Motor Temperature Rating
Motor Temperature Rating
(OP)
Hello,
I have a motor with a temperature rating on the nameplate that says:
AMB 50 Degrees C
Is this the maximum allowed temperature rise above ambient or is this the maximum allowed temperature of the motor?
No other termperature reference is on the motor.
This is an older motor from the late 1960's.
Thanks for any help.
Kingjoey
I have a motor with a temperature rating on the nameplate that says:
AMB 50 Degrees C
Is this the maximum allowed temperature rise above ambient or is this the maximum allowed temperature of the motor?
No other termperature reference is on the motor.
This is an older motor from the late 1960's.
Thanks for any help.
Kingjoey





RE: Motor Temperature Rating
RE: Motor Temperature Rating
Another question - The motor has class F insulation. Does this mean that the motor windings can be operated at a 105 deg C rise above a 50 deg C ambient since class F insulation is capable of 155 deg C?
Thanks again.
Kingjoey
RE: Motor Temperature Rating
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: Motor Temperature Rating
I quess that my basic question is:
How hot can I operate this motor?
I am using an infrared device to measure the outside temperature of the motor. I hope that the readings are representative of the winding temperatures.
Thanks again,
KingJoey
RE: Motor Temperature Rating
The big problem is that it is highly unlikely that anyone can tell you exactly what the case temperature will be when the windings are close to 155C. I doubt any motor manufacturer would even tell you.
RE: Motor Temperature Rating
The max allowable hot spot temp is 155 deg C. That is the key figure. Everything else is worked out backwards from there. With a 10 deg hot spot allowance, that gives an average temperature by resistance of 145 deg C. With 50 deg C ambient that gives an average temp rise of 95 deg C.
The 50 deg C ambient rating means that a 100 hp motor can operate at 100 hp in a 50 deg C ambient. For a normal 40 deg C motor, the 100 hp rating would have be reduced at the 50 deg C ambient.
RE: Motor Temperature Rating
RE: Motor Temperature Rating