600a ring-type meter socket with bypass?

[Tyler55]

Hello everyone,
Thank you for having me here. I'm having a power upgrade done on my shop and I have been tasked with finding the meter panel. The POCo has given me their requirements as being a ring-type panel with bypass. It is single phase 600 amp. I cannot find a panel that is 600 amp with ring and bypass. We were originally going to install a "dual 400" but after months of communication with the engineer at the POCo, he emails me to inform that "after speaking with the meter shop, and researching NEC" we cannot install two panels on the building and I cannot have 800 amp without going to 3-phase, which is two miles away.
Does this all sound correct?
I'm having a hard time taking his word, and my electrician is not available at the moment.
Does anyone know of a manufacturer of a 600 amp ring-type panel with bypass?
Is it possible to have one custom made by Eaton or Milbank?
Any suggestions would be appreciated.
Thanks.

 

[ActionDave]

This question can be answered as it is only a request for information and not "how to".

 

[tom baker]

What the POCO is telling does not seem right. Can you get a copy of their customer handbook?
My POCO would require a CT service.

 

[Tyler55]

What the POCO is telling does not seem right. Can you get a copy of their customer handbook?
My POCO would require a CT service.

Thanks Tom,
I found the Service Entrance construction section of the handbook. I believe you are correct that they would require a CT Meter. I'm convinced that my contact at the POCO is new at this, as he has not mentioned " CT Meter".
According to the requirements, a maximum of 600a in single phase is allowed unless an exception is granted by engineering department.
Do you have any ideas on how I might get them to make an exception and approve a 800a single phase service?
Link for the service entrance manual below.
https://navopache.org/https-navopac...-entrance-requirement-manual_rev1_231002-pdf/

 

[tom baker]

On exception, no.
But an 800 A single phase service would be unusual. But would 3 phase 120/208 would be more cost effective, even with the cost to extend 3 phase?

 

[Tyler55]

On exception, no.
But an 800 A single phase service would be unusual. But would 3 phase 120/208 would be more cost effective, even with the cost to extend 3 phase?

Possibly, I think they said $9500 per mile. Without the phase upgrade I think 600a will be the max. Thanks for pointing out the C.T panel and the customer handbook. Hopefully I'll hear back from the POCO soon on the C.T panel.
Cheers,

 

[jaggedben]

I could be wrong but I'm pretty sure that the Form 2S meter standard does not go above 400A (320A continuous). At 400A you start to see bolt-on and CT type meters. These meters don't use rings, as far as I've ever seen. (Or if it's a CT meter, the socket would not need to be rated 600A.) So you would not see a 600A rated ring type socket, single phase. I don't believe it's a thing.

But that said, the utility should know this and not be asking for it. Someone is confused.

Also there is no NEC prohibition on having two 400A service entrances on a single service. But I would guess their policy on going to 3-phase applies to such a service anyway.

 

[Tyler55]

I could be wrong but I'm pretty sure that the Form 2S meter standard does not go above 400A (320A continuous). At 400A you start to see bolt-on and CT type meters. These meters don't use rings, as far as I've ever seen. (Or if it's a CT meter, the socket would not need to be rated 600A.) So you would not see a 600A rated ring type socket, single phase. I don't believe it's a thing.

But that said, the utility should know this and not be asking for it. Someone is confused.

Also there is no NEC prohibition on having two 400A service entrances on a single service. But I would guess their policy on going to 3-phase applies to such a service anyway.

Thanks for your reply. I did find a metered ring-type transformer cabinet from Milbank. My question to the POCO is at the bottom. Any help figuring out a panel or CT cabinet combo would be super helpful.
They have gone back and forth three times and I have already put down a deposit after they said it was possible the first time.
"After talking to the meter shop and studying the National Electric Safety Code I was made aware that if it is physically possible to get a single meter panel that matches your load calculations we cannot have 2 panels to equal your loads calculations. (If a large commercial building needing let’s say 5000 amps that’s when it would pass the electric code to have two 2500 amp panels because there physically is not a 5000amp panel)"..."As far as the possibilities of an 800amp we cannot feed an 800amp panel with only single phase so that can’t be a scenario. My apologies I let this get this far with the two 400a panels idea. Do a little bit of looking around for a 600amp panel."
From POCO service entrance pamphlet:
Section 602.01 states that all socket enclosure shall be the ring-type.
Section 602.18 states that service exceeding 200a is required to have C.T Metering.
Section 602.17 states that safety test blocks are required as well as manual bypass type blocks.
Section 602.19 states that the co-op will furnish B) Current Transformers(metering). D) Test switches.
If the above is correct, then my understanding is that to furnish a C.T Cabinet for 600 amp single phase service, the C.T cabinet must contain a ring-type meter socket, Manual bypass, and test block.
Would ring-type metered transformer cabinet U3565-O from Milbank with CT cabinet mounting rack K4795 also Milbank work? Am I totally lost or on the right track?

https://www.milbankworks.com/getmedia/7feb57a9-d88c-4fdf-8386-6a117f53534a/instrument-rated.pdf

 

[jaggedben]

Sorry, CT metering details are really outside my expertise. But what I can say is this:

The utility pamphlet you quoted says you need CT metering over 200A. And it appears you are expected to provide the CT cabinet and it must have certain features. The bussing in the CT cabinet (see examples on pg 22 among others in the PDF you linked to) must be rated minimum 600A for a 600A service. The meter socket for a CT meter does *not* need to be 600A rated. Note the example you asked about is 20A: this is fine.

This is all separate from the service equipment, informally known as a service 'panel'. When the utility guy telling you to find a '600A panel' he is talking about the service equipment, not the metering.

So, two different tasks:
1) Find an appropriate CT cabinet with 600A *bussing* and appropriate transformer (CT) rated meter socket, ring type.
2) Find a 600A rated service panel. (Which the poco should be less picky about.)

You should really have your electrician help you with this and probably wait until he is available before submitting any proposed equipment to the utility.

 

[Elect117]

Possibly, I think they said $9500 per mile. Without the phase upgrade I think 600a will be the max. Thanks for pointing out the C.T panel and the customer handbook. Hopefully I'll hear back from the POCO soon on the C.T panel.
Cheers,

That is a pretty good price. You will save long term with the 3ph system over the single phase. You can reduce your panel size and balance your 2 pole and single phase loads.

What is the cost difference between the larger wire needed on the 1ph 800A and the related switchgear vs a 400A 3ph board and related wiring?

I think it will end up being a better choice. You might want to also ask what the cost would be to increase your single phase load. They might end up charging you quite a bit anyway to do the upgrade.

 

[Tyler55]

Sorry, CT metering details are really outside my expertise. But what I can say is this:

The utility pamphlet you quoted says you need CT metering over 200A. And it appears you are expected to provide the CT cabinet and it must have certain features. The bussing in the CT cabinet (see examples on pg 22 among others in the PDF you linked to) must be rated minimum 600A for a 600A service. The meter socket for a CT meter does *not* need to be 600A rated. Note the example you asked about is 20A: this is fine.

This is all separate from the service equipment, informally known as a service 'panel'. When the utility guy telling you to find a '600A panel' he is talking about the service equipment, not the metering.

So, two different tasks:
1) Find an appropriate CT cabinet with 600A *bussing* and appropriate transformer (CT) rated meter socket, ring type.
2) Find a 600A rated service panel. (Which the poco should be less picky about.)

You should really have your electrician help you with this and probably wait until he is available before submitting any proposed equipment to the utility.

I agree with involving the electrician, however I am in a rural area and only have the one available who is super busy and hard to bounce ideas off. I really need to have this narrowed down first. The POCO has to approve the meter panel, he didn't mention anything about service panel requirements.
My original thought was to have the meter feed four 200a main breakers which would feed four 200amp service panels inside the building for a total of 800a.
Can I do the same thing only with three 200a (600a total) main breakers or do I first need to feed a 600a service panel before any 200a panels? I read in the NEC2020 that up to six service disconnects are allowed as long as they are grouped and each in their own panel.
Idea map: Transformer to 600a bussed CT Cabinet/ Meter socket via underground, CT cabinet to three 200a main breakers, 200a main to service panel. Is this feasible?

 

[tom baker]

That is a pretty good price. You will save long term with the 3ph system over the single phase. You can reduce your panel size and balance your 2 pole and single phase loads.

The three phase panel will give you 1/3 more single phase circuits in about the same space
But….how many loads require 240 volts and will those work at 208 volts?
If they are motor loads, can the motors be charged to 208 3 phase? Motors are smaller and start easier.

 

[Tyler55]

That is a pretty good price. You will save long term with the 3ph system over the single phase. You can reduce your panel size and balance your 2 pole and single phase loads.

What is the cost difference between the larger wire needed on the 1ph 800A and the related switchgear vs a 400A 3ph board and related wiring?

I think it will end up being a better choice. You might want to also ask what the cost would be to increase your single phase load. They might end up charging you quite a bit anyway to do the upgrade.

"You can reduce your panel size and balance your 2 pole and single phase loads."(Elect117). This is a little over my head, I'm not an electrician. I'm guessing it is similar to going from 120 to 240 where I can cut the amps in half. The power upgrade from 200a to 600a is only around 5500 plus conduit gravel etc. To bring in three phase would add about 20K and I still have to do the underground feed. I think I'm going to try and make the 600a service work.
Thanks

 

[Tyler55]

The three phase panel will give you 1/3 more single phase circuits in about the same space
But….how many loads require 240 volts and will those work at 208 volts?
If they are motor loads, can the motors be charged to 208 3 phase? Motors are smaller and start easier.

I don't have any three phase equipment as its never been available. Most of everything is 220-240 rated. Some things will run on 208 like the compressor but it would be de-rated by 75%. I'm not running any big motors other than the ventilation and air comp.

 

[Tyler55]

I should add that an electrical engineer and architect will be drawing plans for the permitting process and that I am not DIY. The problem that I run into is the first thing they need to know is how much power is available in the building. With the need for the upgrade I am attempting to future-proof as much as possible. Once the POCO has approved a panel, I can have an engineered drawing made for everything beyond the meter. I think the POCO only is only concerned with everything up to the main service disconnects.
Thanks for everyone's input.

Can I use three 200a main breakers as service disconnect? Grouped together each in individual panels?
Everything over 200a is pretty expensive.

 

[jaggedben]

You can use three 200A breakers as service disconnects for a 600A service. In fact, you can use four, as long as the calculated load is still 600A. In my opinion that part of things should be none of the POCOs business and can be figured out by your engineer and electrician once you settle on what the POCO is providing at the CT cabinet. But your mileage may vary.