400A meter can

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Hfalz1

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I am putting in a 400A single phase service. When i call the supply houses they tell me they have a 320A meter can. Can i use this can for a 400A service?
 
IF I remember correctly the rating is 320 continuous load and allows 400 amp non-continuous.
 
I'm not sure what's acceptable in other areas of the country but the last 400A service I did in my area required a CT cabinet. The POCO had me install an 1 1/4" gal conduit out of the CT cabinet into a 100A meter can and they took over from there, if my memory serves me correctly. They installed a special meter and ran x# of # 12's down into the CT cabinet.

Anyone else have a similar install or am I dreaming ? I'm going back about 12 years and it was an underground service.
 
320 dual lug meter bases have been around for many many years, They're very commonly used for two 200 amp panels. Especially in a house.

In commercial 400 amp services. I have seen engineers draw in a CT cabinet and a gutter to make it easier for future expansion. But they need to be sure they are going to expand. Other wise it's a waste.
 
Generally speaking, the 320/400a service uses a regular meter, the full 400a service requires the CT cabinet.
 
320 continuous is as large as they go for plug in style meters. There are bolt in style meters that have higher capacity ratings, but you don't see many of them around.

Bottom line most of the time is it is usually up to POCO what is acceptable.
 
LarryFine said:
Generally speaking, the 320/400a service uses a regular meter, the full 400a service requires the CT cabinet.
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Why would there be any difference between the two? Is the "full 400a service" considered to be 400 amp continuous? If so wouldn't that just be a 500 amp service?
 
infinity said:
Why would there be any difference between the two? Is the "full 400a service" considered to be 400 amp continuous? If so wouldn't that just be a 500 amp service?
Click to expand...


A meter rated continuous 400 amps is a bolt in style meter.

CT metering is generally involving a plug in meter, though at a lower current but proportional to the conductors that are intended to be measured.
 
kwired said:
A meter rated continuous 400 amps is a bolt in style meter.

CT metering is generally involving a plug in meter, though at a lower current but proportional to the conductors that are intended to be measured.
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So the only difference in Larry's post is the style of meter? A 320/400 is a plugin and a "full 400" is a bolt in?
 
infinity said:
So the only difference in Larry's post is the style of meter? A 320/400 is a plugin and a "full 400" is a bolt in?
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Larry only mentioned CT for full 400 A, but there is bolt in meters over 320, I have only seen maybe 4-6 in my lifetime, and don't know that those even exist anymore. Many POCO's just go with CT over 320.
 
infinity said:
Why would there be any difference between the two? Is the "full 400a service" considered to be 400 amp continuous? If so wouldn't that just be a 500 amp service?
Click to expand...
Yes, the "full" 400a means 400a continuous. Mathematically, what you say makes sense. I'm just relating how Dominion Energy does it.
 
I have always thought the class 320 nomenclature to be kinda annoying. First its a bit odd to have the continuous derating. Although some think it applies to everything, per NEC its just for conductors and OCPD's. I cant think of any other equipment that has the 80% derating, although sometimes you will see manufacturers instructions stating such. Second, if a class 320 socket isnt involved, we never qualify the service rating based on whether the loads are continuous or not. Also no one seems to take into acccount next size up rule. For some reason 320's get all this special treatment.
 
I'm just wondering if there is a reason for all of this confusion? If I install a 200 service in a house I don't call it a 160 amp continuous or a 160/200 amp service, it's just a 200 amp service.
 
Agreed. I also don't know why this one meter class is specified differently, but I do have a guess:

It may have something to do with the 320/400 meter base being most often used to supply two 200a breaker panels, rather than a single 400a panel.
 
LarryFine said:
Agreed. I also don't know why this one meter class is specified differently, but I do have a guess:

It may have something to do with the 320/400 meter base being most often used to supply two 200a breaker panels, rather than a single 400a panel.
Click to expand...

Would two panels vs. one panel really matter? I'm just trying to wrap my head around this 320/400 thing. :)
 
kwired said:
Larry only mentioned CT for full 400 A, but there is bolt in meters over 320, I have only seen maybe 4-6 in my lifetime, and don't know that those even exist anymore. Many POCO's just go with CT over 320.
Click to expand...
and if it is a 400 A service at a standard residential it may wind up with a 200 amp meter anyway (there are adapters for this).

A residence requiring 400 A for load (car charger? instant WH?) rather than breaker space may wind up on a demand rate.
 
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