Thermostatically controlled power draft motor cooling system

摘要

A variable speed power flue ventilator with a thermostatically controlled motor cooling system. The thermostatically controlled cooling system employs an auxiliary motor cooling fan separate from the fan used by the power ventilator to extract exhaust gases. A thermostatic sensor switch actuates the motor cooling fan whenever the temperature in the exhaust fan motor housing rises to a preset value. The cooling fan then draws cool ambient air through the motor housing until the enclosed housing area reaches a second lower, preset temperature at which point the cooling fan is shut off by the thermostat.