Warming cabinet fan cut out?

[whazza22]

Hi all,

I'm replacing a small fan used for a warming cabinet.

The faulty fan has some sort of cut out mounted on the housing but the new one doesn't.

Would this be a thermal cutout?

There is another cutout above the stat which I would of thought is the thermal cut out.

Please see pic below.

 

[ian.settle1]

Looks like a resettable thermal cutout, shold have checked these first as it could be this that is at fault and not the fan

 

[telectrix]

looking at that pic., there's some very hungry mice on site.

 

[grantr37]

a 2-dissimilar metal flexion alloy thermal cut out with a reset press by the looks of it, you might want to get a couple of nice new ones off ebay, about £4 each as far as I remember....check the old fan over, if the new one is there then just fit it and bin the old one...have a think about if the cut out can be fitted to the new casing, stick a new cutout there if it will rivet on, if the casing is awkward then as it's a throwaway part, you could get someone to put 2 tiny spots on the fixing plate(the metal flange on the cut out) to fix it to the casing....with some kind of thin welding wire... will take them 20 seconds to do it and will probably only take a fiver, if they will even ask for anything...

if you need any help to find the right cutout then drop me a PM

 

[Marvo]

It is either an over-temperature cutout or an over-current cutout or it might act as both.

Some fans don't need one because of their design. Especially with smaller fans, the impedance of the windings can sometimes be high enough to prevent dangerous lock-rotor currents and temperatures. UL standards require t<150C for a period of 360 hours under locked rotor conditions. If the motor design can't meet this spec ie the winding impedance is too low and LRA is too high then a thermal protector would be fitted.

Asalready mentioned it's worth checking the thermal protector before replacing the motor, it's not unusual for them to go permanent open circuit especially if they've been cycled a few times in their life.

 

[FrankUK]

What you are looking at is called a 'Klixon'
It is a temperature activated switch (thermostat)
If the new motor has inbuilt thermal protection, then you can just wire it in without worry. If the fan motor is rated in excess of 0.37kW, then you need to incorporate overload protection if you want to comply with the current edition of BS7671

 

[whazza22]

Thanks for everyone's input.

Managed to modify the new casing and fit the thermal cut out

 

[grantr37]

What you are looking at is called a 'Klixon'
It is a temperature activated switch (thermostat)
If the new motor has inbuilt thermal protection, then you can just wire it in without worry. If the fan motor is rated in excess of 0.37kW, then you need to incorporate overload protection if you want to comply with the current edition of BS7671

used in electric cookers and microwaves as well...