Motor starter heaters

[raven]

When sizing overloads ( heaters) for 3 phase starters, do you use the current on the nameplate of the motor for A( amps) or S.F.A. ?

 

[petersonra]

nameplate

 

[Besoeker3]

When sizing overloads ( heaters) for 3 phase starters, do you use the current on the nameplate of the motor for A( amps) or S.F.A. ?

Yes, nameplate is what I would use. And most thermal overloads I have come across have a range so the setting us adjustable.

 

[kwired]

Read instructions for your device. Often if a motor with a 1.0 SF you must use 90% of nameplate as the device and selection table or setting was designed for use with 1.15 SF.

 

[don_resqcapt19]

430.6(A)(2) Nameplate Values. Separate motor overload protection shall be based on the motor nameplate current rating.

 

[Bwas]

When sizing overloads ( heaters) for 3 phase starters, do you use the current on the nameplate of the motor for A( amps) or S.F.A. ?

i use motor FLA.

 

[Jraef]

Read instructions for your device. Often if a motor with a 1.0 SF you must use 90% of nameplate as the device and selection table or setting was designed for use with 1.15 SF.

Yes, RTFM. Some mfrs tell you to use the nameplate FLA exactly as shown, then adjust up for SF if required, some tell you that their selection tables are based on a 1.15SF and you adjust DOWN if the motor is 1.0 SF. You cannot make generalizations.