Hi.
I saw a circuit that used a thermal fuse/thermal cutoff fuse(TCO)tied
to a metal oxide varistor(MOV)in order to cuttoff the current to the varistor,when the varistor
is reached to a specific temperature.And that is in order to prevent the varistor to burn.
The TCO comes in a different values of clearing temperature(the temperature that it cut the current).
What is the TCO clear temperature that should be chosen for a varistor?
In my case:a 7D391K(230VAC)varistor.In the varistor's datasheet of several brands they mentioned
only the operation temperature of the varistor(max?),which is about 125°C,but i didn't find a mention
to the combustion temperature of the varistor.
I would like to choose a temperature for the TCO to prevent the varistor to burn,but not a temperature that will everytime will open the TCO(permanently),just because the varistor temperature is rised alittle above its limit,while it doesn't burn.
Thanks.
I saw a circuit that used a thermal fuse/thermal cutoff fuse(TCO)tied
to a metal oxide varistor(MOV)in order to cuttoff the current to the varistor,when the varistor
is reached to a specific temperature.And that is in order to prevent the varistor to burn.
The TCO comes in a different values of clearing temperature(the temperature that it cut the current).
What is the TCO clear temperature that should be chosen for a varistor?
In my case:a 7D391K(230VAC)varistor.In the varistor's datasheet of several brands they mentioned
only the operation temperature of the varistor(max?),which is about 125°C,but i didn't find a mention
to the combustion temperature of the varistor.
I would like to choose a temperature for the TCO to prevent the varistor to burn,but not a temperature that will everytime will open the TCO(permanently),just because the varistor temperature is rised alittle above its limit,while it doesn't burn.
Thanks.