Service Size Determinant for Meter Collars

B

BarklieEstes

Member
Location
Richmond, VA
Occupation
Master Electrician
Greetings,

I frequently encounter services that consists of (2) 200a indoor load center fed from a CL 200 utility meter. Assuming the utility approves a design for a meter collar interconnection, is it code compliant to install a Tesla Backup Switch in these instances? The Installation Manual says nothing about amperage requirements. The Specification Sheet only says that the rating is 200a continuous.

I gather that the utility is allowed to feed 400a worth of equipment from a 200a meter because they're the utility and they do what they want. I'm wondering if that logic extends, at least partially, to meter collars, and if not what the Code violation would be. It seems like it would be a reach to call out a 110.3(B) violation since the listing instructions don't include any requirements regarding OCPD.

Regards,
Barklie Estes
 
BarklieEstes said:
Greetings,

I frequently encounter services that consists of (2) 200a indoor load center fed from a CL 200 utility meter. Assuming the utility approves a design for a meter collar interconnection, is it code compliant to install a Tesla Backup Switch in these instances? The Installation Manual says nothing about amperage requirements. The Specification Sheet only says that the rating is 200a continuous.

I gather that the utility is allowed to feed 400a worth of equipment from a 200a meter because they're the utility and they do what they want. I'm wondering if that logic extends, at least partially, to meter collars, and if not what the Code violation would be. It seems like it would be a reach to call out a 110.3(B) violation since the listing instructions don't include any requirements regarding OCPD.

Regards,
Barklie Estes
Click to expand...
Normally it is a 320 amp meter base, and is a bolt in meter, not a standard plug in meter. If it is a bolt in meter, the Tesla collar will not physically work. Someone may have used a 200 amp service to feed two 200 amp panels. Does the meter base look unusually large for the meter? Then it’s probably a 320 amp meter.
 
I would say that pedestal is only rated for 200 amps, don’t have much for electrical inspections there? If they passed that, you are not going to have any problems with the Tesla collar! LOL!
 
You should check with the utility. They could have used a CL200 meter in a 320 cabinet. It is the same socket.

To ultimately answer your question though, the utility will decide on if you can use that tesla back up switch. If it is rated 200A then you have limited the service to 200A and will need to to verify that with load calcs.

Given the utility put in a CL200 meter, you are more than likely okay. They would have noticed the customer hitting the max demand amount (if they meter demand). You can also ask them for the billing / month reads for sizing purposes to answer that question.
 
Thanks. The NM application already solicits the method of interconnection and makes us select the make/model of the meter collar being used. The utility already approved all that. My fear is that I install it and the electrical inspector fails it. I know that the NEC does have a few things to say about meter collars but unclear as to whether those things only apply when installing in a private meter base. It sounds like that's the case.
 
BarklieEstes said:
Thanks. The NM application already solicits the method of interconnection and makes us select the make/model of the meter collar being used. The utility already approved all that. My fear is that I install it and the electrical inspector fails it. I know that the NEC does have a few things to say about meter collars but unclear as to whether those things only apply when installing in a private meter base. It sounds like that's the case.
Click to expand...

This has been my little issue with meter collar interconnections. The install instructions vs utility vs NEC. It is hard to tell if you need to install a 200A main on the service. Maybe their install instructions are more clear as to the requirements on OCPD. I was looking at one the other day that required 200A OCPD. I don't think you are meeting something like that.
 
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