Neutral wire on ground bus bar. Safe or not?

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Old 10-03-20, 08:34 AM
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Neutral wire on ground bus bar. Safe or not?

I often see neutral wire on ground bus bar secured to the chaises.
In my opinion, this is not safe because bonding screw is only path the neutral and the current will flow through steel chaises. Yet, local county inspectors seem to be ok with that (never seen one failing for this).

Is there any code regarding this case?
 

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10-03-20, 10:15 AM
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A bus bar bolted or screwed into the pan is only for ground use.
The neutral wires must go to a bar that is physically connected to the main neutral wire.
 
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Old 10-03-20, 10:04 AM
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OK only if this is the main panel (service disconnect) and the panel label states that neutrals are allowed on grounding bar. There are some boxes that have a strap connecting the two bars so either can be used for neutral or ground. Otherwise you are correct as the chassis is not be be part of the normal current flow.
 
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Old 10-03-20, 10:08 AM
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Bus bars connected with a strap are technically both neutral bus bars. It is just ground wires can be connected to neutral bus bar in main panel. Aren't they?

 
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Old 10-03-20, 10:15 AM
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A bus bar bolted or screwed into the pan is only for ground use.
The neutral wires must go to a bar that is physically connected to the main neutral wire.
 
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Old 10-03-20, 01:41 PM
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This should be the relevant NEC section. Keep in mind "grounded" is their word for neutral.

200.2(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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Old 10-03-20, 01:52 PM
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I doubt any panel manufacturer approves of this. The bonding screw is only for carrying fault current, not operating current.

The reverse, connecting grounding wire to neutral bus in main panel, is technically OK but a terrible practice.
 
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Old 10-03-20, 01:58 PM
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The bonding screw is only for carrying fault current, not operating current.
100% correct.

The reverse, connecting grounding wire to neutral bus in main panel, is technically OK but a terrible practice.
Why a terrible practice ? Some main panels only have one neutral bar and then the neutrals and grounds all connect to the same bar. Nothing wrong with that.

 
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Old 10-03-20, 02:46 PM
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"Why a terrible practice ? Some main panels only have one neutral bar and then the neutrals and grounds all connect to the same bar. Nothing wrong with that."

Sooner or later you'll run out of neutral bar space, so better to use grounding bars from the start.
 
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Old 10-03-20, 03:26 PM
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200.2(B) Continuity. The continuity of a grounded conductor
shall not depend on a connection to a metallic enclosure,
raceway, or cable armor.
This is what I was looking for.

For some reason I see neutral wire connected to ground bus bar very often and never seen a inspector catching this. The electrician who worked on the panel says it passes inspection so all is good.
 
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Old 10-03-20, 04:48 PM
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Sooner or later you'll run out of neutral bar space, so better to use grounding bars from the start.
That's not the point.

It is very possible that an inspector could miss a neutral wire in a dedicated ground block.
A licensed electrician should know better.
 
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