24-V Wiring; Accessories; Venting; Removal Of Existing Furnaces From Common Vent Systems - Carrier 58MVP Installation, Start-Up, And Operating Instructions Manual

FIRE OR ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in intermittent unit
operation.
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.
CONTINUOUS FAN (CF) SETUP SWITCHES
The CF setup switches are used to select desired airflow when
thermostat is in continuous fan mode or to select low-cooling
airflow for two-speed cooling units. This setup feature allows
continuous fan airflow or low-cooling airflow to be adjusted. To
set desired continuous fan airflow or low-cooling airflow:
1. Remove main furnace door and blower access panel.
2. Locate CF setup switches on furnace control. (See Fig. 25.)
3. Determine desired continuous fan airflow or low-cooling
airflow.
4. Use Fig. 43 or wiring schematic to determine proper setup
position of CF switches. (See Fig. 24 and 44.)
5. Replace main furnace door and blower access panel.
SETUP SWITCHES (SW1)
The furnace control has 8 setup switches that may be set to meet
the application requirements. Position these setup switches for the
appropriate requirement.
1. Remove main furnace door and blower access panel.
2. Locate setup switches on furnace control. (See Fig. 25.)
3. See Table 8 for setup switch description. (See Fig. 24 and 44.)
4. Replace main furnace door and blower access panel.
NOTE: If a bypass humidifier is used, setup switch SW1-3 (Low
HEAT Rise Adjust) should be in ON position. This compensates
for the increased temperature in return air resulting from bypass.
NOTE: If modulating dampers are used, blower motor automati-
cally compensates for modulating dampers. 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.

24-V WIRING

Make field 24-v thermostat connections at 24-v terminal block on
furnace control. Y wire from thermostat MUST be connected to
Y/Y2 terminal on control, as shown in Fig. 21, for proper cooling
operation. The 24-v terminal block is marked for easy connection
of field wiring. (See Fig. 25.) The 24-v circuit contains a 3-amp,
automotive-type fuse located on furnace control. (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) and type. The
furnace control will flash status code 24 when fuse needs replace-
ment.
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.
NOTE: For additional thermostat connection diagrams, reference
Fig. 39-46.

ACCESSORIES

1. Electronic Air Cleaner (EAC)
The furnace control EAC terminals are energized with 115v
(1.0-amp maximum) during blower operation.
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. 25.)
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
C -24V screw terminal on the control board thermostat strip.
OM
The HUM terminal is energized when blower is energized in
heating. (See Fig. 25.)
UNIT DAMAGE HAZARD
Failure to follow this caution may result in unit component
damage.
DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat™, Zone Controller or
similar device. See Thermidistat™, Zone Controller, thermo-
stat, or controller manufacturer's instructions for proper
connection.
Step 7—Venting
The 58MVP furnaces require a dedicated (one 58MVP furnace
only) sealed vent system. All air for combustion is taken from the
area adjacent to the furnace, and all flue gases are discharged to
outdoor atmosphere.
REMOVAL OF EXISTING FURNACES FROM
COMMON VENT SYSTEMS
When an existing Category I furnace is removed or replaced, the
original venting system may no longer be sized to properly vent
the remaining 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, etc.
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