3phase induction motor, P1 and P2 terminals for external control circuit

[Dsg319]

If one is not going to use the thermostat built in the motor to control (shut off there starter) , can P1 and P2 wires be capped off separately in the terminal box? I see no reason why the two would need to be tied together, as from the nameplate it looks like a NC set of contacts.

 

[don_resqcapt19]

You only need one cap if you cap them together....sometimes space is limited in the motor junction box.

 

[tom baker]

Yes, and the unavoidable, “but” I have seen motors if the t stat leads are not connected it voids the warranty. I would consider the cost, time, to replace the motor.

 

[Dsg319]

Yes, and the unavoidable, but I have seen motors if the t stat leads are not connected it voids the warranty. I would consider the cost, time, to replace the motor.

Luckily this is a bid-engineered job so will go back on the company we are working for, just on this job a couple days helping out on some intake fans. I’m sure they have some other source of overload protection figured already.
Honestly my first time seeing this on a 3ph induction motor though I’m sure it’s fairly common thing.

 

[Dsg319]

You only need one cap if you cap them together....sometimes space is limited in the motor junction box.

I thought about it but wasn’t sure, ended up being able to fit two caps comfortably though.

 

[petersonra]

why cap them at all?

 

[Dsg319]

why cap them at all?

Good point, force of habit I suppose. But really a waste of two fine wire nuts lol

 

[tom baker]

sensors are common in dry pit submersibles for seal failure alarms, also on hollow shaft motors