Carrier Aquazone 50PCH007 Installation, Start-Up And Service Instructions Manual page 22

Step 9 — Wire Control Connections
COMPLETE C AND DELUXE D CONTROL
All control wiring is connected to a terminal block located in the
unit electrical box. Refer to the unit wiring diagram for connection
details.
WARNING
To avoid possible injury or death due to electrical shock, open
the power supply disconnect switch and secure it in an open
position during installation.
CAUTION
Never route control wiring through the same conduit as power
supply wiring. Electrical noise and transients from the power
wiring can cause communication issues or damage to the con-
trol wiring and connected control components.
The units with the Complete C or Deluxe D control package can
be controlled using the included thermostat inputs (R, O, Y1, C,
G) for single stage heat pump thermostat or field-installed DDC
(Direct Digital Controls) controls. Note that the reversing valve on
the unit is energized when the unit is in the cooling mode. See
Fig. 19 for typical thermostat connections.
C O Y
Fig. 19 — Typical Thermostat Connections
THERMOSTAT AND DDC SENSORS
Thermostats or DDC space sensors should be located on an interi-
or wall away from supply ducts. Avoid locations subject to direct
sunlight or drafts, or external walls. Thermostat wiring should be
18 AWG (American Wire Gage). Refer to the installation instruc-
tions for the thermostat for further details.
IMPORTANT: Exceptionally long runs of thermostat wire
should be avoided to prevent voltage drops in the control
circuit.
HOT GAS REHEAT CONTROL
Units with hot gas reheat (HGRH) will include an additional H
terminal on the input terminal board for dehumidification control.
To enable a call for dehumidification, a 24V signal must be sent to
the H terminal with no voltage applied to the Y1 or O terminals.
Any call for cooling (Y1 and O) will override the dehumidifica-
tion call.
G
R
AUXILIARY RELAY (DELUXE D ONLY)
All units with Deluxe D control include an auxiliary relay that can
be field wired to enable a field provided loop pump or solenoid
valve when there is a call for compressor operation. See Fig. 14.
ENERGY MANAGEMENT SWITCH (DELUXE D ONLY)
All units with Deluxe D control include an energy management
switch (EMS) relay that can be field wired to disable unit opera-
tion when a 24V signal is removed from the relay. Removing the
24V signal causes the relay to open, which cuts 24V power to the
unit control circuit. All unit components will be disabled at when
the EMS is deactivated. See Fig. 14.
NOTE: Units with constant torque ECM motors may experience a
30 second delay between when the EMS is activated and when the
blower finally shuts off. Constant torque ECM blowers are factory
programmed with a 30 second delay when losing the control sig-
nal, to prevent nuisance shut downs.
BOILERLESS HEAT CONTROL (DELUXE D ONLY)
All units with Deluxe D control include a boilerless heat relay that
can be field wired to enable an external heat source when the wa-
ter loop temperature drops below the boilerless heat control set
point. See Fig. 14.
ALARM OUTPUT (ALL UNITS)
If the unit is being connected to a thermostat or DDC control with
an alarm indicator, this connection is made at the unit malfunction
output on the Unit Protection Module (UPM). See the Unit Protec-
tion Module heading in the Set Up Unit Controls section for fur-
ther details.
WSHP OPEN CONTROL
WSHP Open is a factory installed DDC control that requires the
use of Carrier ZS or WS sensors or the Carrier Equipment Touch
or System Touch for space temperature sensing. WSHP Open is
not compatible with thermostats or 3rd party temperature sensors.
All WSHP Open wiring is completed at the WSHP Open control
board. See Fig. 18 for details. For further instructions on WSHP
Open, please visit HVACPartners.com or Carrier.com for the
WSHP Open V4 Integration Guide and Points/Properties Guide.
CONTROL TRANSFORMER
All units with Complete C control and without HGRH or water-
side economizer include a 50VA transformer. All units with Com-
plete C control and with HGRH or waterside economizer use a
75VA transformer. All units with Deluxe D control or WSHP
Open include a 75VA transformer.
Exceeding the transformer capacity can result in low control
voltage, erratic unit operation or damage to the heat pump.
The VA capacity of the transformer should be considered when
applying low voltage accessories, such as shut off valves, thermo-
stats, or DDC controls. Table 6 shows the VA draw of factory-
mounted components in the low voltage heat pump. The total VA
draw of the heat pump internal components plus any attached ac-
cessories must be lower than the VA capacity of the unit control
transformer.
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CAUTION