As Dean said, you need to furnish a lot more info. When you say that subs
you see are only 1 phase, you're correct, it's rare for a residential
service to have 3 phase. Are you looking to connect a machine that requires
3 phase or just not familiar with the terminology? You will need to know the
size of the existing service and some idea of what's attached to it
currently. You'll also need to provide details of what you're looking to
connect in the basement, to determine the feeder and panel size. BTW single
pole breakers do come in larger than 30 amp, however its usually more
practical to build the device to operate at 240 volt and keep the amperage
lower



wrote in message
oups.com...
Hello, I want to install new circuits in my basement and I want to do
it off of an electrical sub panel. The subs i see are only 1 phase.
How to I tap into the main box? Do i still use a double pole
breaker? Single pole breakers only go upto 30 amps. I want to run 4
separate circuits off the new box. Thanks.