TM 9-4120-388-14
4-11. INSTALLATION INSTRUCTIONS - Continued.
d. Seal all openings around cutouts for air conditioner, air and watertight. Use gasket, caulking, or other suitable
material.
The air conditioner is provided with four drain holes in base. (See Figure 4-2.) Remove plugs from ail drains
e.
possible for most complete drainage of condensate water. If water from these drains will be objectionable or
create a hazard, external overboard drains can be connected. Use standard 1/2-14NPT male pipe fittings to
connect base drains. Any type of hose or tubing maybe used as a drain line. The drain line should lead to an
appropriate facility drain, storm sewer, dry sump, or an acceptable outside area. Be sure the entire length of
the drain line is at the same height, or lower than the base to ensure gravity drainage.
f.
Install a 10 AWG minimum ground wire between air conditioner cabinet and an adequate earth ground. Suggested
locations are any unused threaded fasteners on rear panel.
g. Fabricate a power cable. (See para 4-12.)
The following test must be conducted with the power on. Exercise extra caution.
Do not connect (P1) connector to air conditioner before making following checks.
h.
Connect power cable to 208 volt, 3 phase, 50/60 hertz power source. (See para 4-12 and Figure 4-18.)
(1)
Apply power to power cable.
(2)
Use a multimeter set to AC voltage range of at least 250 volts for following tests.
Measure voltage between pin D of connector (P1) and a good chassis ground. Voltage must be zero (0). If more
(3)
than zero voltage is observed, disconnect cable and check power source. Correct problem at power source.
With zero voltage on pin D of (P1) connector, check voltages between remaining pins as shown on following chart.
(4)
P1 CONNECTOR
To Pin
Measure
A
from Pin
B
C
D
120
A
N/A
208
208
120
208
N/A
208
B
120
208
208
N/A
C
120
D
120
120
N/A
Voltages should be approximately as shown. if voltages are not within ten volts of those indicated on chart, disconnect
power. Locate and correct problem.
Be sure that mode selector switch is OFF.
(5) After proper voltages are indicated on all pins of connector (P1), connect (P1) to connector (J1) on air conditioner.
NOTE
The following steps require two people. One must be at control panel. The other must
be in position at rear of air conditioner to see condenser fan rotation. (Condenser fan can
be seen through condenser air outlet grille, Figure 1-2, item 16.)
(6) The person at control panel should turn mode selector switch to VENT and immediately back to OFF.
(7) The person at rear of unit should watch condenser fan to determine direction of rotation. Fan blades must turn
toward grille.
4-16
