Comfort-Aire HBH Series 6-10 Tons - Manual (Page 39)

Heat Controller, Inc. HBH SERIES IOM Manual
38
Unit Start-Up Procedure
Unit Start-up Procedure
1. Turn the thermostat fan position to “ON”. Blower should
start.
2. Balance air flow at registers.
3. Adjust all valves to their full open positions. Turn on the line
power to all heat pumps.
4. Room temperature should be within the minimum-maximum
ranges of table 9. During start-up checks, loop water
temperature entering the heat pump should be between
60°F [16°C] and 95°F [35°C].
5. Two factors determine the operating limits of Heat
Controller heat pumps, (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 level to insure proper unit operation.
a. Adjust the unit thermostat to the warmest setting.
Place the thermostat mode switch in the “COOL”
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
control board as shown below in Figure 28. See
controls description for details.
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 P/T plugs
and comparing to tables 10a through 10e.
d. Check the elevation and cleanliness of the
condensate lines. Dripping may be a sign of a
blocked line. Check that the condensate trap is
filled to provide a water seal.
e. Check the temperature of both entering and
leaving water. If temperature is within range table,
proceed with the test. If temperature is outside of
the operating range, check refrigerant pressures
and compare to tables 12 through 15. Verify correct
water flow by comparing unit pressure drop across
the heat exchanger versus the data in tables
10a through 10e. Heat of rejection (HR) can be
calculated and compared to submittal data capacity
pages. The formula for HR for systems with water
is as follows:
HR (Btuh) = TD x GPM x 500, where TD is the
temperature difference between the entering and
leaving water, and GPM is the flow rate in U.S.
GPM, determined by comparing the pressure drop
across the heat exchanger to tables 8a through 8e.
In S.I. units, the formula is as follows: HR (kW) =
TD x l/s x 4.18.
f. Check air temperature drop across the air coil when
compressor is operating. Air temperature drop
should be between 15°F and 25°F [8°C and 14°C].
g. Turn thermostat to “OFF” position. A hissing noise
indicates proper functioning of the reversing valve.
6. Allow five (5) minutes between tests for pressure to
equalize before beginning heating test.
a. Adjust the thermostat to the lowest setting. Place the
thermostat mode switch in the “HEAT” position.
b. Slowly raise the thermostat to a higher temperature
until the compressor activates.
c. Check for warm air delivery within a few minutes
after the unit has begun to operate.
d. Refer to table 17. Check the temperature of both
entering and leaving water. If temperature is within
range, proceed with the test. If temperature is
outside of the operating range, check refrigerant
pressures and compare to tables 11 through 16.
Verify correct water flow by comparing unit pressure
drop across the heat exchanger versus the data
in tables 10a through 10e. Heat of extraction (HE)
can be calculated and compared to submittal data
capacity pages. The formula for HE for systems with
water is as follows:
HE (Btuh) = TD x GPM x 500, where TD is the
temperature difference between the entering and
leaving water, and GPM is the flow rate in U.S. GPM,
determined by comparing the pressure drop across
the heat exchanger to tables 10a through 10e. In S.I.
units, the formula is as follows: HE (kW) = TD x l/s x
4.18.
e. Check air temperature rise across the air coil when
compressor is operating. Air temperature rise should
be between 20°F and 30°F [11°C and 17°C].
f. Check for vibration, noise, and water leaks.
7. If unit fails to operate, perform troubleshooting analysis
(see troubleshooting section). If the check described fails
to reveal the problem and the unit still does not operate,
contact a trained service technician to insure 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 HEAT
CONTROLLER.
Note: If performance during any mode appears abnormal,
refer to the CXM section or troubleshooting section of
this manual. To obtain maximum performance, the air
coil should be cleaned before start-up. A 10% solution of
dishwasher detergent and water is recommended.