Carrier PSD006-070, PSV, 50PSH instruction manual Wire Field Controls, Low Voltage Field Wiring

Step 9 — Wire Field Controls

THERMOSTAT CONNECTIONS — The thermostat should be wired directly to the ECM control board. See Fig. 27.

WATER FREEZE PROTECTION — The Aquazone™ con- trol allows the field selection of source fluid freeze protection points through jumpers. The factory setting of jumper JW3 (FP1) is set for water at 30 F. In earth loop applications, jumper JW3 should be clipped to change the setting to 10 F when us- ing antifreeze in colder earth loop applications. See Fig. 28.

NOTE: The extended range option should be selected with water temperatures below 60 F to prevent internal condensation.

AIR COIL FREEZE PROTECTION — The air coil freeze protection jumper JW2 (FP2) is factory set for 30 F and should not need adjusting.

ACCESSORY CONNECTIONS — Terminal A on the control is provided to control accessory devices such as water valves, electronic air cleaners, humidifiers, etc. This signal operates with the compressor terminal. See Fig. 29. Refer to the specific unit wiring schematic for details.

NOTE: The A terminal should only be used with 24-volt signals — not line voltage signals.

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 29 shows typical wiring for a 24-vac external solenoid valve. Figures 30 and 31 illustrate typical slow closing water control valve wiring for Taco 500 Series and Taco ESP Series valves. Slow closing valves take approximately 60 sec. to open (very little water will flow before 45 sec.). Once fully open, an end switch allows the compressor to be energized (only on valves with end switches). 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 to 35 VA through the “Y” signal of the thermostat.

IMPORTANT: Connecting a water solenoid valve can overheat the anticipators of electromechanical thermo- stats. Only use relay based electronic thermostats.

COMPRESSOR CONTACTOR CAPACITOR COMPLETE C CONTROL

LINE LOAD

TRANSFORMER

a50-8197

		J1
		Y
W	R	S1
		CFM
		SW1
O		SW2
	G	SW3
		SW4
		SW5

Y2	G	SW6
		SW7
		SW8
Y1	G	SW9
		OFF	ON

G	G						G	DEHUM
		TB1
R	C	Y2 Y1 G	O	W	C	R DH AL1 A		A	AL1

THERMOSTAT CONNECTION

Fig. 27 — Low Voltage Field Wiring

TERMINAL STRIP P2

C

A

A50-6269

TYPICAL

24 VAC WATER VALVE

Fig. 29 — Typical Accessory Wiring

A50-7764

AQUAZONE CONTROL (Complete C Shown)

Fig. 28 — Typical Aquazone™ Control Board

Jumper Locations

27