Installing HSB generator to combo meter pan

[patricknola]

Good morning, I've got a customer who bought a hsb generac generator and would like it installed(i'm a LA state licensed electrician and generac authorized). When I go by to give the quote, the customer has a 200 amp milbank combo meter pan, underground, with 12 spaces. Normally I run conductors from the load side of the meter to the line side of the transfer switch. On this combo meter pan there are bars running from the load side lugs to the bus bars where the breakers are installed, making it impossible to re route power from meter to transfer switch and back to breaker portion of combo meter pan. I was going to install a 200 amp 12 space underground with a main breaker but I cannot find one that has dimensions that will accomadate the conduit entering and exiting the bottom and back of the enclosure, the amount of wire available from POCO and also have 12 spaces with a main breaker I can connect a transfer switch to. Any idea's?

 

[Little Bill]

If the 12 circuits in the meter/main are to be backed up by the generator, then you're stuck with moving them to another panel as you can't modify the meter/main to intercept the load side of the meter.

 

[patricknola]

If the 12 circuits in the meter/main are to be backed up by the generator, then you're stuck with moving them to another panel as you can't modify the meter/main to intercept the load side of the meter.

If the 12 circuits in the meter/main are to be backed up by the generator, then you're stuck with moving them to another panel as you can't modify the meter/main to intercept the load side of the meter.

Do I have to derate conductors when i splice and is there a particular art in the nec that covers derating conductors due to splicing ?

 

[Little Bill]

There is a rule for splicing in a panel which says not to. But many stop reading there. It goes on to say UNLESS you use up a certain amount of space in the cross section area, you can splice. It would take a huge amount of splicing to go over that limit, so splicing can be done. As far as derating, if the raceway you are using to move the circuits isn't over 24", then you won't have to derate unless you go over the fill percentage of the "nipple". Given the small amount of circuits involved, I doubt you would go over the fill percentage if the correct size raceway is chosen.