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connections AC motor ? Answered

Dear  All...
I have an Ac motor
FASCO  no. 7160-0276   3wire:
 Back ( com.) Red (start) white(run)
 But unfortunate can not find this model on internet, So Could you help me to connection this motor with schema if must used with capacitor please tell me how value (mf)of  the capacitor Please.Thank you very much for your time.


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Jack A Lopez
Jack A Lopez

Answer 5 years ago

I also could not find any documentation for this motor, but I have some suggestions.

I am guessing this motor is wired like the drawing I have attached. It has two windings, a (R)un winding and a (S)tart winding, and those two windings are connected to each other at the terminal called (C)ommon.

When starting the motor, both the (R)un winding and (S)tart winding are energized. Then, once the motor is spinning, the (S)tart winding is disconnected, and only the (R)un winding needs to stay powered, to keep the motor running.

This section,


of the Wikipedia article on AC motors, sort of says the same thing, but it also mentions the trick with a centrifugal switch (which senses when the motor is turning full speed and switches off the start winding automatically), and also it mentions that sometimes, sometimes not, a capacitor is wired in series with this start winding.

Anyway, the circuit diagram I have attached is intended for testing purposes. Also I have attached a picture of what I imagine the physical testing-purposes switch box might look like. Basically all I have done here is put a switch in series with each winding. The reason I have put a rubber band on the switch for the (S)tart winding is because that switch is only intended to be on momentarily. It should only take a few seconds or so for the motor to spin up. Then when I take my hand away, the rubber band naturally pulls that switch to the "off" position, turning off the (S)tart winding.

Also it *might* turn out to be possible to start this motor, without using the (S)tart winding, just by mechanically turning the shaft by hand, just to get spinning, then turning on the the (R)un winding.

By the way, both these methods: turning the motor by hand, and the light switch with the rubber band, may be inconvenient ways to start an electric motor.

I think the way this motor, was intended to be started is using a circuit with a momentary button, labeled "start", in series with the (S)tart winding, and a relay that turns on the (R)un winding. Such a circuit also typically includes a "stop" button for to break the current to the relay, to turn the motor off.

I am guessing, this circuit with relay and start/stop buttons, is what Jay Smith, from Regal Beloit, was thinking of when he wrote, "The pictured motor 71606276 is a split-phase design and not a capacitor run. The motor requires an external relay to start.", in that discussion from like two years ago.