Heat Controller HTS SERIES Electrical - Low Voltage, Heat Controller, Inc. Water-Sourceheat Pumps

HEAT CONTROLLER, INC. WATER-SOURCE HEAT PUMPS

R e s i d e n t i a l S p l i t - 6 0 H z R 4 1 0 A

R e v. : 0 3 A u g u s t , 2 0 1 2

Electrical - Low Voltage

Figure 22: HTS Low Voltage Field Wiring

Low Voltage Field Wiring

Low Water Temperature Cutout Selection

The DXM2 control allows the field selection of low water (or water-antifreeze solution) temperature limit by clipping jumper JW3, which changes the sensing temperature associated with thermistor LT1. Note that the LT1 thermistor is located on the refrigerant line between the coaxial heat exchanger and expansion device (TXV). Therefore, LT1 is sensing refrigerant temperature, not water temperature, which is

a better indication of how water flow rate/temperature is affecting the refrigeration circuit.

The factory setting for LT1 is for systems using water (30°F [-1.1°C] refrigerant temperature). In low water temperature (extended range) applications with antifreeze (most ground loops), jumper JW3 should be clipped as shown in Figure 23 to change the setting to 10°F [-12.2°C] refrigerant temperature, a more suitable temperature when using

an antifreeze solution. All residential units include water/ refrigerant circuit insulation to prevent internal condensation, which is required when operating with entering water temperatures below 59°F [15°C].

Figure 23: LT1 Limit Setting

		HP
Fault	Status	LP
		LP
		LT1
		LT1

Accessory Connections

A terminal paralleling the compressor contactor coil has been provided on the DXM2 control. Terminal “A” is designed to control accessory devices. Note: This terminal should be used only with 24 Volt signals and not line voltage. Terminal “A” is energized with the compressor contactor.

Figure 23a: Accessory Wiring

Terminal Strip

C
DXM2	24VAC
P2

A

Motorized Modulating Water Control Valve - Open Loop Ground Water Systems Only

An external valve should be used on ground water systems to shut off flow when the compressor is not operating. Valve kit AMMV4D is available for use with HTS024-048, and kit AMMV5E is used with HTS060. See Figure 23b or the unit wiring diagram for valve wiring detail. Further details on valve operation are described later in this manual.

Figure 23b: Motorized Modulating Water Control Valve - Open Loop Ground Water Systems Only

P3

DXM 2

P11

For MWV option, place jumper on 0-10V pins.

c1 ay

c2 ay

Off On

1 2 3 4

S3 Off On

1 2 3 4 5 6 7 8

S1

Off On

1 2 3 4 5 6 7 8

S2

A0-1 A0-2

		LT2
JW3		LT2
		RV
		RV
	12	CO
		CO
	RV	P7
CCH	Relay
	1	24Vdc
Relay
	4	EH1
		EH2
	Comp	P6
	Relay
		CCG

JW3-LT1

jumper should

be clipped

for low

temperature

(antifreeze)

operation

Ensure actuator direction switch is set as shown.

P11

P10

P9

CC

AO2 Gnd

T1

T2

T2

T3

T3

T4

T4

T5

T5

T6

T6

DXM2 PCB

24 Heat Controller, Inc. Water-Source Heating and Cooling Systems