# Fog Machine Thermostats?



## cmk4425 (Oct 16, 2007)

I am rewiring my Chauvet 1300 to make it work like my other foggers with the basic thermostat, pump, and heater eliminating the board and letting it work with a normal timer. It is working now but the thermostat has a reset feature built into it and it keeps tripping after about 30 minutes and it turns the heater off until it is reset. Are all thermostats around the same setting because I was going to order one from American Dj but it would have to be a 1000watt or 1700watt thermostat. Also when the thermostat trips the timer is still on and keeps the pump running but when I reset the thermostat the timer works like normal again.


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## corey872 (Jan 10, 2010)

Sounds like you may be hitting a 'high limit' switch. This switch would act as sort of a 'watchdog' and cut power if the temperature goes too high... until you manually reset it. Another way to think about it is like a circuit breaker but this one functions on temperature instead of current draw.

Sounds like there might be some mis-wiring, too. Ideally, the limit switch would cut power to everything...pump, timer, heater, etc if it trips. It sounds like you may still be feeding power to the timer/pump, and only cutting power to the heater.

I would suspect all 'thermostats' trigger at about the same temperature - after all, fog fluid is pretty much universal to any machine, so they should work at the same temp. What will change is the wattage it can control... basically, how much current the contacts inside the switch can handle. I would purchase a thermostat rated at or above the wattage of your fogger.

One other thing you might consider, especially if you've moved any components during rewiring... you might try to move the 'sensing' portion of the thermostat back to the original location - or to a hotter part of the heat exchanger and/or move the limit switch back to its original location, too. If everything IS as it was, then maybe the thermostat is just broken, but if they've moved, it could be that the thermostat sensor is just seeing a lower temp and/or the limit switch is seeing a higher temp than it normally would.


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## cmk4425 (Oct 16, 2007)

I thought about it being miswired but I looked at the way it is wired and when the thermostat is working it feeds power to the heater and keeps the timer/trigger button from working until it heats up to the proper temp then the normally closed thermostat opens telling the timer that the heater is at the right temp. The problem is that when it cools down it isn't always closing the circuit to reheat the heater. Since the thermostat stays open the timer thinks that the heater is still hot and keeps going. I didn't move the thermostat I just rewired it. I checked and made a schematic of another fog machine to make sure everything was hooked up right. I think I may just have a bad thermostat. I think I will order the one for the 1700watt American Dj fogger to make sure it can handle the wattage. Thanks :biggrineton:


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