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 field wiring diagram shown in figure 33. Use 18−gauge wire or larger that is suit- able 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 Na- tional Electric Code (ANSI/NFPA No. 70). A green ground wire is provided in the field make−up box.
NOTE − The ML180UH furnace contains electronic compo- nents that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.
Accessory Terminals
One line voltage ade terminal is provided on
the furnace integrated control. See figure 34 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
SThe furnace requires 120 volts + 10% (Range: 108 volts to 132 volts).
SThe furnace operates at 60 Hz + 5% (Range: 57 Hz to 63 Hz).
SThe 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.
SGenerator should have a wave form distortion of less than 5% RHD.
Thermostat
Install the room thermostat according to the instructions provided with the thermostat. See figure 31 for thermostat designations. If the furnace is being matched with a heat pump, refer to the FM21 installation instruction or appropri- ate dual fuel thermostat instructions.
ML180UH and CONDENSING UNIT
THERMOSTAT DESIGNATIONS
(Refer to specific thermostat and outdoor unit.)
Thermostat | Furnace | Condensing |
|
| Unit |
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 exter- nal relay.
One line voltage ade terminal is provided on
the furnace integrated control. See figure 34 for integrated control configuration. This terminal is energized in the
R
W1
Y
G
C
POWER
HEAT
COOLING
INDOOR BLOWER
COMMON
R
W
Y
G
C
*CONDENSING
UNIT
CONDENSING
UNIT
CONDENSING UNIT COMMON
heating mode when the combustion air inducer is operat- ing. Any humidifier rated up to one amp can be connected to this terminal with the neutral leg of the circuit being con- nected to one of the provided neutral terminals. If a humidi- fier rated at greater than one amp is connected to this termi- nal, it is necessary to use an external relay relay.
Generator Use − Voltage Requirements
The following requirements must be kept in mind when specifying a generator for use with this equipment:
*NOTE −
FIGURE 31
Indoor Blower Speeds
1 − When the thermostat is set to AN ON," the indoor blower will run continuously on the heating speed when there is no cooling or heating demand.
2 − When the ML180UH 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.
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