12
443 06 2403 01
Specifications subject to change without notice.
Figure 12
−
TKR Relay Secured with Factory
−
Supplied Screws
2. Install Auxiliary Limit Switch (ALS
−
M) on L/H furnace:
a. Drill 1/8
−
in. hole in blower housing 12 in. (305
mm)below blower shelf. (See Figure 13)
b. Position ALS
−
M so reset button faces front of
furnace.
c. Secure bracket to blower housing using a
factory
−
supplied screw.
d. Disconnect red transformer wire from LH furnace
control 24 VAC connection.
e. Connect red transformer wire connector to ALS
−
M
wire connector PLC labeled TRAN.
f. Connect orange ALS
−
M wire connector labeled SEC
1 to LH furnace control 24 VAC terminal.
g. If Extension Harness was used, connect 2
−
wire
harness to Extension Harness
3. Install Secondary 4
−
wire harness on R/H furnace:
The Secondary Harness includes the Auxiliary Door Switch
and Auxiliary Limit Switch. The harness is also tagged
“Secondary Furnace” near the plug ends of the harness.
a. Connect red wire labeled R
−
Secondary to RH
furnace control thermostat connection R.
b. Connect white wire labeled W
−
Secondary to RH
furnace control thermostat connection W.
c. Connect black wire labeled C
−
Secondary to RH
furnace control thermostat connection C.
d. Connect yellow wire labeled TEST SECONDARY to
RH furnace control TEST/TWIN terminal.
e. If the furnaces are side
−
by
−
side, route loose ends of
4
−
wire harness from Secondary furnace to Main
furnace through snap bushings previously installed
between furnaces. (See Figure 4)
f. Connect Secondary 4
−
wire harness into 4
−
wire Main
harness.
g. If Extension Harness was installed, connect 4
−
wire
Secondary Harness to the Extension Harness.
4. Install Auxiliary Limit Switch, ALS
−
S on Secondary
furnace:
a. Drill 1/8
−
in. hole in blower housing 12 in. (305
mm)below blower shelf. (See Figure 13)
b. Position ALS
−
S with terminals facing front of furnace.
c. Secure bracket to blower housing using
factory
−
supplied screw.
5. Install Auxiliary Blower Door Interlock Switch, (See
Figure 13) ILK
−
1 on Secondary furnace:
NOTE
: This kit contains two auxiliary blower door switch
brackets. Assure that switch bracket used matches bracket
used for factory installed blower door switch.
a. Measure along the left edge of the furnace casing, 6
inches (152 mm) down from blower shelf.
b. Drill a 3/16
−
in. clearance hole through front edge of
blower door support.
c. Insert blower door switch mounting tab behind front
edge of blower door support.
d. Secure auxiliary door switch ILK
−
1 using
factory
−
supplied screw.
e. Connect 2
−
Wire Secondary Harness to 2
−
wire Main
Harness that was routed through furnace casings.
f. If extension harness was installed, 2
−
wire Secondary
Harness from Secondary to Main Extension Harness.
NOTE
: If Extension Harness will not plug in to L/H and R/H
furnaces, extension harness is installed backward. Remove
extension harness and re
−
install in correct orientation.
6. Select identical blower motor speed taps at control
center connectors in both furnaces.
UNIT DAMAGE HAZARD
Failure to follow this caution may result equipment
damage.
Failure to select identical blower speed taps in both
furnaces can result in overheating of furnace
components and possible loss of furnace operation and
damage to the furnaces.
CAUTION
!
7. Dress wires to ensure they do not contact sharp or
moving parts nor interfere with blower operation,
removal of filters, or operation of switches.
8. Make all thermostat connections to LH furnace only. See
