Specifications

Manual 2100-590C
Page 39 of 67
32. INDOOR BLOWER OPERATION
All models have multiple speed direct drive blower
motors. If supply and return ducts are connected to the
unit, the ducts must be of adequate size. Refer to the
appropriate blower tables. See Tables 10, 11, 12, 13,
14 and 15 for maximum static pressures acceptable.
Note the minimum CFM for cooling operation.
If voltage and duct design permit, (see blower tables)
single speed operation can be achieved as follows:
Blower Motor Speed Change
1. Disconnect power supply to unit.
2. Place desired blower motor speed lead wire to
“COOL” terminal of integrated furnace control
board.
3. Place desired blower motor speed lead wire to
“HEAT” terminal of integrated furnace control
board.
4. Place unused blower motor speed lead wire to
“UNUSED” terminal of integrated furnace control
board.
5. Energize the system in cooling and heating modes
to check for proper blower operation.
If it is desirable to have both HEAT/COOL blower motor
speed at the same speed, install a jumper wire between
“HEAT” and “COOL” terminals of the integrated
furnace control board, and place both unused motor
speed lead wires on the two “UNUSED” terminals on
the integrated furnace control board. (See Figure 20.)
Speeds 3-Speed Blower Motor
Low Red
Medium Blue
High Black
Speeds 3-Speed Blower Motor
Low Red
Medium Blue
High Black
Isolation * Orange
Isolation * Purple
FIGURE 20
FURNACE CONTROL BOARD AND BLOWER CONTROL
TABLE 9
230 VOLT MOTOR SPEED TAPS
460 VOLT MOTOR SPEED TAPS
* On 460 Volt motors, there are two motor isolation leads. The orange must connect with the black high
speed blower motor lead wire for medium and low speed blower operation. The purple wire must connect
with the blue medium speed blower motor lead wire for low speed blower operation. This is all automatically
accomplished with blower relays HSBR, MSBR and LSBR, and speed changes are all made by changes at the
integrated furnace control board.