how to build a reverse power relay??

Thread Starter

whitearrow

Joined Jan 6, 2009
13
hi can anyone help me in building a reverse power relay for a 3 phase motor?? the voltage applied to it is 40V 50Hz. has any one got a simple circuit?? what ic's must i use to begin with??
 
Last edited:

beenthere

Joined Apr 20, 2004
15,808
To reverse a 3 phase motor, you have to swap two phases. The procedure is to open the main contactor and then use another two pole double throw relay to do the phase reversal. It's also a good idea to wait for the motor to stop turning before starting in reverse.
 

Thread Starter

whitearrow

Joined Jan 6, 2009
13
i'am sorry, the reverse power relay is needed for a 3 phase 40V 50Hz generator not a motor. it is used to prevent from motoring.
 

beenthere

Joined Apr 20, 2004
15,808
That puts me out of my depth - someone should be able to make suggestions, though.
 

floomdoggle

Joined Sep 1, 2008
217
Hey Whitearrow,
Tou probably need a diode between the generator and power supply.
Explain a little bit more and these guys can help.
Dan
 

eblc1388

Joined Nov 28, 2008
1,543
i'am sorry, the reverse power relay is needed for a 3 phase 40V 50Hz generator not a motor. it is used to prevent from motoring.
Reverse power protection is nearly standard on all generators.

As leftyretro has said, you'll need to buy one if one is not fitted on the generator. It is quite expensive though.
 

Thread Starter

whitearrow

Joined Jan 6, 2009
13
the problem is that i have to do this reverse power relay myself and i don't know exactly what parameters to measure to do this.
 
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