I have a 5 HP, 3 ph motor that was giving to me, chances are it is shorted, but I wanted to give it a shot here anyway.
When I check resistance from, T1-T4=1 ohm, T2-T5=1 ohm, T3-T6=1 ohm.
From here on out it gets foggy, I belive these windings are shorted togather. From, P4-P5=.3 ohm P4-P6=.2 ohm P4-T7=1 ohm P4-T8=1 ohm P4-T9=1 ohm.
Am I clear on this? I belive I should get readings simular to the previous group, not all interconnected. Thanks, Greg
Greg here is a quick scope of what and how a 3 phase motor is connected. This is of course in general which your 5hp 3phase motor should be.
A 3 phase dual voltage motor will have six windings and you will have nine leads coming from those windings. 1-4 is a winding 2-5 is a winding 3-6 is a winding
7-8-9 are leads from 3 more windings which are connected together on the other end to form the center of the wye connected motor. You normally cannot get to this connection as its down inside the windings and this is why 7-8-9 will always read together on an ohmmeter.As long as you have disconnected all the leads from one another you should not get a reading from one winding to another. I am not sure what you are calling P4-5-6. You should also check your motor from the leads to ground as well.
tim
The numbers are as the are numbered coming out of the motor. I have dissconnected all the leads in the junction box. I get continuity between the leads marked P4, P5, P5, T7, T8, & T9 with the leads separated. They are obviously joined or shorted togather. Greg
Do any of these terminals show a connection to the motor frame? If so, then it is almost certain that the motor is shorted. How many wires do you have here? You show T1 through T9 which sounds normal for a dual-voltage motor,then you also have P4 through P6. Does it actually have 12 wires?
Jon
Yes Greg
Is there a nameplate on this motor? Is it a dual speed motor? I really can't figure out what else the extra wires could be for. How come a P4 - P6, but no P1 - P3? Very confusing.
Jon
Single speed, 208/240-480 volt. I will take a look later to see what was connected. possibly some of the connections were NOT meant to come apart. I sniped all the connections to test the resistance. Greg
Wye-Delta for low voltage starting?
Nate
Greg -
Check page 6 of the PDF file
You may also be able to check the motor manufacturer's website for an installation manual for the motor. Baldor has manuals on their site, for example.
Doug, K8RFT
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