Temperature rating for KSD301 thermal switch used in fog machine

[Samuel43]

Hi,
So I was attempting to repair this fog machine I've had for a number of years and figured out in the process that the thermal switch used to control the whole show was probably bad as it should be reading about 0.05 Ohms but when I have it disconnected my meter reads anywhere from 0.2 to several hundred Ohms.  The issue I'm having is knowing what the switching temperature of the KSD301 switch in my fog machine is.  I attempted to contact the manufacturer and they weren't helpful.  On the bottom of the switch there are the markings "B240" and "CM".  Would this suggest the switching temperature is 240'C? 
Thanks

[floobydust]

KSD-301 series is a bimetallic thermostat.
This was talked about here: https://www.eevblog.com/forum/repair/replacing-thermal-fuse-in-a-fog-machine
Antari F-80Z uses 220°C and Big Clive mentioned 200-300°C operating. So your 240°C marking is reasonable.

[fzabkar]

I couldn't believe the number of variations in the part marking that turned up in my Google Image search.

This one appears to be a 110C version (marked "B110 PM"):

https://www.ebay.com/itm/352623366855

[Samuel43]

Okay.  I think I may try finding a 240c KSD301 then.  My only other concern is that my fog machine contains a thermal fuse that is marked with 133'C and I really don't want to blow that if I choose the wrong thermostat.  But it is placed a little bit away from the heater and has some insulation so I guess it works for this design of fog machine.  Any chance the 240 means 240'F, or am I just way overthinking this.

[floobydust]

These come in many different mechanical and electrical configurations, literally 100's and everybody and their dog is making them, with their own part numbering and labelling scheme.
The main danger is confusing the thermostat with the high temp safety limit switch. To make it worse, they can be located in different places e.g. one at the heater or enclosure bottom, another at the fluid exit. One keeps the heat right and another prevents meltdown.
240°C = 464°F