Panelboard and Switchboard

[twinbeams]

How is one to determine the ampacity of a service? Is there a special marking on the power meter that denotes the ampage of the panel board or do you have to go solely by wire size, in accordance with table 310.15(B)(6)?

The panel I am in question about appears to be 100 amp service, with "boot-legged" in 200 amp panel board. From a glance from outside, the wires coming from the weatherhead that lead inside to the panel look to be more like #4 and they are definitely not 2/0. Does this mean the power company has to run in a 200 amp service, wires, meters etc.?

What I am looking at looks like a REAL good recipe for "fried wire". So can any of you shine a light on this for me? Thank you in advance for any help you can give me.

Ron

 

[bob]

Re: Panelboard and Switchboard

TB
The utility service size is not governed by the NEC. It will not match the ampacity of conductors in table 310.16. The utiltiy conductor is determined by their estimate of the peak load.
I would say that todays homes will have a 150 amp, or 200 amp service with some up to 400 amps. They may install #4 al triplex for a 100 amp or 1/0 triplex for 200 amp service. You need to determine the caculated load using the NEC as a
guide.

 

[russ]

Re: Panelboard and Switchboard

If there is a 200 amp main breaker, then the wire from the weather head to the meter and to the main should be 2/0 copper or larger.