Disconnect ahead of meter

C

curious101

Senior Member
Location
Atlanta, GA, USA
Hi,

Typical retail space project: electric service outdoors with multiple meters/disconnects for multiple retail spaces. Electric company requires the retail shop disconnects (not the service disconnects) to be installed before the meters. These disconnects would not have lock-outs and they would be fused. Is this NEC compliant? The inspector wants a letter from the engineer stating that this installation is acceptable.

Thank you!
 
qcroanoke

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
curious101 said:
Hi,

Typical retail space project: electric service outdoors with multiple meters/disconnects for multiple retail spaces. Electric company requires the retail shop disconnects (not the service disconnects) to be installed before the meters. These disconnects would not have lock-outs and they would be fused. Is this NEC compliant? The inspector wants a letter from the engineer stating that this installation is acceptable.

Thank you!
Click to expand...
So he wants your meter to have its own disconnect on the line side of the meter? Is this true of all the other meters?
 
C

curious101

Senior Member
Location
Atlanta, GA, USA
Dennis Alwon said:
Do you know why this would be done or required by power company.
Click to expand...
I don't know why. The designer who works on this job, asked me for advice. This job is in Summerville, SC. This is the quote from the email notification about this: "Berkeley Electric required the retail shop disconnects to be installed before the meters. The inspector is wanting a letter from the engineer stating that this installation is acceptable."
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Yes it is NEC compliant, see 230.82(3).

Note that the NEC does not care where meters are and doesn't require them to be present. I assume that we are calling the disconnects ahead of the meter 'not service disconnects' for some non-NEC reason, like a utility requirement to also have a service disconnect on the load side. The NEC would allow the disconnect ahead of the meter to be considered the service disconnect (if it met all applicable requirements) and would even allow bonding the meter enclosure to the grounded conductor if immediately on the load side. (See 250.142(B)exc 2). In these cases the NEC recognizes that sometimes utilities require things that call for the NEC being flexible.
 
C

curious101

Senior Member
Location
Atlanta, GA, USA
jaggedben said:
Yes it is NEC compliant, see 230.82(3).

Note that the NEC does not care where meters are and doesn't require them to be present. I assume that we are calling the disconnects ahead of the meter 'not service disconnects' for some non-NEC reason, like a utility requirement to also have a service disconnect on the load side. The NEC would allow the disconnect ahead of the meter to be considered the service disconnect (if it met all applicable requirements) and would even allow bonding the meter enclosure to the grounded conductor if immediately on the load side. (See 250.142(B)exc 2). In these cases the NEC recognizes that sometimes utilities require things that call for the NEC being flexible.
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The reason I called them "not service disconnect" is because there is an 800A service disconnect switch before the wireway which feeds (1) 400A, (2) 200A, (1) 100A meter/disconnects for the retail shops (see attached). The highlighted one is the service disconnect, but the whole discussion is about the retail shop disconnect switches which have red check mark on them. Those are not service disconnect switches, am I at mistake? I guess that's the question. Both 230.82(3) and 250.142(B)exc 2 talk about service disconnects. 1721228768006.png
 
qcroanoke

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
It looks to me like the meters are fed first then the disconnect is fed from the meter.
 
T

Tulsa Electrician

Senior Member
Location
Tulsa
Occupation
Electrician
Since there is a main those would be feeder taps. I could see where the disc ahead meter would be a good idea.

Would serve as protection for the meter enclosure and conductors as well as serve as cold sequence.
 
C

curious101

Senior Member
Location
Atlanta, GA, USA
I am the original poster.... Yes, the pdf shows current design, but the poco wants on the load side of the wire trough the disconnect switches to be ahead of the meters. I guess this is cold sequencing request, and we have to worry about current limiting fuses on the service disconnect switch? Otherwise the proposed design is NEC-compliant, correct? Thank you!
 
C

curious101

Senior Member
Location
Atlanta, GA, USA
curious101 said:
I am the original poster.... Yes, the pdf shows current design, but the poco wants on the load side of the wire trough the disconnect switches to be ahead of the meters. I guess this is cold sequencing request, and we have to worry about current limiting fuses on the service disconnect switch? Otherwise the proposed design is NEC-compliant, correct? Thank you!
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Or current limiting fuses in each individual disconnect? Whichever is NEC-compliant? Thank you!
 

Attachments

  • bus-ele-tech-lib-metering-equipment-protection.pdf
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qcroanoke

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Sorta retired........
curious101 said:
I am the original poster.... Yes, the pdf shows current design, but the poco wants on the load side of the wire trough the disconnect switches to be ahead of the meters. I guess this is cold sequencing request, and we have to worry about current limiting fuses on the service disconnect switch? Otherwise the proposed design is NEC-compliant, correct? Thank you!
Click to expand...
I agree with Jaggedben's
post # 9
 
J

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
curious101 said:
I am the original poster.... Yes, the pdf shows current design, but the poco wants on the load side of the wire trough the disconnect switches to be ahead of the meters. I guess this is cold sequencing request, and we have to worry about current limiting fuses on the service disconnect switch? Otherwise the proposed design is NEC-compliant, correct? Thank you!
Click to expand...
Ok, you have feeder taps, which arguably are required to land on disconnects before going to meters. So as far as I can tell the POCOs request only makes the installation more in line with NEC requirements, not less.

It's very unclear to me why in particular the inspector should have doubts about the compliance of the proposal.
 
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