| SEQUENCE OF OPERATION |
Cooling | Heating |
The following sequences of operation are based on using a standard
WITH POWER TO UNIT AND THERMOSTAT IN COOLING MODE.
1.If the fan switch on the thermostat is in the “ON” position, the 24 volts at “G” will energize the “K1" relay on the fan control board, close the ”K1" relay contacts, and energize the indoor blower motor. If the fan switch is in the “AUTO” position, the blower will operate only when there is a call for cooling by the thermostat.
2.On a call for cooling, the thermostat will send 24 volts to “Y” on the fan control board. The 24 volt signal will energize contactor “M1", and power will be supplied to the compres- sor and outdoor fan motor. If the fan switch on the thermo- stat is on the ”AUTO" position, the thermostat will also send a 24 volt signal to “G” on the fan control board and the in- door blower will operate as indicated in step 1.
3.When the demand for cooling has been satisfied, the “M1" contactor will be
60 second delay, the “K1" relay will open and de- energize the indoor blower motor,
TABLE 13 - THERMOSTAT SIGNALS (SINGLE PHASE UNITS)
WITH POWER TO UNIT AND THERMOSTAT IN HEATING MODE.
1.If the fan switch on the thermostat is in the “ON” position, the 24 volts at “G” will energize the “K1" relay contacts, and energize the indoor blower motor. If the fan switch on the thermostat is in the ”AUTO" position, the blower will oper- ate only when there is a call for heating by the thermostat.
2.On a call for heating, the thermostat will send 24 volts to “W1" on the fan control board. The 24 volts signal will ener- gize relay ”K2" on the fan control board, and the first stage of electric heat will be energized.
3.When the heating demand is satisfied, the electric heat will be
Please refer to Table 13 and 14 for more information.
SIGNAL | STATE | |
“G” | ON | |
OFF | ||
| ||
“G” | ON | |
| ||
“Y” | OFF | |
| ||
| ON | |
“G” |
| |
“W1" |
| |
| OFF | |
| ON | |
“G” |
| |
“W1" |
| |
”W2" |
| |
| OFF | |
|
|
BOARD FUNCTION
FAN INSTANT ON
FAN INSTANT OFF
FAN INSTANT ON
COMPRESSOR AND OUTDOOR FAN INSTANT ON
COMPRESSOR AND OUTDOOR FAN INSTANT OFF FAN 60 SECOND DELAY OFF
FAN INSTANT ON1
HEATER BANK 1 ELEC. HEAT INSTANT ON
HEATER1BANK 1 ELEC. HEAT INSTANT OFF FAN 5 SECOND DELAY OFF
FAN INSTANT ON
HEATER BANK 1 ELEC. HEAT INSTANT ON
HEATER BANK 2 ELEC. HEAT 10 SECOND DELAY ON HEATER BANK 3 ELEC. HEAT 20 SECOND DELAY ON
HEATER BANK 1 ELEC. HEAT INSTANT OFF HEATER BANK 2 ELEC. HEAT 
2SECOND DELAY ON HEATER BANK 3 ELEC. HEAT 1 SECOND DELAY ON FAN 6
2SECOND DELAY OFF
SIGNAL | STATE |
ON
“W1"
OFF
ON
”W2"
OFF
ON
“W1"
”W2"
OFF
BOARD FUNCTION1
FAN INSTANT ON
HEATER BANK 1 ELEC. HEAT INSTANT ON
HEATER BANK 1 ELEC. HEAT INSTANT OFF FAN 5 SECOND DELAY OFF
FAN INSTANT ON1
HEATER BANK 1 ELEC. HEAT SEC. DELAY OFF HEATER1BANK 2 ELEC. HEAT INSTANT ON
HEATER BANK 1 ELEC. HEAT 2SEC. DELAY OFF HEATER BANK 2 ELEC. HEAT INSTANT OFF FAN 5 SECOND DELAY OFF
FAN INSTANT ON
HEATER BANK 1 ELEC. HEAT INSTANT ON
HEATER BANK 2 ELEC. HEAT 10 SECOND DELAY ON HEATER BANK 3 ELEC. HEAT 20 SECOND DELAY ON
STAGE 1 ELEC. HEAT INSTANT OFF
HEATER BANK 2 ELEC. HEAT 
2SECOND DELAY ON HEATER BANK 3 ELEC. HEAT 1 SECOND DELAY ON FAN 6
2SECOND DELAY OFF
Unitary Products Group | 11 |