On May 16, 1:28 pm, "RBM" rbm2(remove wrote:
As the others have indicated, you need to rethink this. 125 amp sub panel in
the same building as the main panel doesn't require a disconnect in it or at
it. If you need a 125 amp feeder, I believe it's 1/0 copper, which you can't
pull three plus ground through a 1 inch conduit

"tr" wrote in message

oups.com...

I am adding a 125 amp subpanel to the far side of my house. I need to
add a disconnect breaker near the new subpanel...but...I can not find
anything rated at 125 amps at either Home Deport or Lowes. The
largest they have for disconnect is 70 amps for a spa setup.?

Do I need to find a electrical supply house for this...or is there
something I am missing at Home Depot ?

Also...I am running a feeder line from the main panel to this
subpanel...the run is about 100 ft...can someone tell me what the code
is regarding the size of wire needed for this run. The retired
electrician at Home Depot says a 4awg three connector cable will be
fine...it is being run through 1" EMT across a flat roof with rain
tight compression connectors ?

Thanks, Tim

Tim-

4 Gage is fine IF you're running in air.........

in conduit you need to bump up to at least 2 gage

& you're allowed three of them in a 1" conduit but you need a ground
as well.....you "might" be able to sneak a smaller ground conductor in
there (if allowable) but you'll have to do the fill calc

Double check your ampacity (in a conduit) & make sure you spec the
correct wire .......to get the highest ampacity you'll need THHN rated
conductor

do you really need 125 amps? 95 amps could be done with 4 gage THHN
in a 1" conduit but than would be a tough pull.

if the 1" conduit is already in, sounds like you're going to be
conduit limited on your ampacity


For a sub panel like you're talking about......I'd use 1.25 or 1.5"
conduit to make my life easier

double check my info before cutting any cable

cheers
Bob