Power Cord Installation In Furnace J-Box; Bx Cable Installation In Furnace J-Box; 24-V Wiring; Accessories - Carrier 58CTA Installation And Service Instructions Manual

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. (See Fig. 23.)
5. Pull furnace power wires out of 1/2-inch 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.
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 re-
moved 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 Fig. 22. Use best practices (NEC in
U.S. and CSA C22.1 in Canada) 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 require-
ments listed in Table 7. Refer to power cord manufacturer's
listings.
→
1. Remove cover from J-Box.
2. Route listed power cord through 7/8-inch 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 Fig. 22.
→
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 Fig. 22.
→
6. Reinstall cover to J-Box. Do not pinch wires between cover
and bracket.

24-V WIRING

Make field 24-v connections at the 24-v terminal strip. (See Fig.
32.) Connect terminal Y/Y2 as shown in Fig. 25-31 for proper
cooling operation. 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-1
and EAC-2. The terminals are rated for 115VAC, 1.0 amps
maximum and are energized during blower motor operation.
(See Fig. 32.)
2. Humidifier (HUM)
Connect an accessory 24 VAC, 0.5 amp maximum humidifer
(if used) to the 1/4-in male quick-connect HUM terminal and
C -24V screw terminal on the control board thermostat strip.
OM
The HUM terminal is energized when gas valve relay (GVR)
is energized. (See Fig. 32.)
NOTE: A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during blower operation.
NOTE: DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat, Zone Controller or similiar
device. See Thermidistat™, Zone Controller, thermostat, or con-
troller manufacturer's instructions for proper connection.

VENTING

The furnace shall be connected to a listed factory built chimney or
vent or a clay-tile lined masonry or concrete chimney. Venting into
an unlined masonry chimney or concrete chimney is prohibited.
When an existing Category I furnace is removed or replaced, the
original venting system may no longer be sized to properly vent
the attached appliances. An improperly sized Category I venting
system could cause the formation of condensate in the furnace and
vent, leakage of condensate and combustion products, and spillage
of combustion products into the living space.
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