Heat Controller HEV Series Installation, Operation & Maintenance Manual page 25

Heat Controller, Inc.
Accessory Connections
A terminal paralleling the compressor contactor coil
has been provided on the CXM control. Terminal "A" is
designed to control accessory devices, such as water
valves. Note: This terminal should be used only with 24
Volt signals and not line voltage. Terminal "A" is energized
with the compressor contactor. See Figure 23 or the
specific unit wiring diagram for details.
Figure 23: Accessory Wiring
Water Solenoid Valves
An external solenoid valve(s) should be used on ground
water installations to shut off flow to the unit when the
compressor is not operating. A slow closing valve may
be required to help reduce water hammer. Figure 23
shows typical wiring for a 24VAC external solenoid valve.
Figures 24 and 25 illustrate typical slow closing water
control valve wiring for Taco 500 series and Taco ESP
series valves. Slow closing valves take approximately
60 seconds to open (very little water will flow before 45
seconds). Once fully open, an end switch allows the
compressor to be energized. Only relay or triac based
electronic thermostats should be used with slow closing
valves. When wired as shown, the slow closing 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 valve can overheat the anticipator of an
electromechanical thermostat. Therefore, only relay or
triac based thermostats should be used.
HEV/H SERIES
ELECTRICAL - LOW VOLTAGE WIRING
DXM2
SBV
Figure 24: Taco Series 500 Valve Wiring
2
1
Heater Switch
Thermostat
SBV
Figure 25: Taco ESP Valve Wiring
SBV
25
Installation, Operation & Maintenance
AVM
3
Taco Valve