Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

3-phase Motor – High Winding Resistance and Overcurrent Fault?

Status
Not open for further replies.
E

elektrotechnik

Junior Member level 1
Joined
Jul 31, 2013
Messages
19
Helped
0
Reputation
0
Reaction score
0
Trophy points
1
Activity points
198
Hi all,

I am testing a variety of 3-phase (wye) motors. In my testing, one of my motors is triggering an overcurrent fault. I checked the resistance of the windings (between 1 and 2, 2 and 3, and 1 and 3) and the winding resistance is actually higher than the specification. The winding resistance is also higher than the other motors that I tested.

I’d be violating Ohm’s Law if I said the overcurrent fault was triggered by the high winding resistance. Could an overcurrent fault actually be triggered by this high winding resistance causing some other issue? Is there anything else on the motor that I should be measuring or comparing to the other motors?
 

The impedance of the winding is greater than just the DC resistance and maybe you've got a defective winding. When the motor is running there is less current flowing than when it's stalled (lock rotor current). How much difference in resistance is there between motors? Maybe the motor was wound for 240V and you're running it at 480V?
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top