Heat Controller HEV/H Electrical - Low Voltage Wiring, Hev/H Series, Accessory Wiring, Wbmwf B

Heat Controller, Inc. HEV/H SERIES Installation, Operation & Maintenance

ELECTRICAL - LOW VOLTAGE WIRING

Accessory Connections

A terminal paralleling the compressor contactor coil has been provided on the DXM2 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

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B

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 SBV 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.

Figure 24: Taco Series 500 Valve Wiring

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C Y1

Thermostat

Figure 25: Taco ESPSBVValve Wiring

SBV

25