507651-01
Issue 1907
Page 21 of 32
Figure 20. Interior Make-Up Box Installation
Failure to use properly sized wiring and circuit breaker
may result in property damage. Size wiring and circuit
breaker(s) per unit rating plate.
CAUTION
NOTE:
Unit nameplate states maximum current draw.
Maximum over current protection allowed is 15 AMP.
Holes are on both sides of the furnace cabinet to facilitate
wiring.
Install a separate (properly sized) disconnect switch near
the furnace so that power can be turned off for servicing.
Before connecting the thermostat, check to make sure the
wires will be long enough for servicing at a later date. Make
sure that thermostat wire is long enough to facilitate future
removal of blower for service.
Complete the wiring connections to the equipment. Use the
provided unit wiring diagram and the wiring diagram shown
in Figure 22 or Figure 23. Use 18 gauge wire or larger that
is suitable for Class II rating for thermostat connections.
Electrically ground the unit according to local codes or,
in the absence of local codes, according to the current
National Electric Code (ANSI/NFPA No. 70). A green
ground wire is provided in the field make-up box.
NOTE:
This furnace contains electronic components that
are polarity sensitive. Make sure that the furnace is wired
correctly and is properly grounded.
Electric Shock Hazard. Can cause injury
or death. Unit must be properly grounded
in accordance with national and local
codes.
WARNING
Accessory Terminals
One line voltage “EAC” 1/4” spade terminal is provided on
the furnace integrated control. See Figure 24 for integrated
control configuration. This terminal is energized when the
indoor blower is operating. Any accessory rated up to one
amp can be connected to this terminal with the neutral
leg of the circuit being connected to one of the provided
neutral terminals. If an accessory rated at greater than one
amp is connected to this terminal, it is necessary to use an
external relay.
One line voltage “HUM” 1/4” spade terminal is provided
on the furnace integrated control. See Figure 24 for
integrated control configuration. This terminal is energized
in the heating mode when the combustion air inducer is
operating. Any humidifier rated up to one amp can be
connected to this terminal with the neutral leg of the circuit
being connected to one of the provided neutral terminals. If
a humidifier rated at greater than one amp is connected to
this terminal, it is necessary to use an external relay.
One 24V ”H” 1/4” spade terminal is provided on the furnace
integrated control. See Figure 24 for integrated control
configuration. The terminal is energized in the heating
mode when the combustion air inducer is operating and
the pressure switch is closed. Any humidifier rated up to
0.5 amp can be connected to this terminal with the ground
leg of the circuit connected to ground or the ”C” terminal.
Generator Use - Voltage Requirements
The following requirements must be kept in mind when
specifying a generator for use with this equipment:
•
The furnace requires 120 volts ± 10% (Range: 108
volts to 132 volts).
•
The furnace operates at 60 Hz ± 5% (Range: 57 Hz
to 63 Hz).
•
The furnace integrated control requires both polarity
and proper ground. Both polarity and proper grounding
should be checked before attempting to operate the
furnace on either permanent or temporary power.
•
Generator should have a wave form distortion of less
than 5% RHO.
Thermostat
Install the room thermostat according to the instructions
provided with the thermostat. See Figure 22 or Figure 23
for thermostat designations. If the furnace is being matched
with a heat pump, refer to the FM21 installation instruction
or appropriate dual fuel thermostat instructions.
Indoor Blower Speeds
1. When the thermostat is set to “FAN ON,” the indoor
blower will run continuously on the fan speed when
there is no cooling or heating demand.
2. When the unit is running in the heating mode, the
indoor blower will run on the heating speed.
3. When there is a cooling demand, the indoor blower will
run on the cooling speed.
