Perhaps I am in need of further explanation and education here. As a newby here, I have taken some time to read some posts and am familiar with the expertise of some of the senior members and moderators, and respect the opinions of them.
However, in the case of the 320/400 amp meter socket enclosures, I thought I had it understood, until this thread progressed.
According to 230.66, individual meter socket enclosures aren't considered service equipment, and aren't even required to be listed (nor are meters
).
I was under the impression that the smallest device determined service size. When a device is rated at 320 amps continious duty, where does the extra 25% come from? Isn't that like a 15 amp rated receptacle being able to legally carry 18.75 amps continiously?
I understand the 125% for continious loads for conductors, but there you calculate that a device requires "X" amount of current, then add 25%. That figure is it's continious rating, correct?
How can you take a device that has a 100%, or continious rating, and add another 25% to it?
I have seen the 320 amp meter socket enclosures supplying 2-150 amp panels, and some supplying 2-200 amp panels. I was under the impression that the AHJ was lax.
Could someone quote some code articles to set me straight?
It just seems odd to say a 320 amp continious rated device is rated for 400 amps continious duty is going the wrong way with the 125%. Why not just give the meter socket enclosure a 400 amp rating to start with? What about the 400 amp rated meter socket enclosures, are they to be, not derated, but rather increased 125% also?
