Entergy Supply Side Disconnect - 480V Service

[nhee2]

I am looking at the requirements for a new overhead 480/277 service served by Entergy - their standards manual requires a non-fusible load break disconnect on the utility side of the meter and a service disconnect with OCPD on the load side.

Is the supply side disconnect governed by NEC? Since non-fused is generally 10 KAIC, not sure what products are available to serve this function. I assume the load side disconnect is the service disconnect is the location for the N-G bond. Is this configuration common for other utilities?

https://cdn.entergy-louisiana.com/userfiles/Global/Your_Business/installation_standards/2008/277_480VoltServiceOnPole.pdf?_ga=2.131257606.847502377.1599736583-1624814654.1599736583

 

[electrofelon]

I am looking at the requirements for a new overhead 480/277 service served by Entergy - their standards manual requires a non-fusible load break disconnect on the utility side of the meter and a service disconnect with OCPD on the load side.

Is the supply side disconnect governed by NEC? Since non-fused is generally 10 KAIC, not sure what products are available to serve this function. I assume the load side disconnect is the service disconnect is the location for the N-G bond. Is this configuration common for other utilities?

https://cdn.entergy-louisiana.com/userfiles/Global/Your_Business/installation_standards/2008/277_480VoltServiceOnPole.pdf?_ga=2.131257606.847502377.1599736583-1624814654.1599736583

That is a meter disconnect switch per 230.82(3) and is quite common for 480V self contained metering. Usually the 10K limitation is not an issue for overhead services, although it may be when the utility gives you bloated unrealistic numbers that are double what the actual fault current is. Often it helps greatly to request or get the actual transformer data and compute yourself.

All three pieces of equipment will be bonded to the grounded (neutral) conductor.

 

[tom baker]

We in here (Puget Sound Energy territory) have been required to have a disconnect ahead of the meter since 1982. It wasn't recognized by the NEC until about ten years ago. There is a picture Mikes code change book that I took of a 480V service with disconnect ahead of the meter, Our POCO puts a barrel lock in the disconnect as its theirs. But sometimes we used a fused disconnect, IE for a lift station.

 

[electrofelon]

We in here (Puget Sound Energy territory) have been required to have a disconnect ahead of the meter since 1982. It wasn't recognized by the NEC until about ten years ago. There is a picture Mikes code change book that I took of a 480V service with disconnect ahead of the meter, Our POCO puts a barrel lock in the disconnect as its theirs. But sometimes we used a fused disconnect, IE for a lift station.

Tom, that picture from my post is from a PSE service. They actually did not lock the NF disconnect (I assume that was an oversight) but it has been handy to have and I have used it several times because the service equipment is a MLO panelboard.

 

[nhee2]

That is a meter disconnect switch per 230.82(3) and is quite common for 480V self contained metering. Usually the 10K limitation is not an issue for overhead services, although it may be when the utility gives you bloated unrealistic numbers that are double what the actual fault current is. Often it helps greatly to request or get the actual transformer data and compute yourself.

All three pieces of equipment will be bonded to the grounded (neutral) conductor.

Thanks - I (obviously) did not open the Code book before posting my question - not sure that this configuration has come up for me before, but I see now that 230.82 would apply.

 

[nhee2]

We in here (Puget Sound Energy territory) have been required to have a disconnect ahead of the meter since 1982. It wasn't recognized by the NEC until about ten years ago. There is a picture Mikes code change book that I took of a 480V service with disconnect ahead of the meter, Our POCO puts a barrel lock in the disconnect as its theirs. But sometimes we used a fused disconnect, IE for a lift station.

thanks for the response

 

[tom baker]

Tom, that picture from my post is from a PSE service. They actually did not lock the NF disconnect (I assume that was an oversight) but it has been handy to have and I have used it several times because the service equipment is a MLO panelboard.

Yes same here, had two pump stations where large motor loads would run for a long time, overheated the meter socket terminals, real handy to have the disconnect ahead of the meter!

 

[tom baker]

Thanks - I (obviously) did not open the Code book before posting my question - not sure that this configuration has come up for me before, but I see now that 230.82 would apply.

Realize that the POCO have there own requirements, if they want the cash register painted purple you do that. The first time I did a 480 Service in 1982, we got a letter stating the sequence was switch fuse meter and I thought, well you never put a switch ahead of the meter, and I was wrong, and had to retrofit a swtich (non fused)