DC Motor Air Switch question
DC Motor Air Switch question
(OP)
I have a 40hp DC Motor on a Digital Drive and I would like alarm maybe with a flashing light, not shutdown if the Motor Blower is not operating. This Drive is stand alone not connected to PLC or DCS. The Motor Thermal Switch is going back to the Drive but I would like to catch the problem before the motor heats. I was considering an air Switch with contacts to operate a flashing light to get maintenance to address the Motor Blower before the Process is effected. But I am not sure about the reliability of air switches for this small of an application. Has any one have similar experience?





RE: DC Motor Air Switch question
Bill
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"Why not the best?"
Jimmy Carter
RE: DC Motor Air Switch question
RE: DC Motor Air Switch question
RE: DC Motor Air Switch question
I understand that the motor already has a temperature switch. BearB wants an alarm that will act before the motor heats.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: DC Motor Air Switch question
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RE: DC Motor Air Switch question
Of course, you must be already having a mechanism of starting the dc motor along (or better, before) with the fan motor.
RE: DC Motor Air Switch question
Keith Cress
kcress - http://www.flaminsystems.com
RE: DC Motor Air Switch question
You could also use a cheaper Dwyer switch to monitor the fan pressure.
Often it's not the switch that fails but a bad installation detail.
I recommend that whatever switch you use, verify the switches operation by using it's non activated state as a permissive in the fan start circuit, if it doesn't change state when the fan stops you don't have permission to start it again and if it doesn't activate when you start the fan the DC motor wont start. If they both start together you may need a timer to bypass the switch for a few seconds.
Regards
Roy
RE: DC Motor Air Switch question