Carrier 50TCQA User Manual
Page 14
14
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
C08637
Fig. 20 -- Thru--Base Connection Fittings
Field--supplied and field--installed liquidtight 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. 16.
All Units —
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See
Table 10. 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 Table 10, Note 2 (see
page 44) 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 50TCQA unit requires an external temperature
control device. This device can be a thermostat
(field--supplied) or a PremierLink controller (available as
factory--installed option or as field--installed accessory, for
use on a Carrier Comfort Network or as a stand alone
control) or the RTU--MP Controller for Building
Management
Systems
using
non--CCN
protocols
(RTU--MP is available as a factory--installed option only).
Thermostat —
Install
a
Carrier--approved
accessory
2
stage
Cooling/Heating thermostat according to installation
instructions included with the accessory. The 50TCQ
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.
X
C
G
W2
C
W2
G
W1
O/B/Y2
Y2
R
W1
R
Y1
Y1
T
H
E
R
M
O
S
T
A
T
(Note 1)
(Note 2)
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
Central
Terminal
Board
Typical
Thermostat
Connections
C09012
Fig. 21 -- Typical Low--Voltage Control Connections
Unit without thru--base connection kit —
Pass the thermostat control wires through the hole
provided in the corner post; then feed the wires through
the raceway built into the corner post to the control box.
Pull the wires over to the terminal strip on the upper--left
corner of the Central Terminal Board (CTB). See Fig. 22.
NOTE:
If thru--the--bottom connections accessory is
used, refer to the accessory installation instructions for
information on routing power and control wiring.
Heat Anticipator Settings —
Set heat anticipator settings at 0.14 amp for the first stage
and 0.14 amp for second--stage heating, when available.
50TC
Q
A