I inspected a home that had three 200 amp service panels with a meter-base rating of CL 320, Which from what I can gather is a 400 amp service. Do you see any problem with this that I should let the client know?
Not with the meter…
So with the three 200 amp service panels, does this mean it’s a 600 amp service?
How are the three panels fed after the meter?
I’m not really sure. The meter box is flush with the exterior wall and these panels are on the other side of that wall.
Assuming these three panels are all connected to the load side of the meter the service size would be determined by the size of the service entrance conductors (SEC’s) feeding the meter. When there are multiple service disconnects those conductors are sized by a load calculation and are not required to be sized by multiplying the three panels by 200 amps each.
You would not need to have 600 amp SEC’s if the load calculation required for example only 400 amps.
NEC 230.90(A) exception #3
The rating of the SEC is allowed to exceed that of combined OCPD’s protecting it. Just like in a split-buss panel. You can have breakers (up to 6) that exceed the rating of the SEC feeding it. BTW, the 6-throw rule in the same enclosure is going away in NEC 2020 230.71(B) More rules, so little time! UGH!
So @rmeier2, since home inspectors don’t always have access to see the entire SEC (especially when underground), what are the options other than listing the service rating as “unknown”.
IMO you follow the SOP for determining the service size. If you still cannot determine what it is then list it as you’ve suggested as unknown. One thing I wouldn’t do is use the nameplate on the meter.