I am about to start my wiring in my new workshop and was wondering what the
proper wire size is for the Unisaw and I also have a 230V Dust Collector.
Should I use 12/2, 10/2 or 8/2?
Also, anyone who has a unisaw 3HP, can you tell me what circuit size I will
It depends a little on how far you are from your load center (breaker
panel). I'm fortunate, as mine is right there in my shop, as is my
subpanel. If you have to go across half the house, go up a size
regardless (in other words, forget about the 12 gauge feeder)
The 12 gauge wire is sufficient for a 20A circuit; you'd need 10 gauge
A good argument can be made for running 10 gauge wire now while you
have the best access. That way, if you ever do get one of those 5 HP
machines, you'll have the capacity already in place. The difference in
price for a 20A duplex breaker vs a 30A duplex breaker is negligible.
The difference in wire costs will probably be on the order of 15 or
20%; insignificant compared to the cost/aggravation of wiring a new
30A circuit later.
Use the biggest boxes you can find for your receptacles because 10
gauge wire is a royal bitch to work with.
Also, although you mentioned two conductor wire, you may want to think
about 10/3 in order to have both a ground (required in any event) and
a neutral for future equipment that *might* require it.
Mine runs fine on a 20A circuit. Same with my 3 HP planer. See above
for NB regarding distance from panel.
Master Woodbutcher and seasoned termite
Shamelessly whoring my website since 1999
I believe you can go 100ft before having to worry about voltage drop, by
NEC. That's half way across a really big house.
It's a good argument to wire a bit over in anticipation of future needs.
Like LRod says - the difference in cost is really negligible.
Awe - 10ga is really not that bad. Big boxes are a good idea though. But
geeze - don't scare the poor guy into thinking he's dealing with entrance
cable. 10ga is a common find in house wiring and really is not that bad to
Off the top of my head, I can't think of anything a home shop is going to
use that would require 4 wire. But then again the reason my hair is so thin
is from saying "off the top of my head..."
Thanks for that correction Bob. I was not really sure, which is why I threw
in the universal disclaimer "I believe". I've heard a lot of
non-electricians make reference to this and even though I'd never read it in
the NEC I just assumed that I missed it. Admittedly, I've never taken the
NEC into the bathroom for really serious reading and read it cover to cover.
It has always struck me as wrong simply because even in a modest sized house
a branch circuit is very commonly a100 feet long. Hell - it does not take a
lot to run out 100 feet of wire. But, I've been proven wrong enough times
in my life to have learned to provide myself an out once in a while.
The voltage drop issue is probably one of the most compelling reason to run a
sub panel into your shop. Load diversity will tend to even out the load and the
feeder can handle the start up current over the long haul distances. You
machine drops stay short. Of course it also enhances expandibility and
flexibility in the shop when you have a panel there. Put a lock on it and you
have a way of securing the machines from curious kids.
What are the amp requirements for the saw and the DC? You can certainly run
one on a 20a circuit; the question is if you can run both. Probably, but
The second question is how far you are from the breaker box. If your load
is close to capacity and you are far away, you will have to step up in wire
The third question is whether you will ever want to run anything else on
this circuit; lights, air cleaner.
With that information, you can get an intelligent answer.
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