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FIGURE 5: UNITED TECHNOLOGIES 1168-1 ECM TAP BOARD
(POF1HD140AVFA and POF1HD091AVFA)
1168-1 ELECTRONIC FAN TIMER BOARD (EFT) DETAILED SEQUENCE OF OPERATION
Thermostat Input LEDs (LED1-5, LED8)
Six green LEDs are placed behind their respective thermostat connections (Y1, Y/Y2, G, DH, O, and W) and operate
whenever a call is present.
Thermostat calls for "W". The 24VAC input signal is passed to pin 2 of P1 and will drive the K1 relay that provides
dedicated contacts to the T-T input of the Oil Primary Control. Thermostat calls for cool "Y1". The 24VAC input
signal is passed to pin 6 of P1. Thermostat calls for fan "G". The 24VAC signal is passed to pin 15 of P1.
Thermostat calls for dehumidification "DH". The 24VAC input signal is passed to pin 10 of P1. Thermostat calls
for reversing valve "O". The 24VAC input signal is passed to pin 9 of P1.
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