Can a steel plate be used as a current carrying bus bar?

[Jamesco]

If the CT cabinet is on POCO side of the "service point" then NEC doesn't apply to it and it is definitely not your problem what is inside there.

But the cabinet, enclosure, still has to be bonded to the grounded conductor.
250.92 (A) and 250.92 (A) (2)?

250.92 (A)(2)

All enclosures containing service conductors including meter fittings, boxes, or the like, interposed in the service raceway or armor.

That means the CT enclosure too, the way I read it.

The POCO only owns the CTs, and the padlock on the doors. The customer owns the CT cabinet (enclosure), service entrance conductors riser, mast, conduit(s) and the service conductors. Improper bonding of the service enclosure (CT cabinet) to the grounded conductor could cause an electrical shock hazard in the event of an ungrouned phase conductor to ground fault. The improper bonding could also cause extensive damage to the supply side service conductors as well the enclosure and raceway/fittings. In this case 3" Emt and connector(s).

Add to that one end of the supply side conductors (Main Disconnect enclosure) raceway(s) is improperly bonded to the grounded conductor.

Question is, how long would it take for a phase to enclosure and or raceway fitting ground fault to blow the High Line fuse(s) at the utility pole? The quicker the ground fault is cleared, the less the damage to equipment and wiring. The more series impedance (poor continuity bonding connections) in the ground fault circuit the slower the response time. Slower response time translates into more damage.

Will this #8 truss head SMS be able to handle possibly thousands of amps until the High Line Fuse(s) blow?

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And,... the electrician didn't even take the time to remove the paint from the main switch enclosure where he bonded the bonding strap to the enclosure. What's the odds the #8 SMS will blow before the High Line Fuse(s) at the utility pole?

If the supply side bonding is done per code approximately how many thousands amps could flow in the ground fault circuit before the High Line fuse(s) blow at the utility pole? I know there are a lot of factors that have to be imputed into the equation. Just give an approximate number. Service is a 120/208V 3ph 4w 600 amp. POCO lateral is two parallel quadplex. Size of wire? Length from 3 transformers, at pole, to service mast weatherheads is approximately 35ft maybe 45ft max.

 

[Jamesco]

EDIT:

Service is a 120/208V 3ph 4w 600 amp. POCO lateral is two parallel quadplex. Size of wire? Length from 3 transformers, at pole, to service mast weatherheads is approximately 35ft maybe 45ft max.

Service entrance conductors are parallel 500 AL.

 

[kwired]

Just further validation for me after an AHJ electrical inspector told me I was wrong in my reading of 250.92 (B).

Paul Abernathy is one of the members of the CMP #5. Jmho, he is qualified to explain the meaning of 250.92 (A) and (B). I think he did a great job in his presentation on the subject matter.

He basically has no more or less credibilit than someone like Mike Holt though. Yes he has knowledge and experience, and it on a CMP which maybe makes him have more credibility on discussions involving content that CMP is responsible for.

Any comment he makes is not an official interpretation as far as NFPA would be concerned, though he possibly could be involved in making such an interpretation but would be representing NFPA in that particular process.

You could give said "private explanation" to your inspector, they are still free to choose whether they accept that explanation or not, in fact they are free to choose any NFPA interpretation or not, though if it is genuine NFPA interpretation they may be more likely to accept it. Otherwise all they likey have on law books is the NFPA70 and which year and possibly some their own amendments to it.

 

[kwired]

But the cabinet, enclosure, still has to be bonded to the grounded conductor.
250.92 (A) and 250.92 (A) (2)?

250.92 (A)(2)

That means the CT enclosure too, the way I read it.

The POCO only owns the CTs, and the padlock on the doors. The customer owns the CT cabinet (enclosure), service entrance conductors riser, mast, conduit(s) and the service conductors. Improper bonding of the service enclosure (CT cabinet) to the grounded conductor could cause an electrical shock hazard in the event of an ungrouned phase conductor to ground fault. The improper bonding could also cause extensive damage to the supply side service conductors as well the enclosure and raceway/fittings. In this case 3" Emt and connector(s).

Add to that one end of the supply side conductors (Main Disconnect enclosure) raceway(s) is improperly bonded to the grounded conductor.

Question is, how long would it take for a phase to enclosure and or raceway fitting ground fault to blow the High Line fuse(s) at the utility pole? The quicker the ground fault is cleared, the less the damage to equipment and wiring. The more series impedance (poor continuity bonding connections) in the ground fault circuit the slower the response time. Slower response time translates into more damage.

Will this #8 truss head SMS be able to handle possibly thousands of amps until the High Line Fuse(s) blow?

Everbilt #8 x 1/2 in. Phillips Modified Truss Head Zinc Plated Sheet Metal Screw (4-Pack) 815341 - The Home Depot

Provide the best and essential addition to your fastening application by selecting this affordable Zinc-Plated Wafer Head Phillips Drive Drywall Screw.

www.homedepot.com

And,... the electrician didn't even take the time to remove the paint from the main switch enclosure where he bonded the bonding strap to the enclosure. What's the odds the #8 SMS will blow before the High Line Fuse(s) at the utility pole?

If the supply side bonding is done per code approximately how many thousands amps could flow in the ground fault circuit before the High Line fuse(s) blow at the utility pole? I know there are a lot of factors that have to be imputed into the equation. Just give an approximate number. Service is a 120/208V 3ph 4w 600 amp. POCO lateral is two parallel quadplex. Size of wire? Length from 3 transformers, at pole, to service mast weatherheads is approximately 35ft maybe 45ft max.

See definition in art 100 of service point, and the informational note that follows. Informational note is not part of code but does help explain things some.

That definition says nothing about ownership, many cases a client must pay for items even if the POCO still operates and maintains it down the road.

Bottom line is which side of the service point is the CT cabinet on?

Here it is usually POCO supplied or POCO specified, though they take care of what is inside. Usually incoming conductors and internal equipment is POCO side of the service point, and outgoing conductors are customer side the service point, regardless of who paid for the CT cabinet itself.

 

[kwired]

There can be cases where customer/contractor buries conduit installs vaults, cabinets, etc. and installed to specifications made by POCO. Yet POCO maybe pulls conductors to some or all those components and takes over maintenance from there on. Often times those kind of items are considered on POCO side of the service point and are not subject to NEC.

 

[Jamesco]

See definition in art 100 of service point, and the informational note that follows. Informational note is not part of code but does help explain things some.

That definition says nothing about ownership, many cases a client must pay for items even if the POCO still operates and maintains it down the road.

Bottom line is which side of the service point is the CT cabinet on?

Here it is usually POCO supplied or POCO specified, though they take care of what is inside. Usually incoming conductors and internal equipment is POCO side of the service point, and outgoing conductors are customer side the service point, regardless of who paid for the CT cabinet itself.

Art 100

Service Point. The point of connection between the facilities of the serving utility and the premises wiring.

Point of attachment, connection, to the customer's service entrance conductors.

That definition says nothing about ownership,

It's implied, premises wiring. Therein the customer's wiring.

many cases a client must pay for items even if the POCO still operates and maintains it down the road.

Not in the metro or surrounding cities here. Power company owns the CTs, padlock, and meter. POCO is responsible for maintaining such. Customer owns and is responsible for maintaining everything else from the point of attachment.

When you get into rural areas of the State Utility Power Co ops rules can be and are different.

I should clarify what I said in an earlier post about bonding the neutral block in the CT cabinet to the enclosure. That could only be done with the permission of the POCO. To be honest because of the energized live parts inside the cabinet I doubt they would allow it. (Probably, legal liability safety issues.)

Plain and simple the CT cabinet and the two 3" rigid riser mast conduits has to be bonded to the grounded conductor for electrical safety. At this point the only option I see is to install a bonding jumper from the CT cabinet to the main disconnect enclosure on their exteriors. I would have to set up an appointment with the POCO and have them remove their padlock to verify the area I drill the hole is clear of metering wires. Then drill the hole and bolt the lug to the cabinet. I will also be able to see if by chance the day of the shut down the POCO required the electrician to install a bonding jumper from the neutral block to CT cabinet. If by chance it was I won't need to install the bonding jumper from the CT cabinet to the main disconnect enclosure.
.

 

[Jamesco]

.

He basically has no more or less credibilit than someone like Mike Holt though. Yes he has knowledge and experience, and it on a CMP which maybe makes him have more credibility on discussions involving content that CMP is responsible for.

My post:

Just further validation for me after an AHJ electrical inspector told me I was wrong in my reading of 250.92 (B).

Paul Abernathy is one of the members of the CMP #5. Jmho, he is qualified to explain the meaning of 250.92 (A) and (B). I think he did a great job in his presentation on the subject matter.

Like I said in my post 'Just further validation for me' after an AHJ electrical inspector told me I was wrong in my reading of 250.92 (B).

I am still trying to figure out how to approach the electrical inspector and politely tell him he is wrong in his reading of 250.92(B).

The bigger problem is the electrical contractors/electricians that may be reading 250.92(B) the same way and the services they are installing are being inspected by the inspector.
Like the electrical contractor and his electricians that installed and wired my friend's new electrical service. Hey, it was inspected and passed by the electrical inspector, therefore it meets electrical safety code. (I am not implying it was the same electrical inspector)

 

[kwired]

Art 100


Point of attachment, connection, to the customer's service entrance conductors.


It's implied, premises wiring. Therein the customer's wiring.


Not in the metro or surrounding cities here. Power company owns the CTs, padlock, and meter. POCO is responsible for maintaining such. Customer owns and is responsible for maintaining everything else from the point of attachment.

When you get into rural areas of the State Utility Power Co ops rules can be and are different.

I should clarify what I said in an earlier post about bonding the neutral block in the CT cabinet to the enclosure. That could only be done with the permission of the POCO. To be honest because of the energized live parts inside the cabinet I doubt they would allow it. (Probably, legal liability safety issues.)

Plain and simple the CT cabinet and the two 3" rigid riser mast conduits has to be bonded to the grounded conductor for electrical safety. At this point the only option I see is to install a bonding jumper from the CT cabinet to the main disconnect enclosure on their exteriors. I would have to set up an appointment with the POCO and have them remove their padlock to verify the area I drill the hole is clear of metering wires. Then drill the hole and bolt the lug to the cabinet. I will also be able to see if by chance the day of the shut down the POCO required the electrician to install a bonding jumper from the neutral block to CT cabinet. If by chance it was I won't need to install the bonding jumper from the CT cabinet to the main disconnect enclosure.
.

Service point definition hasn't been in NEC for all that long, and a major reason for adding it was to create a transition point where utility installation/practices end and NEC begins to apply to the installation.

That said there still is no one defined point for every situation, two identical installs served by two different POCO's can have a different service point in each install.