Enclosure Fan Protection Recommendation Needed

[110.14(D)]

I have a 230 VAC 0.07 Amp enclosure exhaust fan, and need advice on protection device selection and calculation. Any advantage of fuse vs breaker?

 

[retirede]

I have a 230 VAC 0.07 Amp enclosure exhaust fan, and need advice on protection device selection and calculation. Any advantage of fuse vs breaker?

Many of these small fans are impedance protected, in which case you needn’t provide further overload protection.

 

[Ingenieur]

a small 0.75 A fuse is enough, if anything is even required

 

[110.14(D)]

Thanks for the guidance, I thought there was an actual code based calculation for this, but wasn't sure if applying Table 430.52 would be right for this device. Found a 0.5A 2 pole mini breaker that should work for short circuit protection.

 

[kwired]

Thanks for the guidance, I thought there was an actual code based calculation for this, but wasn't sure if applying Table 430.52 would be right for this device. Found a 0.5A 2 pole mini breaker that should work for short circuit protection.

IMO a 15 amp breaker is just as effective for short circuit protection. As mentioned such fans are almost always impedance protected. This protects your wiring from overcurrent. Most any fuse or breaker you use that is 15 amps or less protects your wiring from short circuits. If the motor has failed it needs replaced anyway - what is the point of selecting a device to protect the motor in this case?

That 2 pole mini breaker probably cost same or more then the fan it is protecting. As long as the wiring is protected from overloading and possibly starting a fire that is all that is really necessary.

 

[110.14(D)]

20A branch circuit supplying panel. Fan $51.00, breaker ebay surplus $8.60.

 

[kwired]

20A branch circuit supplying panel. Fan $51.00, breaker ebay surplus $8.60.

Ok, but if the fan has failed, it still cost $51.00 to replace it whether it trips a breaker or not

Slightly off topic, I just ordered a couple similar fans for cooling of a VFD to replace a failing original fan. Searched for model number and got price ranges from about $6.00 to $75.00 for what is presumably same item.