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ST9120U Universal Electronic Fan Timers
APPLICATION
The ST9120U Universal Electronic Fan Timers integrate control of all combustion blower and circulating fan operations in a gas warm air appliance. This control is the central wiring point for most of the electrical components in the furnace. The basic purposes of the ST9120U are to monitor the thermostat for heat, cool and fan demands, run the induced draft blower motor and run a circulating fan (up to two speeds) as required. The electronic fan timers also monitor limit switch strings and energize separate ignition control systems through spst pressure switches. The ST9120U can replace any ST9101 or ST9120 listed in Table 2 below.
ST9120U Datasheet
