24-V Wiring; Accessories - Carrier 58MVP Installation, Start-Up, And Operating Instructions Manual

rating plate. Also, check to be sure that service provided by utility
is sufficient to handle load imposed by this equipment. Refer to
rating plate or Table 3 for equipment electrical specifications.
Make all electrical connections in accordance with NEC
ANSI/NFPA 70-1993 and any local codes or ordinances that might
apply. For Canadian installations, all electrical connections must
be made in accordance with Canadian Electrical Code CSA C22.1
or subauthorities having jurisdiction.
ELECTRIC
DISCONNECT
SWITCH
Do not connect aluminum wire between disconnect switch
and furnace. Use only copper wire.
Use a separate, fused branch electrical circuit containing a properly
sized fuse or circuit breaker for this furnace. See Table 3 for wire
size and fuse specifications. A disconnecting means must be
located within sight from and readily accessible to furnace.
NOTE: Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, control center fault code indicator light will
flash rapidly and furnace will NOT operate.
The cabinet MUST have an uninterrupted or unbroken ground
according to NEC ANSI/NFPA 70-1993 and Canadian Elec-
trical Code CSA C22.1 or local codes to minimize personal
injury if an electrical fault should occur. This may consist of
electrical wire or conduit approved for electrical ground when
installed in accordance with existing electrical codes. Do not
use gas piping as an electrical ground. Failure to follow this
warning could result in electric shock, fire, or death.
Fig. 24—Relocating J-Box
J-Box Relocation
1. Remove 2 screws holding auxiliary J-box. (See Fig. 24.)
COPPER
WIRE ONLY
ALUMINUM
WIRE
A93033
A93051
2. Rotate J-box 180° and attach box to right side, using holes
provided.
If manual disconnect switch is to be mounted on furnace,
select a location where a drill or fastener will not contact
electrical or gas components.
Step 2—24-v Wiring
Make field 24-v thermostat connections at 24-v terminal block on
control center. Y wire from thermostat MUST be connected to Y
terminal on control center, as shown in Fig. 22, for proper cooling
operation. The 24-v terminal board is marked for easy connection
of field wiring. (See Fig. 23.) The 24-v circuit contains a 3-amp,
automotive-type fuse located on control center. (See Fig. 25.) Any
electrical shorts of 24-v wiring during installation, service, or
maintenance may cause fuse to blow. If fuse replacement is
required, use only a fuse of identical size (3 amp).
NOTE: Use AWG No. 18 color-coded copper thermostat wire for
lengths up to 100 ft. For wire lengths over 100 ft, use AWG No.
16 wire.
Step 3—Accessories
1. Electronic Air Cleaner (EAC)
The control center EAC terminals are energized with 115v
(1.5-amp maximum) during blower operation.
a. Two extension leads are connected to the control center
EAC terminals to assist field installation of an EAC. (See
Fig. 25.) To use these leads, proceed with the following:
(1.) Strip EAC power lead insulation approximately 1/4-in.
(2.) Insert stripped end into factory-supplied black lead's
butt connector and crimp to secure.
(3.) Strip EAC neutral lead insulation approximately 1/4-
in.
(4.) Insert stripped end into factory-supplied white leads's
butt connector and crimp to secure.
NOTE: If desired, cut butt connectors off factory leads and strip
insulation approximately 1/4-in and use field supplied wire nuts to
connect.
b. An alternate method to attach EAC lead to control center is
the following procedure:
(1.) Remove 2 screws securing the control box to furnace
blower shelf.
(2.) Remove and discard 2 factory-supplied leads from
control center EAC terminals.
(3.) Strip EAC power leads insulation approximately 1/8-
in.
NOTE: The control center EAC terminals are sized for 12 gage
maximum, solid or stranded wire.
(4.) Route EAC leads through right-hand wire grommet.
(5.) Insert EAC stripped leads into control center EAC
terminals by depressing terminal's arm with a screw-
driver or finger. (See Fig. 26.)
(6.) Reinstall control box to furnace blower shelf using 2
screws removed earlier.
2. Humidifier (HUM)
Screw terminals (HUM and Com) are provided for 24-v
humidifier connection. (See Fig. 23.) HUM terminal is ener-
gized with 24v (0.5-amp maximum) after inducer motor
prepurge period.
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