Motor capacitor(s)

[theoldwizard1]

My buddy picked up and old Craftsman tables saw (probably late 50s/early 60s) for "a song" at an auction. When he got it hoame and finally plugged it in, the motor trips the overload when it tries to spin up. Remove the belt and it spins up no problem. I am guessing it is 120V and probably between 1/2 and 1 hp.

We have not cracked ope the case yet, but I think most electric motors in that range have 2 capacitors, a start capacitor and a run capacitor, or possibly a dual capacitor.

What is a SWAG number for the cost of a motor capacitor and any suggestion on where to buy one ?

 

[aircommuter]

$15-30, try W.W. Grainger

 

[ihateminimumwage]

We order all of ours through Grainger for Cap regulated generators. I think the most expensive we've had to order was maybe $70, but it was about the size of an old Ford ignition coil.

 

[Mr. T]

If you know what you need Allied electronics or Zoro will be cheaper than Grainger.

 

[exmaxima1]

My buddy picked up and old Craftsman tables saw (probably late 50s/early 60s) for "a song" at an auction. When he got it hoame and finally plugged it in, the motor trips the overload when it tries to spin up. Remove the belt and it spins up no problem. I am guessing it is 120V and probably between 1/2 and 1 hp.

We have not cracked ope the case yet, but I think most electric motors in that range have 2 capacitors, a start capacitor and a run capacitor, or possibly a dual capacitor.

What is a SWAG number for the cost of a motor capacitor and any suggestion on where to buy one ?

Start cap only, no run capacitors. Some of the older CM motors have a flat rectangular box capacitor in the base. Later models will have a cylindrical capacitor inside the end bell---a total PIA to get at it without breaking something...

 

[cgrutt]

I recently bought some caps for an air compressor online and they were very inexpensive (under $10 shipped). Forgot the name of the place I bought them from though. Well it turns out the caps weren't the problem so I have a spare set. I'm away for weekend but will check size for you when I get back next week if you want. You can have them if they fit. I'll even cover the shipping...

Let me know. If you need them right away, they're really not that expensive and usually readily available. I've also bought caps from Zoro which has a big selection.

 

[theoldwizard1]

Start cap only, no run capacitors.

Wasn't certain, but that was what I was guessing.

Some of the older CM motors have a flat rectangular box capacitor in the base. Later models will have a cylindrical capacitor inside the end bell---a total PIA to get at it without breaking something...

As I said, this is from the late 50s so I will make certain to look in the base before dis-assembly. I know sometime the contacts on the centrifugal switch need to be cleaned, but this saw looks like it was never used much.

 

[Rookie2]

http://www.surpluscenter.com/Electrical/Capacitors/

 

[Mark in Indiana]

I've bought capacitors from Amazon for anywhere from $7 to $17.

 

[My Old Tools]

Sounds like the centrifugal start switch is hung. Pretty common. They get packed with sawdust.

 

[highcarbon]

if a grainger isnt close by try an air conditioner/refrigeration parts supply house

 

[theoldwizard1]

Sounds like the centrifugal start switch is hung. Pretty common. They get packed with sawdust.

Thanks ! Will definitely check that.

 

[bmwrd0]

" When he got it hoame and finally plugged it in, the motor trips the overload when it tries to spin up. Remove the belt and it spins up no problem."

So, the motor will run without the belt attached? If that is the case, it isn't the capacitor.