Our small concrete mixer blew the start cap so we have to spin it by hand to
get it going. It is a 110 volt motor, probably 1/3 hp. It uses a 40 mfd, 400
volt cap. The closest Grainger has that I can find is a 43-50 mfd, 250 volt.
Would that work, or do we need to get a 40 mfd? What about the voltage rating,
is 250 ok since this is a 110 volt motor, or do I need to stick to a 400 volt
rating?

--
Dennis

The tolerances for start caps is uneven. Something like - 20 % plus
100%. I don't think you will have any problem with using the 43-50
mfd 250 volt. If you rewired the motor for 240 volt operation, it
should still be okay. Typically the start winding is always used on
120 volts.

Dan

In article .com,
says...

The tolerances for start caps is uneven. Something like - 20 % plus
100%. I don't think you will have any problem with using the 43-50
mfd 250 volt. If you rewired the motor for 240 volt operation, it
should still be okay. Typically the start winding is always used on
120 volts.

Thanks. I went down to Surplus Electronics near me and found a 40 mfd 250 v cap
for. I also discovered the switch on the mixer had gone bad so I picked up a
weatherproof 20 amp switch. Everything works fine again, only ten bucks spent.

--
Dennis

According to DT :
In article .com,
says...

The tolerances for start caps is uneven. Something like - 20 % plus
100%. I don't think you will have any problem with using the 43-50
mfd 250 volt. If you rewired the motor for 240 volt operation, it
should still be okay. Typically the start winding is always used on
120 volts.

Thanks. I went down to Surplus Electronics near me and found a 40 mfd 250 v cap
for.

Make sure that it is *marked* as a start capacitor. 40 uf 250V
sounds like a common DC rating, and a surplus electronics place is more
likely to have DC caps than the AC rated ones needed for motor starting
duty.

If it is DC rated -- you'll be lucky if it lasts a single start.

I also discovered the switch on the mixer had gone bad so I picked up a
weatherproof 20 amp switch. Everything works fine again, only ten bucks spent.

O.K. So you *did* get a motor starting cap, not a DC one.
Good.

BTW I find it good practice to have a couple of spares on hand,
since they tend to go out in the middle of a project just late
enough into a weekend so you can't buy replacements until
Monday. :-)

Enjoy,
DoN.
--
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