Is this considered a Sub-Panel or Not?

[iwire]

Re: Is this considered a Sub-Panel or Not?

Originally posted by suemarkp:
All installations that have a metal conduit between the meter and the main panel have a conduit that is paralleled with the neutral

Yes, do you think it is a good idea?

With the conduit carrying current a loose fitting could result in a fire.

 

[suemarkp]

Re: Is this considered a Sub-Panel or Not?

Yes, it could, but I would also expect there to be very visible signs of a problem (dimming lights) if the neutral was also degraded. If the neutral is fine, then the majority of current would take that path. This is also service equipment so you've got everything bonded on both ends with bushings or double locknuts.

I thought the worse problem was when the neutral came loose and your service conduits become the sole path for neutral current. This works until things are heavily loaded, because the bonding conductor requirements are much smaller than the normal current carrying requirements. So you eventually overheat your bonding wires and then you have a very visible problem with flickering lights (and a fire hazard).

Aren't most commercial/industrial services still installed in all metal conduit? In taking a look at residential services, it seems to be maybe 70/30 PVC -vs- metal nowdays, but I thought that was because of cost and not performance.

 

[iwire]

Re: Is this considered a Sub-Panel or Not?

I agree with you for the most part, I just choose to avoid having the conduits carry any current if at all possible.

No question about it, there are thousands of services working fine with metal conduit between the meter and main.

I have taken to using PVC nipples between the meter or CT enclosure and the service disconnect enclosure.

That also eliminates bonding issues.

 

[volt101]

Re: Is this considered a Sub-Panel or Not?

If 250.24 A 1 doesn't apply because of the fact that the conductor would normally be un-insulated, then It would not be allowed because of the definition of:

Grounding Conductor, Equipment. The conductor used to connect the non?current-carrying metal parts of equipment, raceways, and other enclosures to the system grounded conductor, the grounding electrode conductor, or both, at the service equipment or at the source of a separately derived system.

You would be using it as a current carrying conductor.

Not to mention that 200.2 indicates that we can have un-insulated grounded conductors.

250.24(5) A grounding connection shall not be made to any grounded conductor on the load side of the service disconnecting means except as otherwise permitted in this article.

Besides, what is the limit on these extensions? Through the garage and down inside of the basement? It would, however, make bonding/grounding a lot easier!

 

[suemarkp]

Re: Is this considered a Sub-Panel or Not?

Originally posted by iwire:
[QB] I agree with you for the most part, I just choose to avoid having the conduits carry any current if at all possible.

Can't argue with that. When I did my 400A service, I think it would have been better to do it in PVC instead of RMC. It would have made the multiple cutting and rethreading of nipples much easier (got to learn to measure twice and cut once) plus I'd have the benefit of knowing if a neutral came loose. As I recall though, finding sch 80 PCV was rather difficult at the time (I shop the DIY stores whenever possible after getting reamed for $95 at an EC store for a 3" RMC compression coupling). Now, even Home Depot carries sch80 RNC.

 

[allenwayne]

Re: Is this considered a Sub-Panel or Not?

I can`t agree more go with nmrc no mig busings,no bonding jumpers, just a piece of pvc lock nuts and bushings. and if the helper cut it a bit sh ort the glule streches that pvc

 

[LarryFine]

Re: Is this considered a Sub-Panel or Not?

I'd have to agree that even a close-nippled panel should be considered a sub-panel, just as one would with main disconnects back-to-back with main-lug panels.

That the main disconnect enclosure also contains branch circuits doesn't change that.

Besides, most commercial/industrial panels I'm familiar with are set up for seprate neutrals and grounds already; we're just talking about not bonding the neutral to the cabinet.

 

[LarryFine]

Re: Is this considered a Sub-Panel or Not?

Originally posted by infinity:
Main outside = 4 conductors
Main inside = 3 conductors

In other words, your installation requires separate neutral and grounding conductors, and grounding electrodes land outside, in the main-disconnect box.

 

[ronaldrc]

Re: Is this considered a Sub-Panel or Not?

Roger his is not the thread I was talking about but it fits fine.

Cramp like this is the reason most people in this trade burn out every 12 or so years after being in the trade.

Myself I have burned out at least three times.

This is the most debatable subject, other than grounding I guess that is argued about in the trade and very confusing.

The thread I was talking about the main was more like 35 ft. from the indoor panel thats why I got a kick when you called them buss extensions instead of conductors I know your statement was in fun.

But really wouldn't the answer depend on where you are bonding your neutral and grounding electrode conductors together?

Since the NEC says bond as close to the main as possible I think the load center should be treated as a sub panel with a four wire feeder.

But if the inspector allows you to bond them in the load center and take your grounding electrode conductor to the electrode from the load center to the electrode then you would need three conductors two hot and a neutral from the main outside too the load center in side.

If you bond the neutral and ground together in the main outside then from that point on you should separate your neutral and ground.And you would need two hots one neutral and Equipment grounding conductor.

If I am repeating what someone else has already said I apologize and agree with you.

Ronald

 

[roger]

Re: Is this considered a Sub-Panel or Not?

Good morning Ronald, I think THIS is the thread you are talking about.

Roger

 

[ronaldrc]

Re: Is this considered a Sub-Panel or Not?

Roger appreciate you digging that out I couldn't find it.

That was a good discussion on the subject I thought.

Are they still buss extension?

 

[roger]

Re: Is this considered a Sub-Panel or Not?

Originally posted by ronaldrc:
Roger appreciate you digging that out I couldn't find it.

You're welcome Ronald.

That was a good discussion on the subject I thought.

I thought is was too.

Are they still buss extension?

Well, it might take some more discussion to come to a conclusion.

Roger