Small motor overloads. 430.32

[Isaiah]

I’ve got a 120V, damper motor - under 1Hp automatically started - but the vendor doesn’t include any info on the motor as far as thermal overload protection, etc
It’s fed from a 20A 1/P CB, lighting Panelboard.
Do I need to add thermal overloads or can I assume the vendor has protected this small motor?


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[LarryFine]

Got a motor type and/or a part/catalog number?

 

[Isaiah]

Got a motor type and/or a part/catalog number?

The vendor doesn’t include anything on the motor but it’s called a “motorized damper”


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[LarryFine]

It's probably impedance-protected, meaning it pulls too little current to be damaged even if stalled.

 

[Isaiah]

It's probably impedance-protected, meaning it pulls too little current to be damaged even if stalled.

I think you’re right


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[ptonsparky]

I have some small motorized dampers that stay energized to hold them open. Spring return.

 

[Isaiah]

I have some small motorized dampers that stay energized to hold them open. Spring return.

They don’t need overloads?


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[MTW]

Typically electronic or impedance protected depending on model.

https://www.belimo.com/mam/general-documents/datasheets/en-us/belimo_TFB120_datasheet_en-us.pdf

 

[Isaiah]

Typically electronic or impedance protected depending on model.

https://www.belimo.com/mam/general-documents/datasheets/en-us/belimo_TFB120_datasheet_en-us.pdf

Excellent thanks !


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[texie]

They don’t need overloads?


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No, as being impedance protected means the motor will not draw excessive current even when stalled. Another example would be a bath fan.

 

[Isaiah]

No, as being impedance protected means the motor will not draw excessive current even when stalled. Another example would be a bath fan.

If it’s “spring return” it’s also not required right?


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[ptonsparky]

Correct