motor starter

[rippledipple]

Hi guys, I'm wiring a 1.5 hp roof power vent for a crematorium.My question is would that require
a separate motor starter since it gets really hot in there in the summer for added protection??? thx

 

[augie47]

Is the motor thermally protected ?

 

[petersonra]

Hi guys, I'm wiring a 1.5 hp roof power vent for a crematorium.My question is would that require
a separate motor starter since it gets really hot in there in the summer for added protection??? thx

how would a separate motor starter help?

 

[rippledipple]

Is the motor thermally protected ?

probably,its not installed yet

 

[rippledipple]

how would a separate motor starter help?

good question??

 

[rippledipple]

how would a separate motor starter help?

thought it might be too big to be controlled by a t stat??

 

[Jraef]

thought it might be too big to be controlled by a t stat??

That's likely the case, but it has nothing to do with temperature. Most t-stat contacts might be rated for 1/2HP at best, maybe 1/3HP, but switching a 1HP motor directly is typically beyond the capability of cheap little "pilot duty" contacts, like what you would find in a t-stat.

So as to whether or not you need a STARTER or just a CONTACTOR will depend on whether or not the motor is thermally protected. If it is, you can use a contactor, if not you must use a starter.

 

[rippledipple]

That's likely the case, but it has nothing to do with temperature. Most t-stat contacts might be rated for 1/2HP at best, maybe 1/3HP, but switching a 1HP motor directly is typically beyond the capability of cheap little "pilot duty" contacts, like what you would find in a t-stat.

So as to whether or not you need a STARTER or just a CONTACTOR will depend on whether or not the motor is thermally protected. If it is, you can use a contactor, if not you must use a starter.

thank you, Jraef

 

[kwired]

Hi guys, I'm wiring a 1.5 hp roof power vent for a crematorium.My question is would that require
a separate motor starter since it gets really hot in there in the summer for added protection??? thx

Is this just a room exhaust fan for the room where the crematorium is located? If so, the temp may be hot for you, but most likely is not really all that close to how hot the motor can operate. Plus if it is a motor located in the air stream that also keeps the motor cooler, even if it is exhausting 125 deg F air the motor will run hotter then that when fully loaded for long enough time.

Motor starter overload elements will only respond to motor current. If you want to shut down because of excess temperature in the motor you need thermal sensor of some sort inside the motor, whether it directly interrupts motor current or opens a control circuit for the motor.

 

[GoldDigger]

Motor starter overload elements will only respond to motor current. If you want to shut down because of excess temperature in the motor you need thermal sensor of some sort inside the motor, whether it directly interrupts motor current or opens a control circuit for the motor.

If the overloads are thermal type rather than solid state, won't they be sensitive to the ambient temperature at the location of the starter?
That may or may not track the ambient temperature at the motor.

 

[kwired]

If the overloads are thermal type rather than solid state, won't they be sensitive to the ambient temperature at the location of the starter?
That may or may not track the ambient temperature at the motor.

Correct.

 

[ptonsparky]

If the overloads are thermal type rather than solid state, won't they be sensitive to the ambient temperature at the location of the starter?
That may or may not track the ambient temperature at the motor.

One of the problems wrestled with for years. Motor on the roof but the MCC in a conditioned space.

 

[kwired]

One of the problems wrestled with for years. Motor on the roof but the MCC in a conditioned space.

Or even motor in the process area at a much higher ambient then where the MCC is.