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Fig. 26 − Thru−Base Connection Fittings
Check tightness of connector lock nuts before connecting
electrical conduits.
Field−supplied and field−installed liquid−tight conduit
connectors and conduit may be attached to the connectors
on the basepan. Pull correctly rated high voltage and low
voltage through appropriate conduits. Connect the power
conduit to the internal disconnect (if unit is so equipped)
or to the external disconnect (through unit side panel). A
hole must be field cut in the main control box bottom on
the left side so the 24−v control connections can be made.
Connect the control power conduit to the unit control box
at this hole.
Units without Thru−Base Connections —
1. Install power wiring conduit through side panel open-
ings. Install conduit between disconnect and control
box.
2. Install power lines to terminal connections as shown
in Fig. 18.
All Units −
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See
Tables 15 and 16. On 3−phase units, voltages between
phases must be balanced within 2% and the current within
10%. Use the formula shown in the legend for Tables 15
and 16, Note 3 (see page 42) to determine the percent of
voltage imbalance. Operation on improper line voltage or
excessive phase imbalance constitutes abuse and may
cause damage to electrical components. Such operation
would invalidate any applicable Carrier warranty.
Field Control Wiring —
The 50HCQ unit requires an external temperature control
device. This device can be a thermostat (field−supplied) or a
PremierLinkt controller (available as factory−installed
option or as field−installed accessory, for use on a Carrier
R
Comfort Network
or as a stand alone control) or the RTU
Open Controller for Building Management Systems using
non−CCN protocols (RTU Open controller is available as a
factory−installed option only).
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
C13412
Thermostat —
Install
a
Carrier−approved
Cooling/Heating
thermostat according to installation
instructions included with the accessory. The 50HCQ
models do not require a thermostat with an O function to
control the reversing valve operation. If using an
electronic thermostat, configure it for "non−heat pump"
operation. Locate the thermostat accessory on a solid wall
in the conditioned space to sense average temperature in
accordance with the thermostat installation instructions.
If the thermostat contains a logic circuit requiring 24−v
power, use a thermostat cable or equivalent single leads of
different colors with minimum of seven leads. If the
thermostat does not require a 24−v source (no "C"
connection required), use a thermostat cable or equivalent
with minimum of six leads. Check the thermostat
installation instructions for additional features which
might require additional conductors in the cable.
For wire runs up to 50 ft. (15 m), use no. 18 AWG
(American Wire Gage) insulated wire (35_C minimum).
For 50 to 75 ft. (15 to 23 m), use no. 16 AWG insulated
wire (35_C minimum). For over 75 ft. (23 m), use no. 14
AWG insulated wire (35_C minimum). All wire sizes
larger than no. 18 AWG cannot be directly connected to
the thermostat and will require a junction box and splice
at the thermostat.
Typical
Thermostat
Connections
C
G
W2
(Note 2)
W1
O/B/Y2
(Note 1)
Y1
R
Note 1: Typical multi-function marking. Follow manufacturer's configuration
instructions to select Y2. Do not configure for O output.
Note 2: W2 connection not required on units without electric heating.
Field Wiring
Fig. 27 − Typical Low−Voltage Control Connections
Central Terminal Board
The Central Terminal Board (CTB) is a pass through
connection point. The CTB provides the capability to add
factory−installed options and field−installed accessories to
the units by cutting jumper wires without having to
change or reroute wires through the structure of the unit.
20
accessory
2
stage
Central
Terminal
Board
X
C
T
H
G
E
R
W2
M
O
W1
S
T
Y2
A
T
Y1
R
C09012
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