[AllanJ]

Now that you blew the speed control (or maybe the motor) from overvoltage, exactly what is wrong with it is unpredictable. Replacing the burnt capacitor is part of a trial and error process to getting it fixed. It is uncommon to use a more systematic approach to repairing devices such as speed controls because of the time needed to test individual components (like transistors).

If this is a DC motor, then the "speed control" has other functions in it too. Like converting AC to DC (rectifying). Fundamentally a DC motor speed control raises nd lowers the voltage. For a motor with two wires going into it you can substitute another brand of speed control that delivers the desired voltage with the needed number of amperes. Note that a motor draws more amperes as it starts up compared with running at normal speed.

I suggest that you immediately disconnect (at the panel or in the outlet box) that 120 volt receptacle that has 220 volts going to it.

 

[joed]

It is unlikely that the capacitor is the only problem with the controller.
As far as a controller off ebay you also need to look at the current or HP rating not just the voltage rating.

 

[korovyov]

Thanks hugely for your help. Just want to double-check- the controller should have amperage and HP ratings that exceed the specs of the motor, right?

For instance, this motor draws 90V, .35 amps and 1/30 HP. Will a controller that supplies 6 amps max. DC and .5 max. HP work? I'm assuming I want something that puts out more than the motor's specs, rather than less. Or am I wrong?

Thanks again!

 

[joed]

You are correct.

 

[nap]

I plugged it into what I thought was a 110v-20A circuit, switched it on, something in the speed control exploded after about a second, and the breaker tripped. Turned out that the socket I plugged into was running 220v - unlabeled, and through a regular-looking outlet. I re-plugged it into what I knew to be a 110v line, and the same thing happened.

!

a 240 volt receptacle, even if not labeled, is discernible from a 120 volt receptacle.. They are configured differently so you cannot accidentally plug the wrong plug into them.

If it looks like a 20 amp 120 volt recep and it is in fact a 240 volt circuit, I suggest you replace the incorrect receptacle with the correct receptacle.

 

[rjniles]

a 240 volt receptacle, even if not labeled, is discernible from a 120 volt receptacle.. They are configured differently so you cannot accidentally plug the wrong plug into them.

If it looks like a 20 amp 120 volt recep and it is in fact a 240 volt circuit, I suggest you replace the incorrect receptacle with the correct receptacle.

I had a similar situation in my house. In the closet in the master bath a water heater was wired with a plug and cord. It was a 20 amp receptacle and plug but was wired to a 240 volt circuit. Like many of the wiring issues I have found and corrected (but I did get the house cheap:thumbsup

Imagine if someone had plugged a hair dryer into that baby. Would have gotten real hot- for a second!