935CA: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
26
A11146
Fig. 39 – Field-Supplied External Electrical Box on Furnace Casing
6. Route field power wiring into external electrical box.
7. Pull furnace line voltage power wires through strain-relief bushing
of the external electrical box.
8. Pull the ground wire of the field line voltage wiring through the
strain-relief bushing into the furnace casing.
9. Install the green ground screw to the J-Box bracket and attach both
ground wires to the green ground screw.
10. Connect any code required external disconnect(s) to field power
wiring.
11. Connect field power and neutral leads to furnace power leads inside
the external electrical box, see
Fig. 32
.
For a top panel-mounted external electrical box,
complete the following:
1. Drill two (2) 1/8-in. (3 mm) pilot holes through the dimples in the
furnace casing near the 7/8-in. knock-out on the side of the casing.
Do not remove the knock-out in the side of the casing.
2. Align the J-Box bracket with the pilot holes inside the furnace
casing.
3. Install 2 screws through the outside of the casing to secure the
J-Box bracket to the furnace casing.
4. Route field power wiring into external electrical box.
5. Pull furnace line voltage power wires through strain-relief bushing
of the external electrical box.
6. Pull the ground wire of the field line voltage wiring through the
strain-relief bushing into the furnace casing.
7. Install the green ground screw to the J-Box bracket and attach both
ground wires to the green ground screw.
8. Connect any code required external disconnect(s) to field power
wiring.
9. Connect field power and neutral leads to furnace power leads inside
the external electrical box, see
Fig. 34
.
Power Cord Installation in Furnace J-Box
NOTE:
Power cords must be able to handle the electrical requirements,
see
Table 13
. Refer to power cord manufacturer’s listings.
1. Install J-Box mounting bracket to inside of furnace casing, see
Fig. 38
.
2. Route listed power cord through 7/8-in. (22 mm) diameter hole in
casing and J-Box bracket.
3. Secure power cord to J-Box bracket with a strain relief bushing or a
connector approved for the type of cord used.
4. Pull furnace power wires through 1/2-in. (12 mm) diameter hole in
J-Box. If necessary, loosen power wires from strain—relief wire-tie
on furnace wiring harness.
5. Connect field ground wire and factory ground wire to green ground
screw on J-Box mounting bracket, see
Fig. 38
.
6. Connect power cord power and neutral leads to furnace power
leads, see
Fig. 40
.
7. Attach furnace J-Box cover to mounting bracket with screws
supplied in loose parts bag. Do not pinch wires between cover and
bracket, see
Fig. 38
.
BX Cable Installation in Furnace J-Box
1. Install J-Box mounting bracket to inside of furnace casing, see
Fig. 38
.
2. Route BX connector through 7/8-in. (22 mm) diameter hole in
casing and J-Box bracket.
3. Secure BX cable to J-Box bracket with connectors approved for the
type of cable used.
4. Connect field ground wire and factory ground wire to green ground
screw on J-Box mounting bracket, see
Fig. 38
.
5. Connect field power and neutral leads to furnace power leads, see
Fig. 40
.
6. Attach furnace J-Box cover to mounting bracket with screws
supplied in loose parts bag. Do not pinch wires between cover and
bracket.
24-V Wiring
Make field 24-v connections at the 24-v terminal strip, see
Fig. 42
.
Connect terminal Y/Y2, see
Fig. 76
, for proper cooling operation. Use
only AWG No. 18, color-coded, copper thermostat wire.
NOTE:
Use AWG No. 18 color-coded copper thermostat wire for
lengths up to 100 ft. (31 M). For wire lengths over 100 ft., use AWG No.
16 wire.
The 24-v circuit contains an automotive-type, 3-amp. fuse located on the
control. Any direct shorts during installation, service, or maintenance
could cause this fuse to blow. If fuse replacement is required, use ONLY
a 3-amp. fuse of identical size, see
Fig. 42
.
Thermostats
A single stage heating and cooling thermostat can be used with the
furnace. The furnace control board CPU will control the outdoor unit
staging. A 2-stage thermostat can also be used to control the two-stage
cooling. For 2-stage thermostat control of a 2-stage outdoor unit, remove
the ACRDJ jumper from the furnace control board. Refer to typical
thermostat wiring diagrams and the Sequence of Operation section for
additional details. Consult the thermostat installation instructions for
specific information about configuring the thermostat., see
Fig. 42
and
Thermostat wiring)
COPPER
WIRE ONLY
ELECTRIC
DISCONNECT
SWITCH
ALUMINUM
WIRE
GROUND
NEUTRAL
LINE VOLTAGE
WARNING
!
FIRE, EXPLOSION, ELECTRICAL SHOCK, AND
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in dangerous operation,
personal injury, death, or property damage.
Do not drill into blower shelf of furnace to route control wiring. Route
any control or accessory wiring to the blower compartment through
external knockouts on the casing.