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View Full Version : What size breaker/wire did you use for your PM66?



Matt Allan
05-30-2005, 2:25 PM
Had a electrician come last week who was recommended to wire up my new shop as well as my new PM66 5hp. From the #s on the saw he said a 30amp breaker would do just fine. I found the manual so he could see it and he pointed out that the manual suggested a 40amp breaker and 10g wire. He said you can't do a 40amp breaker with 10g wire, has to be 8g and had no idea why the manual would have it as 10/40 instead of 8/40.

He thinks 10g 30amp will be fine, but figured I would ask what you guys did on yours before it is done. Should be calling me this week or next to setup a time to do all this.

Thanks
Matt

Jim DeLaney
05-30-2005, 2:29 PM
I have my 3 hp Shop Fox saw wired on a 30 amp breaker, using 10 gauge wire. Works just fine.

BTW, if you look at the power cord for you saw, you'll probably find it to be just 12 gauge. Most are.

Ken Garlock
05-30-2005, 2:54 PM
Hi Matt, how are things in "the rubber capital?"

A 3 hp motor running at 240v, under full load, will draw around 18 to 20 amps. A 5 hp will draw about 30 amps under full load. So take your choice, 30 amp breaker and 10 ga wire, or 40 amp breaker and 8 ga. wire. Don't need to worry about start up current as breakers are built to understand a large current surge for less than a second, that is enough to get your motor up and running.

BTW, I grew up in south Akron. It is a good place to be from. :o

jack duren
05-30-2005, 4:09 PM
Matt if hes a licensed electrician i think id just take his advise ;) .

i ran a 3hp unisaw on a 15 amp breaker/10 guage wire for a couple yrs and only had one trip and that was when a buddy from the cabinet shop thought he could push lumber through the saw like he did on the 5hp three phase at the cab shop....jack

Todd Burch
05-30-2005, 7:12 PM
I've been using a 30amp / 10gauge wire on my PM66 5HP since '97 with no issues.

Jim O'Dell
05-30-2005, 8:28 PM
Matt, for what it's worth, the GE load center box I looked at after work said motors 1 1/2 to 3 hp 30 amp curcuit. It didn't talk about wire size. Sounds like either way you go will be fine. I'm like Jack, though. Take the electrician's advise. If nothing else, you have a little headroom, and if you ever upgrade to a 5 hp..... Again, me with the "bigger is better" syndrome. It's a sickness I tell my wife, a sickness! ;-) Jim.

lou sansone
05-30-2005, 10:01 PM
I haven't looked at the code recently, but when I worked as an electrican 10 gauge romex was only rated for 30 amps as your electrician indicated.

lou

Greg Narozniak
05-31-2005, 12:18 PM
I've been using a 30amp / 10gauge wire on my PM66 5HP since '97 with no issues.

Ditto Except I have a Uni and only since 03 :)

Fred Ray
05-31-2005, 12:59 PM
Your electrician is dead right about #10 wire not being allowed on a 40 A breaker! I just checked the manual on-line and they are wrong!!!

To be sure you are right about what you do use:
1)Remove the motor cover on the left side of the saw and read the actual motor nameplate amps.
2) multiply that rating by 1.25
3) select a breaker rating equal to or higher than that number and select the wire according to the breaker rating.

for instance:
A motor nameplate of 24 amps X 1.25 = 30 Amps: therefore, a 30 amp breaker and # 10 wire works fine and meets all codes for a 230volt single phase motor rated at 24 amps or less.

A motor rating of 24.1 amps or higher will require you go to a 40 amp breaker and # 8 wire.

In some cases, when the length of the wiring is very long (say 200 feet or so), you would increase the wire size in order to reduce the voltage drop in the conductors. But NEVER use wire that is rated less than the breaker or fuse that protects it. That's what burns down houses and shops!

Sounds like you've got an electrician that knows what he's doing. I believe I'd keep him.;)

Tyler Howell
05-31-2005, 1:57 PM
I hard wired a 40 amp breaker and #8 wire. A 60 amp disconect at the saw.:cool: