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FACTORY-OPTION THRU-BASE CONNECTIONS (ELEC-
TRICAL CONNECTIONS)
This service connection kit consists of a
head connector and a
3
/
-in. electrical bulkhead connector, all
4
factory-installed in the embossed (raised) section of the unit
basepan in the condenser section. The
tor enables the low-voltage control wires to pass through the
basepan. The
1
/
-in. electrical bulkhead connector allows the
2
high-voltage power wires to pass through the basepan. See
Fig. 25.
Check tightness of connector lock nuts before connecting elec-
trical conduits.
Field-supplied and field-installed liquid tight conduit connec-
tors and conduit may be attached to the connectors on the base-
pan. 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 connec-
tions can be made. Connect the control power conduit to the
unit control box at this hole.
Fig. 25 — Thru-Base Connection Fittings
UNITS WITHOUT THRU-BASE CONNECTIONS (ELEC-
TRICAL CONNECTIONS)
1.
Install power wiring conduit through side panel openings.
Install conduit between disconnect and control box.
2.
Install power lines to terminal connections as shown in
Fig. 20 on page 14.
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. On 3-phase
units, voltages between phases must be balanced within 2%
and the current within 10%. Use the formula shown in the ex-
ample below to determine the percent of voltage imbalance.
Operation on improper line voltage or excessive phase imbal-
ance constitutes abuse and may cause damage to electrical
components. Such operation would invalidate any applicable
Carrier warranty.
1
/
-in. electrical bulk-
2
3
/
-in. bulkhead connec-
4
LOW VOLTAGE
CONDUIT
CONNECTOR
HIGH VOLTAGE
CONDUIT
CONNECTOR
Example: Supply voltage is 230-3-60
A
B
C
AB = 224 v
BC = 231 v
AC = 226 v
MOTOR
Average Voltage
=
Determine maximum deviation from average voltage.
(AB) 227-224 = 3 v
(BC) 231-227 = 4 v
(AC) 227-226 = 1 v
Maximum deviation is 4 v.
Determine percent of voltage imbalance.
% Voltage Imbalance = 100 x
This amount of phase imbalance is satisfactory as it is below the
maximum allowable 2%.
IMPORTANT: If the supply voltage phase imbalance is
more than 2%, contact your local electric utility company
immediately.
FIELD CONTROL WIRING
The 50HCQ unit requires an external temperature control de-
vice. This device can be a thermostat (field-supplied) or a Pre-
mierLink™ controller (available as factory-installed option or
as field-installed accessory, for use on a Carrier Comfort Net-
work
®
or as a stand-alone control) or the RTU Open Controller
for Building Management Systems using non-CCN protocols
(RTU Open is available as a factory-installed option only).
THERMOSTAT
Select a Carrier-approved accessory 2-stage Cooling/Heating
thermostat. 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. Install the accessory thermostat according to
installation instructions included with the accessory.
Locate the thermostat accessory on a solid wall in the condi-
tioned 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 ther-
mostat cable or equivalent with minimum of six leads. See Fig.
26. Check the thermostat installation instructions for additional
features which might require additional conductors in the ca-
ble.
For wire runs up to 50 ft. (15 m), use no. 18 AWG (American
Wire Gage) insulated wire [35°C (95°F) minimum]. For 50 to
75 ft. (15 to 23 m), use no. 16 AWG insulated wire [35°C
(95°F) minimum]. For over 75 ft. (23 m), use no. 14 AWG in-
sulated wire [35°C (95°F) minimum]. 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.
16
(224 + 231 + 226)
681
=
3
3
4
=
227
=
227
1.78%
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