That table only applies to dwelling services and their "main power feeder"
not to feeders in general




"Doug Miller" wrote in message
et...
In article , Bud--
wrote:
Doug Miller wrote:

For a 100A 240V feeder, you need three 4ga copper wires (type THHN or
equiv)
for the two hots and the neutral, and one 8ga copper wire, bare, for the
equipment ground. And that's going to mean a pretty substantial conduit.

Actually you need 3ga. 4ga is ok for a residential service. This is a
feeder.

Yes, I know it's a feeder -- I referred to it as a feeder. (see above)

Refer to NEC 2005 Table 310.15(B)(6) Conductor Types and Sizes for
120/240-volt, 3-Wire Single Phase Dwelling Services

****and Feeders****

Conductor Types RHH, RHW, RHW-2, THHN, THHW, THW, THW-2, THWN, THWN-2,
XHHW,
XHHW-2, SE, USE, USE-2.

AWG 4 copper is rated at 100 amps, AWG 3 at 110.

It's precisely *because* it's a feeder that 4ga is permitted -- if it were
a
branch circuit, it would need to be 3ga as you say.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.