Heater interlock control for air conditioning system

摘要

An air conditioning apparatus, including an electric motor driven blower for circulating air through a cabinet, also includes one or more electric heating elements and a system controller operable to control energization of the heating elements and the blower motor at predetermined operating conditions by way of suitable relay or control elements. The system includes a heating interlock relay to prevent energization of the one or more heating elements if the blower motor is inoperable, operating at other than a predetermined range of speeds or the system controller detects a malfunctioning heating element control relay or the like.

主权项

1. An air conditioning system comprising:
an air blower including an electric blower motor for propelling air from an air inlet in a cabinet to an air outlet; at least one electric heating element disposed in an air flowstream propelled by said air blower through said cabinet; a heater interlock operatively connected to said at least one electric heating element and operable to control energization thereof; at least one heater relay in communication with said heater interlock; and a system controller operable to communicate control signals for controlling operation of one or more components of the air conditioning system, said control signals being based on status signals indicative of one or more operating conditions corresponding to at least one of said air blower, said at least one electric heating element, said heater interlock, and said at least one heater relay, wherein said status signals include fault signals indicative of faulty operating conditions associated with at least one of said heater interlock or said at least one heater relay; wherein said system controller communicates a control signal instructing said heater interlock to prevent energization of said at least one electric heating element in response to occurrence of both (1) receiving a status signal indicating said electric blower motor is operating at a speed outside a predetermined range of speeds and (2) said at least one heater relay indicating a faulty operating condition.