Lennox International Inc G50UH-48C-110 PowER @1HsuN,T, Interiormake-Upbox Installation

INTERIORMAKE-UP BOX INSTALLATION

MAKE-UP

Left side / BOX

_ °

FIGURE 22

Refer to figure 24 for field wiring and figure 26 for schematic wiring diagram and troubleshooting.

1 - Select circuit protection and wire size according to the unit nameplate. The power supply wiring must meet Class I restrictions,

2 - Holes are on both sides of the furnace cabinet to facili- tate wiring,

3 - Install a separate disconnect switch (protected by ei- ther fuse or circuit breaker) near the furnace so that power can be turned off for servicing,

4 - Before connecting the thermostat or the power wiring, check to make sure the wires will be long enough for servicing at a later date, Remove the blower access panel to check the length of the wire,

5- Complete the wiring connections to the equipment. Use the provided unit wiring diagram and the field wir- ing diagram shown in figure 24, Use 18-gauge wire or larger that is suitable for Class II rating for thermostat connections,

6 - 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 G5OUH(X) furnace contains electronic components that are polarity sensitive. Make sure that the furnace is wired correctly and is properly grounded.

7 - One line voltage "EAC" terminal is provided on the fur- nace control board. Any electronic air cleaner rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to any of the "NEUTRAL" terminals. See figure 25 for control board configuration. This terminal is energized when the blower is operating,

8 - One line voltage "HUM" terminal is provided on the fur- nace control board, A humidifier rated up to one amp can be connected to this terminal with the neutral leg of the circuit being connected to any of the "NEUTRAL" terminals. See figure 25 for control board configura- tion. This terminal is energized in the heating mode whenever the combustion air inducer is operating.

9 - One 24 volt terminal "24V HUM" is provided on the fur- nace control board. A humidifier rated up to 0.5 amp can be connected to this terminal with the common leg

of the circuit being connected to the "C" terminal d the thermostat terminal block located on the control board.

10-Install the room thermostat according to the instruc- tions provided with the thermostat. See figure 23 for thermostat designations. If the furnace is being

matched with a heat pump, refer to the FM21 installa- tion instruction.

G50UH(X) and CONDENSING UNIT

THERMOSTAT DESIGNATIONS

(Refer to specific thermostat and outdoor unit.)

ThermostatG50UH(X)Condensing

FurnaceUnit

PowER

@1HsuN,T

FIGURE 23

Indoor Blower Speeds

1 - When the thermostat is set to "FAN ON," the indoor blower will run continuously on the low speed when there is no cooling or heating demand,

2 - When the G50UH(X)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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