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PG80MSU: Installation, Start-up, Operating and Service and Maintenance Instructions
Electrical Connection to J-Box
Electrical Box on Furnace Casing Side
WARNING
!
FIRE OR ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury, death, or
property damage.
High voltage field connections must be located in J-Box with furnace,
or in field supplied external disconnect mounted to furnace.
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.
1. Select and remove a hole knockout in the casing where the
electrical box is to be installed.
NOTE: Check that duct on side of furnace will not interfere with
installed electrical box.
2. Remove the desired electrical box hole knockout and position the
hole in the electrical box over the hole in the furnace casing.
3. Fasten the electrical box to casing by driving two field supplied
screws from inside electrical box into casing steel.
4. Remove and save two screws holding J-Box.
5. Pull furnace power wires out of 1/2-in. (12 mm) diameter hole in
J-Box. Do not loosen wires from strain-relief wire-tie on outside of
J-Box.
6. Route furnace power wires through holes in casing and electrical
box and into electrical box, see
7. Pull field power wires into electrical box.
8. Remove cover from furnace J-Box.
9. Route field ground wire through holes in electrical box and casing,
and into furnace J-Box.
10. Reattach furnace J-Box to furnace casing with screws removed in
Step 4.
11. Secure field ground wire to J-Box green ground screw.
12. Complete electrical box wiring and installation. Connect line
voltage leads as shown in
for wire bushings, strain relief, etc.)
13. Reinstall cover to J-Box. Do not pinch wires between cover and
bracket.
Power Cord Installation in Furnace J-Box
NOTE: Power cords must be able to handle the electrical requirements
listed in
Table
6. Refer to power cord manufacturer's listings.
1. Remove cover from J-Box.
2. Route listed power cord through 7/8-in. (22 mm) diameter hole in
J-Box.
3. Secure power cord to J-Box bracket with a strain relief bushing or a
connector approved for the type of cord used.
4. Secure field ground wire to green ground screw on J-Box bracket.
5. Connect line voltage leads as shown in
6. Reinstall cover to J-Box. Do not pinch wires between cover and
bracket.
BX Cable Installation in Furnace J-Box
1. Remove cover from J-Box.
2. Route BX cable into 7/8-inch diameter hole in J-Box.
3. Secure BX cable to J-Box bracket with connectors approved for the
type of cable used.
4. Secure field ground wire to green ground screw on J-Box bracket.
5. Connect line voltage leads as shown in
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
Fig.
25.
Fig.
23. Use best practices (NEC in U.S.
Fig.
23.
Fig.
23.
6. Reinstall cover to J-Box. Do not pinch wires between cover and
bracket.
Fig. 25 – Field-Supplied Electrical Box on Furnace Casing
24-V Wiring
Make field 24-V connections at the 24-V terminal strip, see
Connect terminal Y as shown in
Use only AWG No. 18, color-coded, copper thermostat 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.
ACCESSORIES
1. Electronic Air Cleaner (EAC)
Connect an accessory Electronic Air Cleaner (if used) using 1/4-in
female quick connect terminals to the two male 1/4-in
quick-connect terminals on the control board marked EAC and
NEUTRAL. The terminals are rated for 115 VAC, 1.0 amps
maximum and are energized during blower motor operation, see
Fig.
26.
2. Humidifier (HUM)
Connect an accessory 24 VAC, 0.5 amp. maximum humidifier (if
used) to the 1/4-in male quick-connect HUM terminal and
COM-24V screw terminal on the control board thermostat strip.
The HUM terminal is energized when the pressure switch closes
during a call for heat, see
NOTE: DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on humidity sensing thermostat, zone controller or
similar device. See humidity sensing thermostat, zone controller,
thermostat, or controller manufacturer's instructions for proper
connection. For 24-V & 115-V EAC or Humidifier Accessory details,
see Accessory instructions.
15
Fig. 36
for proper cooling operation.
Fig.
26.
A10141
Fig.
23.
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