Jointer tripping breaker

[Phil Maddox]

I', hoping this is a simple one, at least for you electrical heads out there. My BIL made an extension cord for my new-to-me 3hp,1 phase 12" jointer - plugged it in, something buzzed and nothing ran. For some unknown reason, I repeated this 2 more times. I then took apart the plug on the cord he made and he had the white and green wires reversed. I changed them, plugged it in and it started, ran for 2 seconds and shut down. Tried it on 2 other circuits, same result.

I'm hoping it is just the start or run capacitor. Any ideas?

Thanks

Phil

[Charles Lent]

A 3 hp motor is too large to run on a 20 amp 120 volt circuit. Are you connecting it to the correct power source? They are normally wired for and connected to 240 volt dedicated circuits. What is the motor set up to run on? Have you tried connecting it without using the extension cord? You will need to provide more details for us to help further.

Charley

[Phil Maddox]

Sorry - motor is 220v - wired into 220v circuit. I didn't know they made 3 hp motors for 120v.

[Don Jarvie]

Whats the amps on the motor at 220? If yor over 16 I'd put it on a 30 amp line (10g, 30amp breaker). You start up amps might be too much for the breaker to handle at the start. I run all my 3hp motors on 30 amps.

Instead of an extension cord swap put the line on the motor to 10g SWoJ cord or the rubber cord at HD or lowes with the approprate plug. I use a dryer plug. With the 30amp breaker and 10g line you should have no issues.

[Phil Maddox]

I should have posted more information - The cord is 10g, 600v 6 ft. long - plugged into and outlet 5 ft. from panel - 10g wire on this outlet also. I have 3 other 3 hp machines - Oneida SDG, RBI planer, and Unisaw - none trip the breaker ever. The DC draws a lot of current, I think = comparable to the jointer?

The real question is concerning the mis-wired extension cord - could htat have caused the start or run capacitor to die?

Thanks

[Joe Kaufman]

3 wire cord? White Black & Green?
Both 120V legs have contacts in the switch or starter?

Joe

[Don Jarvie]

The miswired cord would still let the motor run, but only at 1/2 power. You would get 110 instead of 220 and notice it when you try to plane something and it bogs down.

Do you have a starter on the machine? Make sure its wired correctly.

The true test is to run the line directly from the motor to the wall so the wall powers the motor. If it blows the breaker then its something with the motor, if not then it could be the starter or extension cord.

[Bruce Gray]

Just to ask the obvious ....the jointer does turn freely, does it not?

I would be inclined to remove the drive belt(s) from the motor. That will remove a lot of the intertia of that big knife head, and make starting easier. Sometimes, with a motor with no starting capacitor, I have found that giving the motor a quick spin by hand, then plugging it in, will cause it to start up.

I would not think that the mis-wiring would have damaged anything (If all was right to begin with). Normally, a locked rotor motor (ie from no start cap, bad centrifigal switch, etc) will "hum". You said that it "buzzed". It might be just semantics, but buzzing might mean arcing, and that would be a bad sign.

[Steve Meliza]

Your title says a breaker is tripping so I'm going to assume that is what keeps happening when it runs for 2 seconds then shuts down. Did this jointer run correctly for the previous owner when you went to go buy it or have you never seen it run before? Did you see any smoke or are there strange smells coming from the motor?

If it were me I'd take apart the motor far enough to see if anything looks fried. Then I'd take it to a motor repair shop for testing and repair if needed. Then I'd never let my BIL near electricity again.

[Phil Maddox]

This jointer was never run by the previous owner - still had(has) cosmoline all over it. I'm going to test the capacitor this weekend and might take it to a motor shop to have them go over it.

the BIL meant well. Nuff said.

Thanks