Carrier 50VQP084-300 Field Control Wiring, Pre-Start-Up, A50- 6268tf.tif, A50-8441, A50-8442

Step 9 — Field Control Wiring

THERMOSTAT CONNECTIONS — The thermostat should be wired directly to the Aquazone™ control board. See Fig. 27-31.

COMPRESSOR CONTACTOR CAPACITOR COMPLETE C CONTROL

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

LINE LOAD

TRANSFORMER

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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

hammer. Figure 33 shows typical wiring for a 24-vac external solenoid valve. Figures 34 and 35 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 (on- ly on valves with end switches). Only relay or triac based elec- tronic 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.

NOTE: Low voltage connector may be removed for easy installation.

Fig. 31 — Low Voltage Field Wiring

WATER FREEZE PROTECTION — The Aquazone control allows the field selection of source fluid freeze protection points through jumpers. The factory setting of jumper JW3 (FP1) is set for water at –1.1 C. In earth loop applications, jumper JW3 should be clipped to change the setting to –12.2 C when using antifreeze in colder earth loop applications. See Fig. 32.

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AQUAZONE CONTROL (Complete C Control Shown)

Fig. 32 — Typical Aquazone™ Control Board

Jumper Locations

AIR COIL FREEZE PROTECTION — The air coil freeze protection jumper JW2 (FP2) is factory set for –1.1 C and should not need adjusting.

ACCESSORY CONNECTIONS — Terminal labeled 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. 33. Refer to the specific unit wiring schematic for details.

TERMINAL STRIP P2

C

TYPICAL

24 VAC WATER VALVE

A

Fig. 33 — Typical Aquazone Accessory Wiring

(Control D Shown)

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

C Y1

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	2	AMV
1	3	TACO VALVE
	HEATER SWITCH
C	Y1
THERMOSTAT

Fig. 34 — AMV Valve Wiring

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Fig. 35 — Taco SBV Valve Wiring

PRE-START-UP

System Checkout — When the installation is complete, follow the system checkout procedure outlined below before starting up the system. Be sure:

1.Voltage is within the utilization range specifications of the unit compressor and fan motor and voltage is balanced for 3-phase units.

2.Fuses, breakers and wire are correct size.

3.Low voltage wiring is complete.

4.Piping and system flushing is complete.

5.Air is purged from closed loop system.

6.System is balanced as required. Monitor if necessary.

7.Isolation valves are open.

8.Water control valves or loop pumps are wired.

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