"Toller" wrote in message
...
I have put off installing a transfer switch because the cable will need to
be run the length of the house (all those joists to drill through) and the
expense.
Well, I found a half price 5000w switch at HD and a half price right angle
drill at Ebay, so I am going to do it; but what cable size.

I have a 13a genny that satisfies all my needs. It would only require
14/2.
But as long as I am doing it, I might as well install a 12/3, as the next
owner might be more demanding. The cable won't be that much more, or be
that much harder to use. However, the 12/3 is only good to 4800w, and the
switch is 5000w. Would those lousy 200w make any real difference?
Obviously they would need a 5000w genny, and even then it would only be
above 4800w for very short and rare instances.
I really don't want to use 10/3. It is expensive and hard to work with,
and
will require a significantly larger hole in the joists. Does code get
involved here? Can I simply say that it is only for use with 4000w and
smaller generators? I have no intention of ever going above 1600w, and
expect to live here for the next 10 years at least.
Thanks.

As long as the cable is protected by an overcurrent device, say fuses or a
circuit breaker you could use a 5000 AMP transfer switch. As long as you do
not exceed the rating there is nothing that says you can not be under it.
Check your voltage drops to the end recpts to make sure the 12-3 is big
enough.

Did you provide for the derating of the 12-3. Your only allowed 80% draw on
a 20 amp circuit.