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Table 3. Wire Run Lengths
Wire run length
AWG #
Insulation type
Less than 100 feet (30 m)
18
Color−coded with a minimum
temperature rating of 35
º
C.
More than 100 feet (30 m)
16
2. Ground unit at unit disconnect switch or to an earth
ground.
NOTE − For proper voltages, select thermostat wire gauge
per the following table:
3. Connect conduit to the unit using provided conduit
bushing.
4. Install room thermostat (ordered separately) on an
inside wall approximately in the center of the
conditioned area and five feet (1.5 m) from the floor.
It should not be installed on an outside wall or where
it can be affected by sunlight, drafts or vibrations.
5. Install low voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit as illustrated in
figures 15 and 16.
6. Do not bundle any excess 24V control wire inside
control box. Run control wire through installed wire tie
and tighten wire tie to provided low voltage strain relief
and to maintain separation of field installed low and
high voltage circuits.
THREE-PHASE SCROLL VOLTAGE PHASING
Three-phase scroll compressors must be phased
sequentially to ensure correct compressor rotation and
operation. Incorrect line voltage phasing may cause
compressor damage and abnormal unit operation. Power
wires are color-coded as follows: Line 1 − red, line 2 − yellow,
line 3 − blue.
To test for proper rotation and operation:
1. Install manifold gauge set on system. Cycle compressor
ON
and observe that suction pressure decreases and
discharge pressure increases.
2. If pressures do not follow the above conditions,
disconnect all power to unit. Reverse any two
field−installed main power wires to the line side of the
compressor contactor. Make sure connections are tight.
Repeat pressure test with system.
Servicing Units Delivered Void of Charge
If the outdoor unit is void of refrigerant, clean the system
using the procedure described below.
1. Leak check system using procedure outlined in this
instruction.
2. Evacuate the system using procedure outlined in this
instruction.
3. Use nitrogen to break the vacuum and install a new
filter drier in the system.
4. Evacuate the system again using procedure outlined
in this instruction.
5. Weigh in refrigerant using procedure in figure 21.
Start−Up
IMPORTANT
Crankcase heater (if applicable) should be energized 24
hours before unit start−up to prevent compressor dam-
age as a result of slugging.
1. Check that fan rotates freely.
2. Inspect all factory− and field−installed wiring for loose
connections.
3. After evacuation is complete, open both the liquid and
vapor line service valves to release the refrigerant
charge contained in outdoor unit into the system.
4. Replace the stem caps and tighten as specified in
Operating Service Valves
on page 4.
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
have consulted with the power company and the
voltage condition has been corrected.
6. 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.
7. Recheck voltage while the unit is running. Power must
be within range shown on the nameplate.
8. Check system for sufficient refrigerate by using the
procedures listed under
System Refrigerant
.
System Refrigerant
This section outlines procedures for:
1. Connecting gauge set for testing and charging;
2. Checking and adjusting indoor airflow;
3. Adding or removing refrigerant.
