Powermatic Drum Sander Electrical Supply

[Dick Strauss]

It sounds like the OP got different info from PM that probably translates to 17A FLA/28A peak. If so, as Tom V said 30A circuit w/10g copper should be okay, right?

["Patrick G Rainsberger"]

"I called the Powermatic Tech. line and was told that it draws
28 amps at 230 and requires a 50 amp breaker. I called back to find out
if this was peak amps or continuous amps, and I got someone else, he told me it pulls 17 continuous amps and requires a 40 amp breaker."

Dick,

I don't know how to use all the tools for the Creek. Above is my quote on the original post.

The second tech told me that the first tech was wrong and wanted to know his name. Since then I've talked to an electrician and he told me I need a #10 wire and at least a 30 amp breaker. He said that the startup for a motor that size w/o a separate starter draws too much for a #12 wire.

Pat

[Rob Damon]

My take on it:

I have a:

-5 hp Dual-Drum sander (PM DDS225)
-5 hp 18" Delta RAS, 240V/1ph
-5 hp 20" planer (PM209), 240V/1ph
-5 hp 15" planer/molder (PM15), 240V/1ph
-5 hp 18" Bandsaw (PM1800), 240V/1ph
-5 hp Shaper (PM2700), 240V/1ph
-5 hp cyclone (Jet), 240V/1ph

They all start and run fine on #10, 30A/2P circuit breakers (L6-30R), because running load is roughly 17/18 amps for each.

Circuit breakers are designed to handle short time (first cycle(s) peak currents from motor starts. Some older breakers may have inrush problems, thus you can upsize the circuit breaker to accommodate inrush currents if you encounter niusance tripping (by code). Size the wire for 125% and use the next higher standard breaker size as a basis.

The wire doesn't care about a few cycles of inrush current, even at lock rotor, which is 6 times running current. (Which is why you size wires for fire pumps at 125%, but overcurrent protection at 6 times running current. You want the fire pump never to shut off once it starts. You want it to run until it destroy itself, unlike woodworking tools, where you want the overcurrent protection to trip before you have motor damage. The closer the Overcurrent is sized to the actual load, the better protection you have in place to protect the motor from damage.)
The #10 will only see the higher inrush for such a short time, so there won't be any heating issues, and it can handle 17amps all day long (continuous duty.)

Pm is probably recommending a 40amp, because it knows the starter overloads are going to trip to protect the motor and the higher breaker size will all but eliminate niusance tripping that has most likely occured in the past with past customers.

I have a new panel with new breakers 1-1/2 years old, so I haven't had any tripping issues.

Rob