US Electronics thermal protectors work like thermostats to control the temperature and as Hi-limits to limit the temperature. These have normally closed contacts which will open on temperature reaching the set point and will close on temperature dropping down to a safe point. These are extensively used in small appliances and for motor overload protection. The motor overload protectors also trip on current overload conditions.

US Electronics thermal fuses are used as Hi-limits to limit the temperature. These have normally closed contacts which will open on temperature reaching the set point. These are one-time devices like fuses and cannot be reset but must be replaced. Their cut off temperature must be higher than the normal operating temperature to prevent nuisance tripping. These are extensively used in small appliances and for motor overload protection. The motor overload protectors also trip on current overload conditions.