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GE 1 1/8 motor hums, pops fuse.

Posted: Tue Feb 09, 2016 10:05 pm
by kurtzz3
Again, this is with a GE 1 1/8 motor in a Mark V made in July, 1981.

This happened right in the middle of a project. Without making any adjustments, I went to turn on the switch. The motor hummed for about 1 to 2 seconds when turned on then the fuse on power strip pops. The shaft never turns on its own.

I disassembled the head stock and removed the motor completely.

Since new capacitors are only about $7, I went ahead and replaced it. Still no go.

The motor turns by hand freely, with no binding or scraping sounds. The bearings feel fine and the pulley shivs do not contact the motor housing. I can hear the motor TRY and turn, but nothing.

I don't see any external relays and such. Are they internal to the motor?

What should be my next course of action. Thanks, all!

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Tue Feb 09, 2016 10:43 pm
by billmayo
I have had to replace the motor (internal & external) wiring on every GE 1 1/8 HP motor (dozens) that I disassemblied. The insulation breaks down and can short internally. Yes there are start winding points that you can clean while you have the motor disassembled. You should replace the bearings at this time too. I recommend sealed bearings for these motors.

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Tue Feb 09, 2016 11:00 pm
by kurtzz3
Are the problems you've encountered something easily repaired by an owner (I am reasonably mechanically inclined)? and the parts easily obtained?

I see a service on Ebay that will rebuild a motor for about $70 not including shipping both ways. I'm more concerned with the time that will take. I'd like to get up and running again as soon as possible, which is why I'd rather do it myself.

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Wed Feb 10, 2016 1:17 am
by JPG
Problem cause : "power strip".

Problem detail : The power strip introduces considerable additional resistance to the power source. The motor draws an exceptionally large current when starting. The power strip and it's power cord are not capable of allowing startup current to reach the motor and it becomes slow to start. The circuit breaker on the power strip is grossly under sized to pass the startup current.

Problem made worse : The motor becomes starved for voltage and the startup surge time is greatly extended. This creates heat in the windings and the insulation may break down.

If all this happened you have a counter weight(aka boat anchor).

If the insulation has not broken down, it may still work if given adequate power supply as it attempts to start. No added power strip or extension cords. Minimum of #14 power cord of no more than a few feet long.

A second likely cause : The internal start switch is not closing when stopped. That prevents the start winding from becoming energized.

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Wed Feb 10, 2016 8:02 am
by dusty
kurtzz3 wrote:Again, this is with a GE 1 1/8 motor in a Mark V made in July, 1981.

This happened right in the middle of a project. Without making any adjustments, I went to turn on the switch. The motor hummed for about 1 to 2 seconds when turned on then the fuse on power strip pops. The shaft never turns on its own.

I disassembled the head stock and removed the motor completely.

Since new capacitors are only about $7, I went ahead and replaced it. Still no go.

The motor turns by hand freely, with no binding or scraping sounds. The bearings feel fine and the pulley shivs do not contact the motor housing. I can hear the motor TRY and turn, but nothing.

I don't see any external relays and such. Are they internal to the motor?

What should be my next course of action. Thanks, all!
Open the motor for a thorough visual inspection.

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Wed Feb 10, 2016 10:38 am
by kurtzz3
The power strip is not one of those little plastic household variety. This is a large capacity power strip designed for use around large power tools.

Are there any things to be aware of when removing the end plates for this motor? Springs that will shoot off into space, etc?

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Wed Feb 10, 2016 11:12 am
by JPG
Ok so it is 'beefy'! If it has 'worked' in the past, go back to it after getting this running.

No there are no booby traps inside, but care needs to be taken so as to not add new damage. Before taking it apart, score the end cap and outer shell so it can be reassembled the same as before.(makes getting the tie screws back in easier).

Now once inside, check the switch contacts. Most likely they are failing to 'make'.

Give it the 'smell' test to detect possible burned windings.


I be curious what the beefy strip has for a power cord.

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Wed Feb 10, 2016 12:13 pm
by dusty
JPG wrote:Ok so it is 'beefy'! If it has 'worked' in the past, go back to it after getting this running.

No there are no booby traps inside, but care needs to be taken so as to not add new damage. Before taking it apart, score the end cap and outer shell so it can be reassembled the same as before.(makes getting the tie screws back in easier).

Now once inside, check the switch contacts. Most likely they are failing to 'make'.

Give it the 'smell' test to detect possible burned windings.


I be curious what the beefy strip has for a power cord.
Most probably a beefy cord and plug.

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Wed Feb 10, 2016 12:37 pm
by kurtzz3
I'm having a difficult time uploading a photo, so I'll add a link to the Home Depot equivalent.

http://www.homedepot.com/p/Belkin-10-Ou ... /100663223

Re: GE 1 1/8 motor hums, pops fuse.

Posted: Wed Feb 10, 2016 8:01 pm
by JPG
A 15 foot power cord that is likely #14 or #16.

I would not use it for the SS.

Time to look at the start switch.