Lennox MERIT Series Installation Instructions Manual page 36

Install a separate (properly sized) disconnect switch near
the furnace so that power can be turned off for servicing.
Before connecting the thermostat or the power wiring,
check to make sure the wires will be long enough for ser-
vicing at a later date. Remove the blower access panel to
check the length of the wire.
Complete the wiring connections to the equipment. Use
the provided unit wiring diagram and the field wiring dia-
gram shown in Figure 53. 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) for the USA
and current Canadian Electric Code part 1 (CSA standard
C22.1) for Canada. A green ground wire is provided in the
field make-up box.
NOTE - The ML196DFE furnace contains electronic com-
ponents that are polarity sensitive. Make sure that the fur-
nace is wired correctly and is properly grounded.
Accessory Terminals
One line voltage "EAC" 1/4" spade terminal is provided on
the furnace integrated control. See Figure 54 for integrat-
ed 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 "120 HUM" 1/4" spade terminal is pro-
vided on the furnace integrated control. See Figure 54 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 con-
nected 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 fur-
nace integrated control. See Figure 54 for integrated con-
trol 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.
Install the room thermostat according to the instructions
provided with the thermostat. See Figure 53 for thermo-
stat designations. If the furnace is being matched with a
heat pump, refer to thermostat installation instructions for
set up.
Indoor Blower Speeds
1 - When the thermostat is set to "FAN ON," the indoor
blower will run continuously on the fan speed (FAN)
when there is no cooling or heating demand. See
TABLE 20 on page 50 for allowable circulation
speeds.
2 - When the ML196DFE is running in the heating mode,
the indoor blower will run on the heating speed
(HEAT). See TABLE 19 on page 50 for allowable
heating speeds.
3 - When there is a cooling demand, the indoor blower
will run on the cooling speed (COOL).
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 po-
larity and proper ground. Both polarity and proper
grounding should be checked before attempting to
operate the furnace on either permanent or tempo-
rary power
• Generator should have a wave form distortion of
less than 5% THD (total harmonic distortion)
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