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14
Step 8 — Low Voltage Wiring
THERMOSTAT CONNECTIONS — The thermostat should
be wired directly to the Aquazone™ control board. See
Fig. 4 and 5.
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 30 F. In earth loop applications, jumper
JW3 should be clipped to change the setting to 13 F when
using antifreeze in colder earth loop applications. See Fig. 6.
AIR COIL FREEZE PROTECTION —
The air coil freeze
protection jumper JW2 (FP2) is factory set for 30 F and should
not need adjusting, unless using anti-freeze.
ACCESSORY CONNECTIONS —
Terminal labeled A on
the control is provided to control accessory devices such as
water valves, electronic air cleaners, humidifiers, etc. This sig-
nal operates with the compressor terminal. See Fig. 7. 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 — Water solenoid valves may
be used on primary secondary pump and ground water installa-
tions. A typical well water control valve wiring which can
limit waste water in a lockout condition is shown in Fig. 7. A
slow closing valve may be required to prevent water hammer.
When using a slow closing valve, special wiring conditions
need to be considered. The valve takes approximately 60 sec-
onds to open (very little water will flow before 45 seconds) and
it activates the compressor only after the valve is completely
opened by closing its end switch. When wired as shown, the
valve will have the following operating characteristics:
1. Remain open during a lockout.
2. Draw approximately 25 to 35 VA through the “Y” signal
of the thermostat.
PRE-START-UP
System Checkout —
When the installation is complete
and the system is cleaned and flushed, follow the System
Checkout procedure outlined below.
1. Voltage: Ensure that the voltage is within the utilization
range specifications of the unit compressor and fan motor.
2. System Water Temperature: Ensure that the system
water temperature is within an acceptable range to facili-
tate start-up. (When conducting this check, also verify
proper heating and cooling set points.)
3. System Water pH: Verify system water acidity
(pH = 7.5 or 8.5). Proper pH promotes the longevity of
hoses and heat exchangers.
4. System Flushing: Properly clean and flush the system
periodically. Ensure that all supply and return hoses are
connected end-to-end to facilitate system flushing and
prevent fouling of the heat exchanger by system water.
Water used in the system must be potable and should not
contain dirt, piping slag, and chemical cleaning agents.
5. Closed-Type Cooling Tower or Open Tower with Heat
Exchanger: Check equipment for proper temperature set
points and operation.
6. Verify Balanced Water Flow Rate to Heat Pump.
7. Standby Pump: Verify that the standby pump is properly
installed and in operating condition.
8. Access Panels: Assure that all access panels in the filter
and fan section are securely closed.
9. Air Dampers: Assure that all air dampers are properly
set.
IMPORTANT: This can overheat the anticipators of
electromechanical thermostats. Only use relay based
electronic thermostats.
Capacitor
Circ Brkr
Grnd
Contactor-CC
L2
L1
Transformer
CB
Aquazone “C”
See Note
Low Voltage
Connector
THERMOSTAT
WIRED DIRECTLY
TO CONTROL
BOARD
BR
NOTE: Low voltage connector may be removed for easy installation.
Fig. 5 — Low Voltage Field Wiring
Typical
Water
Valve
C
A
24 VAC
Terminal Strip P2
AQUAZONE CONTROL (C Control Shown)
Fig. 6 — Typical Aquazone Control Board
Jumper Locations
Fig. 7 — Typical D Control Accessory Wiring