Comfort-Aire HTH Series - Manual (Page 32)

32
Installation, Operation & Maintenance HTV/HTD/HTH SERIES Heat Controller, Inc.
Unit Start-Up and Operating Conditions
Unit and System Checkout
BEFORE POWERING SYSTEM, please check the following:
UNIT CHECKOUT
Balancing/shutoff valves: Insure that all isolation valves are
open and water control valves are wired.
Line voltage and wiring: Verify that voltage is within an
acceptable range for the unit and wiring and fuses/breakers
are properly sized. Verify that low voltage wiring is complete.
Unit control transformer: Insure that transformer has the
properly selected voltage tap. Residential 208-230V units are
factory wired for 230V operation unless specifi ed otherwise.
Loop/water piping is complete and purged of air. Water/
piping is clean.
Antifreeze has been added if necessary.
Entering water and air: Insure that entering water and air
temperatures are within operating limits of Table 8.
Low water temperature cutout: Verify that low water
temperature cut-out on the CXM/CXM control is properly set.
Unit fan: Manually rotate fan to verify free rotation and insure
that blower wheel is secured to the motor shaft. Be sure to
remove any shipping supports if needed. DO NOT oil motors
upon start-up. Fan motors are pre-oiled at the factory.
Check unit fan speed selection and compare to design
requirements.
Condensate line: Verify that condensate line is open and
properly pitched toward drain.
HWG pump is disconnected unless piping is completed and
air has been purged from the system.
Water fl ow balancing: Record inlet and outlet water
temperatures for each heat pump upon startup. This check
can eliminate nuisance trip outs and high velocity water fl ow
that could erode heat exchangers.
Unit air coil and fi lters: Insure that fi lter is clean and
accessible. Clean air coil of all manufacturing oils.
Unit controls: Verify that CXM fi eld selection options are
properly set. Low voltage wiring is complete.
Blower speed is set.
Service/access panels are in place.
SYSTEM CHECKOUT
System water temperature: Check water temperature for
proper range and also verify heating and cooling set points
for proper operation.
System pH: Check and adjust water pH if necessary to
maintain a level between 6 and 8.5. Proper pH promotes
longevity of hoses and fi ttings (see Table 3).
System fl ushing: Verify that all air is purged from the system.
Air in the system can cause poor operation or system
corrosion. Water used in the system must be potable quality
initially and clean of dirt, piping slag, and strong chemical
cleaning agents. Some antifreeze solutions may require
distilled water.
Flow Controller pump(s): Verify that the pump(s) is wired,
purged of air, and in operating condition.
System controls: Verify that system controls function and
operate in the proper sequence.
Low water temperature cutout: Verify that low water
temperature cut-out controls are set properly
(FP1 - JW3).
Miscellaneous: Note any questionable aspects of
the installation.
Unit Start-up Procedure
1. Turn the thermostat fan position to “ON.” Blower
should start.
2. Balance air fl ow at registers.
3. Adjust all valves to their full open position. Turn on the line
power to all heat pump units.
4. Room temperature should be within the minimum-maximum
ranges of Table 8b. During start-up checks, loop water
temperature entering the heat pump should be between 30°F
[-1°C] and 95°F [35°C].
5. Two factors determine the operating limits of water source
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 fi ve minute time delay in the control
circuit that can be bypassed on the CXM/CXM control
board as shown below in Figure 27. See controls
description for details.
c. Verify that the compressor is on and that the water fl ow
rate is correct by measuring pressure drop through the
heat exchanger using the P/T plugs and comparing to
Tables 9a through 9b.
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 fi lled to provide a water seal.
e. Refer to Table 10. 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 12. Verify correct water fl ow by comparing unit
CAUTION!
CAUTION!
CAUTION! Verify that ALL water control valves are open
and allow water fl ow prior to engaging the compressor.
Freezing of the coax or water lines can permanently
damage the heat pump.
CAUTION! To avoid equipment damage, DO NOT
leave system fi lled in a building without heat during the
winter unless antifreeze is added to the water loop. Heat
exchangers never fully drain by themselves and will
freeze unless winterized with antifreeze.