7" Milwaukee Grinder Won't run?

[jbaccell]

Good Afternoon,

I have an old 7" Milwaukee bench grinder that has given me many years of service. When I flip the switch, it just hums but if I spin thew wheels she fires up. First thing that came to mind is the start capacitor is bad and after testing capacitance with my meter, it seemed I was correct as the capacitor was bad. I bought a new capacitor and after installing it, the same problem still exists. I believe the culprit is in the attached photo. I am not sure what it does or what it's called but it is wired in with the switch and capacitor. Any insight and/or advice would be appreciated.

Thank you,

Joe

 

[T Bredehoft]

googling the number illustrated above produces:

3CR SERIES| MOTOR STARTING RELAYS - Sensata​

Sensata 3CR Series Motor Starting Relays Datasheet Author: Sensata Technologies Subject: Klixon® 3CR series current type motor starting relay designed for single-phase AC applications. Motor start winding currents to 15 Amps. Eliminates space consuming centrifugal switch, reduces motor size, weight Created Date: 4/4/2018 10:47:30 PM

 

[jbaccell]

Tom,

Thanks so much, I did a search from my phone with those numbers and got bupkis! I appreciate you taking the time to help.

Joe

 

[SLK001]

Measure the resistance between the two terminals (disconnected) and report back.


OOPS! It's a REAL relay, not one of those PTC POSs.

 

[jbaccell]

Trying to find a replacement is a bit confusing for the uninformed like yours truly. If someone could point me in the right direction, I'd be most grateful.

Joe

 

[whitmore]

Sensata (formerly Klixon) products are not easily available retail; any 3CR-14x-18x item
will probably work fine, but the only EASY way to locate a onesie, is to look for official Milwaukee
repair parts in stock for your grinder.

Sadly, it took me a week or two to find a similar (for my refrigerator) start component,
because GE was out of stock on the repair part. Eventually a Whirlpool 'kit'
turned out to have the exact same part, but NOT advertised as a Sensata part
number, either by GE or Whirlpool.

I bought lots of ice for cooler chests for those weeks. Later, found the part as a clone
for an order of magnitude less cash, and bought a few spares (they're in the refrigerator snack
tray now).

 

[SLK001]

Trying to find a replacement is a bit confusing for the uninformed like yours truly. If someone could point me in the right direction, I'd be most grateful.

Joe

It looks like it just snaps apart. Probably just needs the contacts to be cleaned.

 

[jbaccell]

It looks like it just snaps apart. Probably just needs the contacts to be cleaned.

After reading your post I ran into the garage to see if I could open it up. No joy, I attached another photo and I believe where the winding is wrapped, both halves are connected held in place by the winding.

I appreciate your input.

Joe

 

[SLK001]

After reading your post I ran into the garage to see if I could open it up.

I would bet that the relay is stuck (contacts welded). I would take a Dremel thin kerf saw and cut the plastic at the seam line on the side with the two male push on terminals (just on the three exposed sides), then delicately pry the part open enough to examine and possibly free the contacts. Once done, take a soldering iron and "weld" it back together.

It's busted, so what do you have to lose.

 

[jbaccell]

I would bet that the relay is stuck (contacts welded). I would take a Dremel thin kerf saw and cut the plastic at the seam line on the side with the two male push on terminals (just on the three exposed sides), then delicately pry the part open enough to examine and possibly free the contacts. Once done, take a soldering iron and "weld" it back together.

It's busted, so what do you have to lose.

Thanks so much, I will most certainly give it a try. Like you said, it’s already broken, I have nothing to lose.

Thanks again,

Joe