Typical Control Wiring; Step 5 -- Unit Start-Up; Operating Manifold Gauge Set And Service Valves - Lennox Merit Series 13HPX Units Installation Instructions Manual

STEP 4 -- ELECTRICAL (CONTINUED) -- High Voltage and Field Control Wiring
The following illustration provide an example of control wiring connections when using standard thermostat.
HIGH VOLTAGE / GROUND WIRES
Any excess high voltage field wiring should be trimmed and secured away from any low voltage field wiring. To facilitate a conduit, a cutout is
located in the bottom of the control panel. Connect conduit to the control panel using a proper conduit fitting.

TYPICAL CONTROL WIRING

Install low voltage wiring from outdoor to indoor unit and from thermostat to indoor unit as illustrated.
A. Run 24VAC control wires through hole with grommet.
B. Make 24VAC thermostat wire connections to CMC1.
WIRE RUN LENGTH
LESS THAN 100' (30 METERS)
MORE THAN 100' (30 METERS) 16
HIGH VOLTAGE LOW VOLTAGE
FIELD WIRING FIELD WIRING
Low Voltage Wiring
Indoor Unit
Thermostat
R
POWER
C
COMMON
W1
1ST. STAGE AUX.
HEAT
G
INDOOR BLOWER
O
REVERSING VALVE
Y1
COMPRESSOR
(SOME CONNECTIONS MAY NOT APPLY. REFER
TO SPECIFIC THERMOSTAT AND INDOOR UNIT.)
NOTE — Wire tie provides low voltage wire strain relief and to maintain separation of field installed low and high voltage circuits.

STEP 5 -- UNIT START-UP

IMPORTANT
If unit is equipped with a crankcase heater, it should be
energized 24 hours before unit start-up to prevent
compressor damage as a result of slugging.
1. Rotate fan to check for binding.
2. Inspect all factory- and field-installed wiring for loose
connections.
3. After evacuation is complete, open the liquid line and
suction line service valve stems to release the
refrigerant charge (contained in outdoor unit) into the
system.
4. Replace the stem caps and tighten to the value listed in
table 3.
5. Check voltage supply at the disconnect switch. The
voltage must be within the range listed on the unit's
nameplate. If not, do not start the equipment until you
ROUTING HIGH VOLTAGE, GROUND AND CONTROL WIRING
AWG# INSULATION TYPE
18 TEMPERATURE RATING
35ºC MINIMUM.
FACTORY
WIRING
Outdoor Unit
R
POWER
C
COMMON
W1
1ST. STAGE AUX.
W2 HEAT
W3
G
NOTE — Do not bundle any excess 24VAC control wires inside control panel.
NOTE — For proper voltages, select thermostat wire (control wires) gauge
per table below.
Low Voltage Wiring (with Auxiliary Heat)
Thermostat
R
POWER
C
COMMON
E
EMERGENCY
HEAT
R
W1
C
1ST. STAGE AUX.
HEAT
W1
G
INDOOR BLOWER
O
Y1
O
(SOME CONNECTIONS MAY NOT APPLY. REFER TO
Y1
SPECIFIC THERMOSTAT AND INDOOR UNIT.)
FIGURE 13
have consulted with the power company and the voltage
condition has been corrected.
6. Connect manifold gauge set for testing and charging.
7. Set the thermostat for a cooling demand. Turn on power
to the indoor indoor unit and close the outdoor unit
disconnect switch to start the unit.
8. Recheck voltage while the unit is running. Power must
be within range shown on the unit nameplate.
9. Check system for sufficient refrigerate using the
procedures outlined in under System Refrigerant.
OPERATING MANIFOLD GAUGE SET AND SERVICE
VALVES
The liquid and vapor line service valves are used for
removing refrigerant, flushing, leak testing, evacuating,
checking charge and charging.
Each valve is equipped with a service port which has a
factory-installed valve stem. Figures 14 and 15 provides
information on how to access and operating both angle and
ball service valves.
Page 12
Indoor Unit Outdoor Unit
R
POWER
C
COMMON
EMER.
HEAT
RELAY
OUTDOOR
T'STAT
W1
1ST. STAGE AUX.
W2
HEAT
W3
G
REVERSING VALVE
COMPRESSOR
R
C
W1
O
Y1