Electric window thermal cut out

[38rover]

Hi to all you electrical wizards out there can you help please my cut out has failed foune the one in the link on e bay will it do the job if so what temp would be best up tp 150c are available

http://www.ebay.co.uk/itm/Thermal-Thermostat-Temperature-Switch-NC-or-NO-Range-from-50-C-to-150-C-/151084725893

[marshman]

Hi to all you electrical wizards out there can you help please my cut out has failed foune the one in the link on e bay will it do the job if so what temp would be best up tp 150c are available

http://www.ebay.co.uk/itm/Thermal-Th...-/151084725893

This is not what you want. This will cut out (the switch will open) when whatever the switch is attached to gets to the defined temperature. They act as safety cutouts on fridge compressors and the like. You effectively want a thermal fuse. In order to get the correct rating you ideally need to know the stall current of the window winder and work from there.

You could do that by sticking a ammeter in where the cut out goes and wind the window up (or down) and see what the current rises to when the mechanism gets to the end of its travel. You can get "solid state" thermal fuses now (datasheet below):

http://www.farnell.com/datasheets/1864503.pdf

Not sure if the on resistance would be low enough for the windows though

Roger

[LAMBRETTLAD]

Replaced mine with a 15amp fuse ,works well

[38rover]

Thanks so much for the rapid replies

Excuse my ignorance on these matters but if you fit a fuse and the window button gets pushed for up when the window is up does it not blow the fuse ?
I understood the thermal cut out did just that when the window meets resistance it breaks the circuit then resets when button is released all via a bi metal spring.

[mallardstag]

Thanks so much for the rapid replies

Excuse my ignorance on these matters but if you fit a fuse and the window button gets pushed for up when the window is up does it not blow the fuse ?
I understood the thermal cut out did just that when the window meets resistance it breaks the circuit then resets when button is released all via a bi metal spring.

38Rover,

You're quite correct. The window circuit breaker will heat up when the window is stalled and will protect the stalled motor from overheating by breaking the circuit when it gets hot until it cools down again. It allows high current (as experienced when starting the motor or if the window is 'tight') for a short period but will break the circuit before the window motor or wiring is damaged. The breaker will then self-reset as it cools down.

A fuse will not perform this function and would have to be large enough to cope with the high start currents of the motor and thus not a suitable value for the circuit protection.

Simon

[V Mad]

I suspect a PPTC or Polyfuse eg this one below could be a potential replacement for the orignal part.

http://www.ebay.co.uk/itm/8A-8000mA-RGEF800-GF800-Resettable-Fuse-16V-PTC-Polyswitch-Polyfuse-12v-F27-/221698740304?pt=LH_DefaultDomain_3&hash=item339e465050

SAFETY NOTE: Using a non-standard electrical part without proper testing and approval carries a risk of fire !!!

[malc4d]

Or you could just get 1 from the Bros..........

http://www.rimmerbros.co.uk/Item--i-151244

[Staggard]

I just fitted a 10 amp blade fuse and holder. My windows close with the alarm and even both together I have not had a problem or a blown fuse.

[38rover]

Thank you all for your response