Heat Controller HTV Series - Two factors determine the operating limits

Heat Controller, Inc. HTV/HTD/HTH SERIES
38
UNIT STARTING AND OPERATING CONDITIONS
35
T
CAUTION! Verify that ALL water
control valves are open and allow
water flow prior to engaging the
compressor. Freezing of the coax or
water lines can permanently damage
the heat pump.
⌧ CAUTION! ⌧
T
CAUTION! To avoid equipment
damage, DO NOT leave system filled
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.
⌧ CAUTION! ⌧
NOTICE! Failure to remove shipping
brackets from spring-mounted
compressors will cause excessive
noise, and could cause component
failure due to added vibration.
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
heat pump
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 and
95°F.
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 control
board as shown below in Figure 17
on Page 37. 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
Table 8.
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. Refer to Table 7. 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 Table 9.
Verify correct water flow by
comparing unit pressure drop
across the heat exchanger versus
the data in Table 8.