Insualted Equipment Grounding Conductor

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mstrlucky74

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If spec read? Use insulated equipment grounding conductorfor all branch circuits and feeders? and you had a branch circuit being fedfrom a 3P 20A circuit breaker how manywire would you pull? Four? Thanks

Can't the conduit be used as a EGC?

 
mstrlucky74 said:
If spec read? Use insulated equipment grounding conductorfor all branch circuits and feeders? and you had a branch circuit being fedfrom a 3P 20A circuit breaker how manywire would you pull? Four? Thanks


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how many of the poles are actually in use? nothing says that all three poles have to be used.

is there a grounded conductor that needs a wire as well?
 
mstrlucky74 said:
Guys I'm lost. the conduit is RGS. Yes we need separate neutral per NEC and job spec.
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mstrlucky74 said:
Thanks Jim..so it's the 3 hots, 1N & 1 EGC? Can't the conduit be used as the EGC per the NEC?
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What is(are) the load(s). If the load(s) require a neutral, it's a fair indicator there is(are) line-to-neutral load(s). The NEC only requires a neutral if there are line-to-neutral loads.

If there is a spec for separate neutral, this usually indicates one for each line-to-neutral branch from panel to load.... but then the reason for using a 3-pole breaker comes into question...???
 
Smart $ said:
What is(are) the load(s). If the load(s) require a neutral, it's a fair indicator there is(are) line-to-neutral load(s). The NEC only requires a neutral if there are line-to-neutral loads.

If there is a spec for separate neutral, this usually indicates one for each line-to-neutral branch from panel to load.... but then the reason for using a 3-pole breaker comes into question...???
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Hey Smart$ thanks for the response.
They loads are lighting.
How would I know when I have a line to neutral load?
What is the other scenario, line to line loads? If so what would those be?
What do you mean exactly regarding the reason for the the 3pole breaker?
 
mstrlucky74 said:
Thanks Jim..so it's the 3 hots, 1N & 1 EGC? Can't the conduit be used as the EGC per the NEC?
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The NEC is the minimum design. The job specifications are more stringent, therefore they must be followed. You need to pull a 'green' grounding conductor.
 
mstrlucky74 said:
Hey Smart$ thanks for the response.
They loads are lighting.
How would I know when I have a line to neutral load?
What is the other scenario, line to line loads? If so what would those be?
What do you mean exactly regarding the reason for the the 3pole breaker?
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If the lighting is 120 or 277 volts then you have mine to neutral loads. If you use a MWBC (shared neutral) then you need a multi-pole CB or a handle tie for all CB's sharing a neutral. If the spec calls for a separate neutral condcutor with each circuit then all of your circuits will require 2 wires, and unless specified otherwise you could use one insulated EGC for all of the circuits in one raceway.
 
infinity said:
If the lighting is 120 or 277 volts then you have mine to neutral loads. If you use a MWBC (shared neutral) then you need a multi-pole CB or a handle tie for all CB's sharing a neutral. If the spec calls for a separate neutral condcutor with each circuit then all of your circuits will require 2 wires, and unless specified otherwise you could use one insulated EGC for all of the circuits in one raceway.
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Thanks Infinity. Aaaahhh so the 3 pole breaker can share a neutral cause if one circuit trips the outer two trip???? Regarding the EGC, Id I am pulling three circuits in a home run I can use just one EGC for those circuits? Where is that in th NEC? Thanks again?
 
mstrlucky74 said:
Thanks Infinity. Aaaahhh so the 3 pole breaker can share a neutral cause if one circuit trips the outer two trip???? Regarding the EGC, Id I am pulling three circuits in a home run I can use just one EGC for those circuits? Where is that in th NEC? Thanks again?
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Try 250.122(C)
 
mstrlucky74 said:
...so the 3 pole breaker can share a neutral cause if one circuit trips the outer two trip????...
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Yes, but two things come to mind.

A 3-pole breaker is typically common trip, and will act exactly as you've said: if one circuit trips, the other two will also be de-energized. This usually is not desired for lighting circuits. Preferred method is to use three (3) 1-pole, trip-indicating breakers with a 3-pole handle tie. This will usually allow only the faulting circuit to trip while the other two remain energized and some of the connected lighting to remain on. The investigating party will then have indication of which circuit tripped and have to de-energize the other two to reset the breakers (preferably resolve trip reason after de-energizing and before reset).

The second is if the spec's require a separate neutral for all line-to-neutral circuits, using a 3-pole breaker is overly expensive and serves no purpose. Using 3 handle-tied 1-pole breakers would also serve no purpose, but substantially less expensive. This leads me to believe the lighting circuit is 3? with lights wired line-to-line (1?) in a delta configuration.
 
Smart $ said:
Yes, but two things come to mind.

A 3-pole breaker is typically common trip, and will act exactly as you've said: if one circuit trips, the other two will also be de-energized. This usually is not desired for lighting circuits. Preferred method is to use three (3) 1-pole, trip-indicating breakers with a 3-pole handle tie. This will usually allow only the faulting circuit to trip while the other two remain energized and some of the connected lighting to remain on. The investigating party will then have indication of which circuit tripped and have to de-energize the other two to reset the breakers (preferably resolve trip reason after de-energizing and before reset).

The second is if the spec's require a separate neutral for all line-to-neutral circuits, using a 3-pole breaker is overly expensive and serves no purpose. Using 3 handle-tied 1-pole breakers would also serve no purpose, but substantially less expensive. This leads me to believe the lighting circuit is 3? with lights wired line-to-line (1?) in a delta configuration.
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thanks Smart. Spec does not indicate separate neutrals. It's def a 3p 20a breakers for all the lighting circuits ...
 
mstrlucky74 said:
thanks Smart. Spec does not indicate separate neutrals. It's def a 3p 20a breakers for all the lighting circuits ...
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If loads are line-to-line there'd be no need for a neutral and a 3-pole breaker would be required for a circuit wired as 3?.

If loads are line-to-neutral (MWBC), an RFI is in order to clarify which is required: 3-pole common-trip breaker or (3) 1-pole breakers with handle tie. IMO using a 3-pole breaker is a bad design practice for lighting MWBC's.
 
Smart $ said:
If loads are line-to-line there'd be no need for a neutral and a 3-pole breaker would be required.

If loads are line-to-neutral (MWBC), an RFI is in order to clarify which is required: 3-pole common-trip breaker or (3) 1-pole breakers with handle tie. IMO using a 3-pole breaker is a bad design practice for lighting MWBC's.
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Ok I'm confused as usual. As infinity stated they are line to neutral load...it is 277v lighting.
They are using a 3p common trip breaker for they lighting. There about 30 of these breakers......huge amount of lighting. Why is an RFI in order? The 3p breaker is what the engineer designed...whether you agree or not.


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mstrlucky74 said:
Ok I'm confused as usual. As infinity stated they are line to neutral load...it is 277v lighting.
They are using a 3p common trip breaker for they lighting. There about 30 of these breakers......huge amount of lighting. Why is an RFI in order? The 3p breaker is what the engineer designed...whether you agree or not.
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Okay, I didn't see where you actually stated line-to-neutral loads. Infinity said "if". But now you've clarified it is in fact 277V lighting.

I understand... engineer designed with 3-pole common-trip breakers. It amounts to roughly 3-times the lighting going dark on trip. It's up to you whether you seek clarification. Doesn't bother me any either way. ;)
 
Smart $ said:
Okay, I didn't see where you actually stated line-to-neutral loads. Infinity said "if". But now you've clarified it is in fact 277V lighting.

I understand... engineer designed with 3-pole common-trip breakers. It amounts to roughly 3-times the lighting going dark on trip. It's up to you whether you seek clarification. Doesn't bother me any either way. ;)
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It also has the advantage that the 3-pole breakers are more expensive than 3 1-pole breakers and 1 3-pole handle tie.:p
 
Smart $ said:
Okay, I didn't see where you actually stated line-to-neutral loads. Infinity said "if". But now you've clarified it is in fact 277V lighting.

I understand... engineer designed with 3-pole common-trip breakers. It amounts to roughly 3-times the lighting going dark on trip. It's up to you whether you seek clarification. Doesn't bother me any either way. ;)
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Thats a good point. Thanks for the help Smart.
 
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