Low Voltage Wiring - Carrier AQUAZONE 50KQE Series Installation, Operation And Maintenance Instructions

3.4.2 - 220-Volt operation
All 220-240-Volt units are factory wired for 240 Volts. The trans-
formers may be switched to 220-Volt operation (as illustrated in
the wiring diagram) by switching the red (220-Volt) wire with
the orange (240-Volt) wire at the PB(1) terminal.
Fig. 8 - Typical field-installed wiring
A
Heat pump
HEAT PUMP
A = Two power wires for single-phase units.
B = 1 heat/1 cool/manual or auto changeover remote 24-V thermostat.
Note: All customer-supplied wiring to be copper only and must conform to national
and local electrical codes. Wiring shown with dashed lines must be field-supplied
and field-installed. "B" wiring only required with systems using remote-mounted
thermostats.
CAUTION: Use copper conductors only to prevent equipment
damage.
WARNING: Disconnect electrical power source to prevent
injury or death from electrical shock.

3.5 - Low voltage wiring

3.5.1 - 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 appli-
cations, jumper JW3 should be clipped to change the setting to
-12.2°C when using anti-freeze in colder earth loop applications
(see Fig. 9).
3.5.2 - 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. 10).
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.
3.5.3 - Water solenoid valves
Water solenoid valves may be used on variable flow systems
and ground water installations. A typical well water control valve
wiring approach, which can limit waste water in a lockout con-
dition, is shown in Fig. 10. A slow-closing valve may be required
to prevent water hammer. When using a slow-closing valve,
consider special wiring conditions. The valve takes approximately
60 seconds 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.
IMPORTANT: Connecting a water solenoid valve can overheat
the anticipators of electromechanical thermostats. Only use
relay based electronic thermostats.
Field-supplied
FIELD SUPPLIED
disconnect switch
DISCONNECT SWITCH
Room thermostat
ROOM THERMOSTAT
B
3.5.4 - Optional wall-mounted thermostat
The 50KQE water-source heat pump units are built with
standard internal thermostats in either manual changeover
(MCO) or automatic changeover (ACO) configuration (refer to
Figs. 11-14).
When desired, the unit can be furnished with a 24-Volt control
circuit which is field-wired to a Carrier-supplied accessory
remote thermostat. Most heat pump thermostats can be used
with the controller. Use a thermostat with Y, G, O and W
outputs. Refer to unit wiring diagrams in Figs. 15 and 16 and
Aquazone controls, operation and troubleshooting instructions
for additional information.
Vendor installation instructions and additional installation
information is shipped with each thermostat.
NOTE: Low-voltage wiring between the unit and the wall
thermostat must comply with all applicable electrical codes
(i.e., national and local codes), and be completed before the
unit is installed.
Table 3 lists recommended wire sizes and lengths to install the
thermostat. The total resistance of low-voltage wiring must not
exceed 1 ohm. Any resistance in excess of 1 ohm may cause the
control to malfunction because of high voltage drop.
Table 3 - Recommended thermostat wire sizes
Wire size
18-Gauge
16-Gauge
14-Gauge
* Length = Physical distance from thermostat to unit.
Fig. 9 - Typical Aquazone control board jumper
Clip JW3
when using
anti-freeze
Clip for dry
contact
between
AL1-AL2
Aquazone control (complete control shown)
Fig. 10 - Typical Aquazone accessory wiring
Terminal Strip
Terminal strip
C
A
Max. wire length*
23 m
38 m
62 m
locations
Comp.
relay
Off On
Test
Dip switches
Status
LED
Alarm
relay
Typical
24 V a.c. Typical water valve
Water
24 VAC
Valve
11