277/480 meter base

WCEI

WCEI

Senior Member
Location
Central Virginia
Occupation
President/Owner, Wayne Cook Electric, Inc.
I was having a conversation with a utility power company supervisor that is a good friend, and he asked a question that I’m just not sure of.
Let me qualify the situation here in Virginia. The service drop or laterals, up to, and including the meter base are the exclusive property of the power utility company. Up to a few years ago, the power company provided a meter base for a 277/480 volt service up to 200 amps. (Now, all services in this voltage class use CT cabinets).

He had some conflicting information provided to him that stated that 277/480 v services were required to have a disconnect ahead of the meter base. Supposedly this was an NEC requirement. He also had conflicting information from other sources that stated a disconnect was prohibited ahead of the meter base. And one more aspect to this question. His company guidebook says no disconnect unless required by the local jurisdiction. (Just FYI, in Virginia, a locality cannot add to or take away from the State Code, which of course is the NEC.)

So, what do we know about disconnect requirements or prohibitions ahead of a 277/480 volt meter base?
 
Where's the service point? The NEC has nothing to say about what happens on the utility side of the service point.

Cheers, Wayne
 
wwhitney said:
Where's the service point? The NEC has nothing to say about what happens on the utility side of the service point.

Cheers, Wayne
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I wonder where the service point starts? Is it universally accepted to be somewhere? The weather head? The meter base?
 
WCEI said:
I wonder where the service point starts? Is it universally accepted to be somewhere? The weather head? The meter base?
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Only your utility can tell you that...the service point is where ever the utility says it is and it is not universal.
In my area for an overhead service it is at the utility pole for commercial buildings and at the weatherhead for dwellings.
 
don_resqcapt19 said:
Only your utility can tell you that...the service point is where ever the utility says it is and it is not universal.
In my area for an overhead service it is at the utility pole for commercial buildings and at the weatherhead for dwellings.
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for commercial overhead, do you supply and/or install the overhead wire if it is on your side of the service point?
 
My POCO has required a disconnect ahead of the meter for 277/480 since 1980. It’s typically an unfused disconnect, with poco lock.
 
In my part of Virginia, the utility company is Appalachian Power. (I'm guessing it's Dominion for the OP.)
All the 480V services I've done have been with a CT cabinet, so I can't speak directly to the question but will note for us: The utility will provide a meter base, but once installed, it is the property of the customer. The customer is also responsible for the service riser if overhead. For underground, we usually supply a piece of pipe, 90° elbow, and TA to come up to the meter, and the utility installs that with their conductors.
 
Electromatic said:
In my part of Virginia, the utility company is Appalachian Power. (I'm guessing it's Dominion for the OP.)
All the 480V services I've done have been with a CT cabinet, so I can't speak directly to the question but will note for us: The utility will provide a meter base, but once installed, it is the property of the customer. The customer is also responsible for the service riser if overhead. For underground, we usually supply a piece of pipe, 90° elbow, and TA to come up to the meter, and the utility installs that with their conductors.
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It’s Dominion Energy here. They provide a CT cabinet set up now, but used to provide a meter base for up to 200 amp services until some time in the recent past. I only put a very few up in my career that got a meter base, and it never came up from DE or the inspector that a disconnect on the line side was even an option.

DE, and for most of the Coops, supply all meter bases. DE are always free, but the Coops charge for theirs. The property owner, (the electrical contractor), is responsible for installing the meter base and the service up to the attachment point, except DE installs the service to 200 amp,
1 phase, overhead services. Underground services occasionally require the electrician to stub down, but not often.

But, the service from the attachment point, to and including, the meter base is under the exclusive control of to power company. Dominion Energy will furnish replacement meter bases at no cost for any legitimate reason. The coops typically charge for their meter bases unless it is some type of extraordinary circumstance. But, installation and repairs are on the electrician.

I’ll look through DE’s “Blue Book” tomorrow and see how it words the installation requirements for these higher voltage services. Truthfully, I honestly think that over the years it was installed with or without a disconnect on the line side, based on what the installing electrician thought was right.
 
It’s called “cold sequence metering” very common on 277/480 metering 200 amps and less. Anything over 200 amps here requires a ct cabinet. Since the meter is plug in, it’s probably for the safety of the meter installer due to higher available current.
 
hillbilly1 said:
It’s called “cold sequence metering” very common on 277/480 metering 200 amps and less. Anything over 200 amps here requires a ct cabinet. Since the meter is plug in, it’s probably for the safety of the meter installer due to higher available current.
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I finally had a minute to look through the NEC (2020), to see if I see anything that might apply. 230.82 was the only thing that I could find.
.(2) allows meters ahead of the service disconnect and .(3) allows a “meter disconnect switch.”

I could not find anything in the code that singles out 277/480 volt services for requiring a disconnect ahead of the meter base. Nor did I expect to because in virtually all cases this is the domain of the power company.

Dominion Energy installations are guided by their “BLUE BOOK.” I looked through this book pretty thoroughly and the only thing I found was a diagram under the section for “seven or more meters on one service” that shows a disconnect ahead of meter gangs. I found no reference to specific requirements for a 277/480 volt services. Probably because ALL 277/480 volt service are now CT services so they have no need to address merit base services of this type.

The bottom line is that I only brought this topic up because a power company rep was asking me was a disc required ahead of the meter base by the NEC, or was it even permitted.

Unless someone tells me otherwise, I would say that nothing in the NEC requires it or prohibits it, and his Blue Book does not prohibit it but allows it because the NEC allows it. Your thoughts?

Thank you Hillbilly 1. Is that term, cold sequence metering, a local term or a trade term that I’ve just never heard before?
 
WCEI said:
.

The bottom line is that I only brought this topic up because a power company rep was asking me was a disc required ahead of the meter base by the NEC, or was it even permitted.

Unless someone tells me otherwise, I would say that nothing in the NEC requires it or prohibits it, and his Blue Book does not prohibit it but allows it because the NEC allows it. Your thoughts?
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My thoughts have not changed since Post number four 😉
 
WCEI said:
I could not find anything in the code that singles out 277/480 volt services for requiring a disconnect ahead of the meter base. Nor did I expect to because in virtually all cases this is the domain of the power company.
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As mentioned, the only thing in the code touching on this is 230.82, which makes no mention of voltage, CT vs self contained, or anything else.

Addressing the part in red, this is one of those regional or POCO to POCO things., and that statement is extremely foreign to me. I dont think I have ever worked on a job where the service point was after the meter. Where I have worked, the meter socket is provided owned and maintained by the customer. The service point is before the meter.
 
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