FIELD WIRING DIAGRAM FOR VARIABLE SPEED 2 STAGE FURNACE
1 STAGE HEATING
USING A 1 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. When a single stage heating thermostat without fan switch
is used, no wiring on "G" terminal is used.
7. W1 and W2 must be jumpered together for proper operation.
Second stage heat will begin 10 minutes after first stage.
8. Set dip switches with power off per installation instructions
SEE NOTE 11
to set airflow and indoor fan off delays.
9. Continuous fan airflow can be increased by adding this jumper.
10. This wire is only for thermostats requiring connection to
transformer common terminal.
11. 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.
FIELD ADDED JUMPER
W1 TO W2.
2ND STAGE WILL FIRE
10 MINUTES AFTER 1ST.
TO 115 V 1 PH.,
60 HZ., POWER
From Dwg. B342027 Rev. 0