J−Box Installation - International comfort products R9MSB0801716 Installation Instructions Manual

INSTALLATION INSTRUCTIONS
J−Box Installation
WARNING
!
FIRE OR ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, death, or property damage.
If field−supplied manual disconnect switch is to be
mounted on furnace casing side, select a location
where a drill or fastener cannot damage electrical or
gas components.
The J−Box is used when field line voltage electrical
connections are made to the furnace wiring harness inside the
furnace casing. The J−Box cover is not required if an external
electrical box is attached to the outside of the furnace casing.
The field wiring and main wiring harness are grounded with the
furnace box is grounded to the green ground screw of the
J−Box bracket and the earth ground of the field electrical
supply.
The J−Box cover, mounting bracket and screws are shipped in
the loose parts bag included with the furnace. See Figure 36
for J−Box mounting locations.
The J−Box mounting bracket and green ground screw is used
as a grounding point for all line voltage wiring options. The
J−Box cover may be omitted when electrical connections are
made inside an external electrical box mounted external to the
casing.
External Electrical Box on Furnace Casing
Note: Check to ensure that external electrical box does not
interfere with ductwork, gas piping or the indoor coil drain. See
Figure 35 for alternate electric entry through top panel.
1. Select and remove 7/8−in. (22 mm) knock−out on the
desired side of the casing. Remove the knock−out from
the casing.
NOTE: If electrical entry through the furnace top panel is used,
a 7/8−in. (22 mm) hole must be drilled through the top panel.
2. Drill two (2) 1/8−in. (3 mm) pilot holes through the
dimples in the furnace casing near the 7/8−in. knock−out.
NOTE: If electrical entry through the furnace top panel is used,
mark the screw hole locations using the mounting holes in the
external electrical box as a template.
For a side−mounted external electrical box, complete the
following:
3. Align the J−Box bracket with the knock−out inside the
furnace casing.
4. Install the threaded end of a strain−relief bushing through
the J−Box bracket and the furnace casing. Strain−relief
bushing should be installed so that the bushing can be
tightened around the wiring harness inside the furnace
casing.
5. Align the field−supplied external electrical box with the
7/8−in. (22 mm) knock−out.
6. Install and tighten the lock−nut on the strain−relief
bushing inside the external electrical box.
7. Fasten the external electrical box to the furnace casing
using two (2) sheet metal screws.
8. Route field power wiring into external electrical box.
9. Pull furnace line voltage power wires through strain−relief
bushing of the external electrical box.
10. Pull the ground wire of the field line voltage wiring
through the strain−relief bushing into the furnace casing.
440 01 6001 05
11. Install the green ground screw to the J−Box bracket and
attach both ground wires to the green ground screw.
12. Connect any code required external disconnect(s) to field
power wiring.
13. Connect field power and neutral leads to furnace power
leads inside the external electrical box as shown in
Figure 36.
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 two (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 as shown in
Figure 37.
Power Cord Installation in Furnace J−Box
NOTE:
requirements listed in Table 10. Refer to power cord
manufacturer's listings.
1. Install J−Box mounting bracket to inside of furnace
casing. (See Figure 36.)
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 as
shown in Figure 36.
6. Connect power cord power and neutral leads to furnace
power leads as shown in Figure 39.
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 Figure 36).
BX Cable Installation in Furnace J−Box
1. Install J−Box mounting bracket to inside of furnace
casing. See Figure 36.
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 as
shown in Figure 36.
5. Connect field power and neutral leads to furnace power
leads. as shown in Figure 39.
6. Attach furnace J−Box cover to mounting bracket with
screws supplied in loose parts bag. Do not pinch wires
between cover and bracket.
Specifications subject to change without notice.
Gas Furnace: R9MSB
Power cords must be able to handle the electrical
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