DC drive sudden high bridge temp
DC drive sudden high bridge temp
(OP)
2 different drives are experiencing higher than normal bridge temps after a 6 month shutdown. Both are ABB DCS 500's. One is for a 40 hp motor, the other is for 2 75hp with the armatures in series. They are both way under FLA. Before the shutdown these drives both had bridge temps under 30C. Within hours of startup we were seeing temps around 60C. We're using portable ac units right now to keep the temps down to around 35, but would like to remove them at some point. Both drives are supplied by the same 4160/480 delta/wye and they each have their own 480/480 delt/wye isolation transformers. Voltage measurements are 485 l-l and 295 320 295 l-g off the isolation transformer, and normal before it. Is there a common component that may be failing from sitting too long?





RE: DC drive sudden high bridge temp
You can de-power it all and re-check any mounting fasteners. That's likely the only thing that changed in months. If something had failed I'd expect you'd be seeing other symptom.
Keith Cress
kcress - http://www.flaminsystems.com
RE: DC drive sudden high bridge temp
Have you looked at the incoming current, both in magnitude and harmonic content?
RE: DC drive sudden high bridge temp
RE: DC drive sudden high bridge temp
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If we learn from our mistakes I'm getting a great education!
RE: DC drive sudden high bridge temp
Second, I can't imagine the drives supplying any significant energy to the motor and remaining at 30 degrees C. Shucks, in most cases the ambient is that hot. Either something is wrong with the 30 degree C figure or the motors weren't doing any work before and are doing a little more now.
I don't think you have a problem.
RE: DC drive sudden high bridge temp
As far as work being done, the 40hp unit fluctuates between 6-14A with plenty of reserve in case of trouble, and the series wired 75's average around 80-120A. Loads between both kiln lines are very close, as was the temperature before the shutdown. We check bridge temp on our daily walk arounds. Keeping the temp down is important for us. ABB advised us that the drives would last multiples of years longer if we could keep the bridge temp under 35.
RE: DC drive sudden high bridge temp
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If we learn from our mistakes I'm getting a great education!
RE: DC drive sudden high bridge temp
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: DC drive sudden high bridge temp
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If we learn from our mistakes I'm getting a great education!