Those are Ranco thermostats - ON/OFF type controllers. ON/OFF means that there is a differential around the setpoint. Say your desired temp is 82 deg (setpoint).. when the sensor near the heater reads 82 deg, the output is OFF. If the differential is 3 deg, then the output to the heater won't go ON until the sensor reads 79 deg. Get it?



Proportional sends pulses of power to the heater to maintain the setpoint. There is no differential persay - the heater always maintains the setpoint temp.



Those Ranco thermostats have a rating of around 1650 Watts or so. So, if each cage uses say 40 watts of heater, you could run power to alot of cages from one thermostat. Yes, you would need to daisy-chain power strips.



There is only one sensor per each thermostat, so that sensor had better be on a cage that the heater is always plugged in and always working. Otherwise, if the sensor senses low temp in the cage (due to that heater being unplugged), the output to the other cages will be ON, and there is the potential for overheating those other cages. That is why you run TWO thermostats wired in series if you have lots of cages. The odds that two sensors in different cages will be in cages with unplugged heaters is way less than with only one.
-----
Mark

[ Show Entire Thread ]