flyrotary@lancaironline.net Mailing List Archive

Will you reset the pump controls after each shut-down (overheat) or do you want to restart on cool-down?

Perhaps you would like a restart only when the pump is needed. If your pump is a centrifugal and the load fluid will flow through it you can have a sail switch to restart the pump. A pressure switch on the exit will keep it running until the sail switch drops out for lack of flow. Or a Klicks-on shuts it off. All of this requires a three phase relay.

Most 3 phase motors have a 30 to 60 degree temp rise when running. That would be 60 degrees above ambient temp and is normal for that pump motor. See data plate.

A Klickson will open at or near the specified temp but will reset just below that temp. Various types will allow

different delay times. The pumps are cooled by ambient air and the media being pumped.

An engineer at the motor builder can send you a drawing of a typical control circuit, or even supply one.

Using a pump overheat to trip the circuit seems to me to shorten pump life.

But, I could be completely wrong. Lynn E. Hanover

In a message dated 8/12/2019 10:37:29 AM Eastern Standard Time, flyrotary@lancaironline.net writes:

Gents, Nothing to do with flying, but you may be able to assist. I
have numerous trash pumps that need a thermocouple linked to a 3 Phase
cutout. Yes I can buy a stock unit for over $3000 each which to me is
as hot as the pump can get. All I need is a switch that will cut out
the pump (power) when it overheats due to dry running. If it doesn't
the pump then self destructs and $6000 later I am ready to go again.
I can however get replacement pumps from china for $500 but without the
cutout.

So simple heat sensor switch that will go open at preset temp high
setting, say 90 - 100 degrees C . Possibly single phase to disconect 3
phase contactor. Suggestions??>

Neil.