FIELD WIRING DIAGRAM FOR VARIABLE SPEED 2 STAGE FURNACE
2 STAGE HEATING
USING A 2 STAGE HEATING THERMOSTAT
1. Be sure power agrees with equipment nameplates.
2. Low voltage (24 volt wiring) to be No. 18 A.W.G. min.
3. Grounding of equipment must comply with local codes.
4. Set thermostat heat anticipator per unit wiring diagram.
5. These leads provide 115V. power for connection of humidifier
MAX. load 1.0 amp.
6. This wire is only for thermostats requiring connection to
transformer common terminal.
7. Continuous fan airflow can be increased by adding this jumper.
8. Set dip switches with power off per installation instructions
SEE NOTE 9
to set airflow and indoor fan off delays.
9. Optional humidistat is to be connected between R and BK. Factory
installed jumper R to BK on the circuit board must be cut if optional
humidistat is used. The jumper must also be cut when applying an airflow
command signal to the BK input such as with the variable speed single-zone
and multi-zone system controllers. On single speed cooling only/non-heat pump
systems, jumper Y to O for proper operation of the delay profiles and the humidistat.
For two compressor or two speed systems, jumper YLo to O.
TO 115 V 1 PH.,
60 HZ., POWER
From Dwg. B342025 Rev. 0