I built a hot box and purchased a limt switch form bighams.Its a 150-180 limit. I have three 100 watt bulbs. I wired it so the limit would shut all the bulbs off, but found the temp. dropped rather quickly. So I changed the wiring so only the middle bulb will shut off.While all three bulbs are on it reaches 160 degrees,then turns the middle bulb off at 160 but it does not come back on until the temp. drops to 115 degrees.Is this normal or do I need a faster limit? The box is insulated so the temp. does drop very fast but I dont know if it is to drastic of a change.Thanks for the help.
The temp drop is normal with a snap disk thermometer. It wont cause problems it just takes longer to cure a bow. It helps to mount the thermometer toward the bottom of the oven, away from the lights or install a small fan.
Thanks, I do have the thermometer in the lower part of the box (height were riser will be) but I dont have a fan.Again thanks for the help this will be my first attempt.Is there a better limt to use?
If you dont want to go with a solid state temp control you might find a snap disk thermometer with a smaller on/off window, such as on at 170 off at 180. You can find them at appliance stores, they are used in dryers and furnaces.
I used 5 bulbs, I think the thermostat controls three of them. I bought it from Binghams also, and it seems to cycle between 170 and 180. Seems weird to get one that is 115 to 160, that's a huge range. You might contact Binghams about it.