke said:
I don't get why Iwire is saying its ok... unless there is a jumper wire between the ground and neutral bar... but that still doesn't make sense.
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I could try to explain it but it is quicker to just admit I read your question wrong. :ashamed1: :)

That being the case I agree with the others.
 
iwire said:
I could try to explain it but it is quicker to just admit I read your question wrong. :ashamed1: :)

That being the case I agree with the others.
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Its ok. Ive read stuff wrong here more than once, more like every other thread :lol:

To be honest you got me thinking because I know you are a code expert. I actually thought you were right, and assumed that 200.2 (B) meant that the enclosure can not be the sole (depending entirely on it) conductor over to the neutral bar and assumed that a jumper would relieve that... but you have me in thought... could a large enough jumper allow for that loop hole?
 
mbrooke said:
Its ok. Ive read stuff wrong here more than once, more like every other thread :lol:

To be honest you got me thinking because I know you are a code expert. I actually thought you were right, and assumed that 200.2 (B) meant that the enclosure can not be the sole (depending entirely on it) conductor over to the neutral bar and assumed that a jumper would relieve that... but you have me in thought... could a large enough jumper allow for that loop hole?
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The enclosure can be a part of path for equipment grounding conductor, it can not be part of the path for the grounded (neutral) conductor. So if the only continuity between a particular bar (in a service equipment or first disconnecting means of SDS enclosure) and the incoming grounded conductor involves using the enclosure you can only land equipment grounding conductors on that bar.
 
mbrooke said:
Its ok. Ive read stuff wrong here more than once, more like every other thread :lol:

To be honest you got me thinking because I know you are a code expert. I actually thought you were right, and assumed that 200.2 (B) meant that the enclosure can not be the sole (depending entirely on it) conductor over to the neutral bar and assumed that a jumper would relieve that... but you have me in thought... could a large enough jumper allow for that loop hole?
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Yes you can use a proper sized wire for a jumper.
 
In a panel with the first means of disconnect when the neutral bus is full I have used a #4 bare jumper between the factory neutral bus & the added neutral bus. Maybe not to the letter of Code, but its always passed inspection.
 
kwired said:
but the main grounded conductor bus in the service equipment can have both grounded conductors and equipment grounding conductors connected to it.
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electrofelon said:
Can it? I think if you really look at the wording, this is not code complaint (although it is nearly universally accepted :angel:)
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I think you are mistaken. Why would the code specify no re-bonding past the load side of service disconnect if that were true?

(5) Load-Side Grounding Connections. A grounded conductor
shall not be connected to normally non?current carrying
metal parts of equipment, to equipment grounding
conductor(s), or be reconnected to ground on the load side
of the service disconnecting means except as otherwise permitted
in this article.
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And then there is this:

(4) Main Bonding Jumper as Wire or Busbar. Where the
main bonding jumper specified in 250.28 is a wire or busbar
and is installed from the grounded conductor terminal
bar or bus to the equipment grounding terminal bar or bus
in the service equipment, the grounding electrode conductor
shall be permitted to be connected to the equipment
grounding terminal, bar, or bus to which the main bonding
jumper is connected.
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If the GEC can land on the EGC bar why would you think an EGC couldn't land on the neutral bar? In the main service of course.



How do you see it as not code compliant?
 
electrofelon said:
Can it? I think if you really look at the wording, this is not code complaint (although it is nearly universally accepted :angel:)
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Which section do you claim disallows that?

Closest thing I can find though it doesn't really prohibit direct connection of EGC's to the grounded conductor bus/bar is 250.24 (B) for services or 250.30 (A)(1) for separately derived systems. Both basically say the
main bonding jumper / system bonding jumper shall be used to connect the equipment grounding conductor(s) and the service-disconnect enclosure / disconnecing means or source enclosure and/or the supply side bonding jumper to the grounded conductor. (those and's and or's depend on whether talking service or separately derived system)
 
I'm not aware of any code section that prohibits neutrals on the 'groundbar' (or vice versa) at the location of the main bonding jumper. Most service panels I see don't even have a separate groundbar installed. If they do then there's often a factory installed jumper bar, in which case I see no difference between the two bars. If there's an extra field installed groundbar then I agree it shouldn't have neutrals on it.
 
jaggedben said:
I'm not aware of any code section that prohibits neutrals on the groundbar (or vice versa) at the location of the main bonding jumper. Most service panels I see don't even have a separate groundbar installed. If they do then there needs to be a jumper directly between the bars, but often that is factory installed.
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The earlier quoted 200.2(B) does prohibit neutrals on ground bar that only relies on the enclosure for continuity to the grounded conductor - which is typical for most of your "loadcenters" with an insulated (but bond-able) neutral bus as well as a ground bus that is just bolted to the cabinet.
 
Little Bill said:
If the GEC can land on the EGC bar why would you think an EGC couldn't land on the neutral bar? In the main service of course.



How do you see it as not code compliant?
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In some scenarios the main bonding jumper is only required to be 12.5% of the phase conductors. Certainly the current for a neutral conductor connected to the EGC bus could exceed 12.5%.
 
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