Comfort-Aire HWW120 - Manual (Page 26)

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Installation & Operation WATER-TO-WATER (HWW) SERIES Heat Controller, Inc.
Unit Start Up Procedures
Table 5: Water Temperature Change
Through Source Heat Exchanger
Note: Units have a five minute time delay in the control
circuit that can be eliminated on the CXM PCB as shown
in Figure 9 [Page 20]. See controls description for detailed
features of the control.
1. Adjust all valves to their full open position. Turn on the
line power to all heat pump units.
2. Operate each unit in the cooling cycle. Loop water
temperature entering the heat pumps should be be-
tween 70°F [21°C] and 110° F [43°C].
3. Operate each heat pump in the heating cycle imme-
diately after checking cooling cycle operation. A time
delay will prevent the compressor from re-starting for
approximately five (5) minutes.
4. Establish a permanent operating record by logging the
unit operating conditions at initial start-up for each unit.
5. If a unit fails to operate, conduct the following checks:
a. Check the voltage and current. They should com-
ply with the electrical specifications described on
the unit nameplate.
b. Look for wiring errors. Check for loose terminal
screws where wire connections have been made
on both the line and low-voltage terminal boards.
c. Check the supply and return piping. They must be
properly connected to the inlet and outlet connec-
tions on the unit.
d. If the checks described above fail to reveal the
problem and the unit still will not operate, contact
a trained service technician to ensure proper diag-
nosis and repair of the equipment.
� 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.
� WARNING! �
Verify ALL water controls are open and allow water flow
prior to engaging the compressor. Freezing of the coax
or water lines can permanently damage the heat pump.
Water Flow, gpm [l/m]
Rise, Cooling
°F, [°C]
Drop, Heating
°F, [°C]
For Closed Loop: Ground Source or
Closed Loop Systems at 3 gpm per
ton [3.9 l/m per kW]
9 - 12
[5 - 6.7]
4 - 8
[2.2 - 4.4]
For Open Loop: Ground Water
Systems at 1.5 gpm per ton
[2.0 l/m per kW]
20 - 26
[11.1 - 14.4]
10 - 17
[5.6 - 9.4]