Heat Controller, Inc.
HKV LArge CommerCiAL
IOM Instructions
14
C
C
Termostato
Y
1
2
3
Y
AVM
Taco Válvula
Calentador Interruptor
Unidad Empacada
C
C
Thermostat
Y1
1
2
3
Y1
AVM
Taco Valve
Heater Switch
Low Water Temperature Cutout - FP1
The CXM control allows the field selection of source fluid low
temperature cutout points. The factory setting of FP1 is set for
water (30°F [-1.1°C]). In cold temperature applications jumper
JW3 (FP1- antifreeze 10°F [-12.2°C]) should be clipped as
shown in Figure 8 to change the setting to 10°F [-12.2°C], a more
suitable temperature when using antifreezes. It should be noted
that the extended range option should be specified to operate the
HB Series at entering water temperatures below 60°F [15°C].
Accessory Connections
A terminal paralleling the compressor contactor coil has been
provided on the CXM control board. “A” has been provided to
control accessory devices, such as water valves, electronic
air cleaners, humidifiers, etc.
Note: This terminal must be
used only with 24 Volt signals and not line voltage sig-
nals.
This signal operates with the compressor contactor. See
Figure 9 or the wiring schematic for details.
Water Solenoid Valves
When using external solenoid valves on ground water
installations, a slow closing valve may be desired. Figure 9
illustrates a typical slow closing water control valve wiring
which will limit wasted water during a lockout condition. A slow
Figure 10: Well Water AVM Valve Wiring
CXM/DXM #1
HKV Unit
Electrical - Low Voltage
CAUTION!
CAUTION!
For units with manual or electric water shut-off
valve.
DAMAGE WILL OCCUR
if shut-off valve is
closed
during unit operation. A high pressure switch must be installed
on the heat pump side of any field provided shut-off valves
and connected to the heat pump controls in series with the
built-in refrigerant circuit high pressure switch to disable
compressor operation if water pressure exceeds pressure
switch setting. The field installed high pressure switch shall
have a cut-out pressure of 300 psig and a cut-in pressure of
250 psig.
closing valve may be required to prevent water hammer.
When using an AVM -Taco Slow Closing valve on HKV
Series equipment Figure 10 wiring should be utilized. The
valve takes approximately 60 seconds to open (very little
water will flow before 45 seconds) and it activates the
compressor only after the valve is completely opened (by
closing its end switch). Only relay or triac based electronic
thermostats should be used with the AVM valve. When
wired as shown, the valve will operate properly with the
following notations:
1-The valve will remain open during a unit lockout.
2-The valve will draw approximately 25-35 VA through the
“Y” signal of the thermostat. Note: This can overheat the
anticipators of electromechanical thermostats. Therefore
only relay or triac based thermostats should be used.
Figure 8: FP1 Jumper
Figure 9: 24 Volt Accessory Wiring
These terminals may be
used to power 24 volt
water valves on units
size 084-150. Refer to
Figure 9a for water valve
wiring to dual compres-
sor units.
CXM Terminal Strip
