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Installation, Operation & Maintenance - HKV Series
LT1
LT2
LT1
LT1
LT2
LT2
f. Check air temperature drop across the coil when
compressor is operating. Air temperature should
drop between 15°F [8°C] and 25°F [14°C].
g. Turn thermostat to “OFF” position. A hissing noise
indicates proper functioning of the reversing valve.
6. Operate the heat pump in the heating cycle
immediately after checking cooling cycle operation.
Allow five (5) minutes between tests for pressure to
equalize or cycle the reversing valve to equalize.
a. Turn thermostat to lowest setting and set
thermostat switch to “HEAT” position.
b. Slowly turn thermostat to a higher temperature
until the compressor activates.
c. Check for warm air delivery at the unit grille within
a few minutes after the unit has begun to operate.
d. Check the temperature of both supply and
discharge water. Refer to Table 8. If temperature is
within range, proceed with test. If temperature is
outside operating range, check heating refrigerant
pressures in Table 8.
e. Check air temperature rise across the coil when
compressor is operating. Air temperature should
rise between 20°F [11°C] and 30°F [17°C]. Heat
of extraction can be calculated and compared to
specification catalog.
f. Check for vibration, noise, and water leaks.
7. If unit fails to operate, perform troubleshooting
analysis (CXM AOM or DXM2 AOM). If the check
described fails to reveal the problem and the unit
still does not operate, contact a trained service
technician to ensure proper diagnosis and repair of the
equipment.
8. When testing is complete, set system to maintain
desired comfort level.
9. BE CERTAIN TO FILL OUT AND FORWARD
ALL WARRANTY REGISTRATION PAPERS
TO Comfort-Aire/Century.
Note: If performance during any mode appears
abnormal, refer to the troubleshooting section of CXM
or DXM2 AOM. To obtain maximum performance
the air coil should be cleaned before start-up. A
10% solution of dishwasher detergent and water is
recommended.
1. Turn thermostat fan position to “ON”. Blower
should start.
2.
Balance air flow at registers.
3. Adjust all valves to their full open position. Turn on the
line power to all heat pump units.
4. Operate unit in cooling cycle. Room temperature
should be approximately 45-100°F [7-38°C] DB. For
Start-up check, loop water temperature entering the
heat pumps should be between 45°F [7°C] and 110°F
[43°C].
5. Two factors determine the operating limits of a
Comfort-Aire/Century HKV System– (a) return air
temperature, and (b) water temperature. When any
one of these factors is at a minimum or maximum
level, the other factor must be at normal levels to
ensure proper unit operation.
a. Adjust the unit thermostat to the warmest
position. Slowly reduce thermostat setting until
the compressor activates.
b. Check for cool air delivery at the unit grille within
a few minutes after the unit has begun to operate.
Note: Units have a five minute time delay in the
control circuit that can be eliminated on the CXM
PCB as shown below in Figure 14. See controls
description for detailed features of the control.
c. Verify that the compressor is on and that the water
flow rate is correct by measuring pressure drop
through the heat exchanger using the Pete’s
plugs and comparing to Table 7.
d. Check the elevation and cleanliness of the
condensate lines. Dripping may be a sign of a
blocked line. Check that the condensate trap
includes a water seal.
e. Refer to Table 9. Check the temperature of both
supply and discharge water. If temperature is
within range, proceed with test. If temperature is
outside operating range, check cooling refrigerant
pressures in Table 8. Verify correct water flow by
comparing unit pressure drop across the heat
exchanger versus the data in Table 9. Heat of
rejection can be calculated and compared to
specification catalog.
Short test pins together
to enter Test Mode and
speed-up timing and
delays for 20 minutes.
Figure 14: Test Mode Pins
CXM Board
Unit Start Up Procedure
�
WARNING!
�
WARNING!
When the disconnect switch is closed, high
voltage is present in some areas of the electrical panel.
Exercise caution when working with energized equipment.
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CAUTION!
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INSTALLER CAUTION!
After making water connections on
units equipped with ClimaDry
®
, ensure the three union nuts
on the internal three-way water valve are tight.