13
Factory--Option Thru--Base Connections —
This service connection kit consists of a 1/2 -- in NPT gas
adapter fitting (brass), a 1/2--in electrical bulkhead
connector and a 3/4--in electrical bulkhead connector, all
factory--installed in the embossed (raised) section of the
unit basepan in the condenser section. The 3/4--in
bulkhea d connector enable s the low--voltage control wires
to pass through the basepan. The 1/2--in electrical
bulkhea d connector allows the high--voltage power wires
to pass through the basepan. See Fig. 14.
Check tightness of c onnector lock nuts before connecting
electrical condui ts.
Field--supplied and field--installed l iquid tight conduit
connec tors and conduit may be attached to the connectors
on the basepan. Pull correctly rated high voltage and low
voltage through appropriate c onduits. Connect the power
conduit to the internal disconnec t (i f 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 disconne ct and control
box.
2. Install power line s to terminal connections as shown
in Fig. 21.
Voltage to compressor terminals during operation must be
within voltage range indicated on unit nameplate. See
Table 2. 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 2, Note 2 to
determine the percent of voltage imbalance. Operation on
improper line voltage or excessive phase imbalance
constitutes abuse and may cause damage to electrical
compone nts. Such operation would i nvalidate any
applicable Carrier warranty.
Field Control Wiring —
The 48TC 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 al one control) or a Local
Equipment Interface (LEI) card that will communicate
with a Building Management System using non--CCN
protocols (LEI card also available as factory--installed
option or as field--installed accessory).
Thermostat —
Install a Carrier--approved accessory thermostat according
to installation instructions included with the accessory.
For complete economizer function, select a two--stage
cooling thermostat. 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 thermosta t c ontains 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”
connec tion required), use a thermostat cable or equivalent
with minimum of six leads. Check the thermostat
installation instructions for additional features which
might require addit ional conductors in the cable.
For wire runs up to 50 ft. (15 m), use no. 18 AWG
(American Wi re Gage) insulated wire (35 --deg C
minimum). For 50 to 75 ft. (15 to 23 m), use no. 16 AWG
insulated wire (35-- deg C minimum). For over 75 ft. (23
m), use no. 14 AWG insulated wire (35--deg C minimum).
All wire sizes larger than no. 18 AWG cannot be direct ly
connec ted to the thermostat and will require a junction
box and splice at the thermostat.
WIRE
CONNECTIONS
TO
LOW-VOLTAGE
SECTION
COOL STAGE 1
FA N
HEAT STAGE 1
COOL STAGE 2
HEAT STAGE 2
24 VAC HOT
24 VAC COM
N/A
OUTDOOR AIR
SENSOR
Y1/W2
G
W/W1
Y/Y2
O/W2
R
C
S1
S2
THERMOSTAT DIPSWITCH SETTINGS
R
G
Y1
Y2
W1
W2
C
IFO/X
ON
OFF
A
B
C
D
LEGEND
NOTE: Underlined letter indicates active thermostat output when
configured for A/C operation.
Field Wiring
C07102
Fig. 22 -- Low--Voltage 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.
48TC
To Next Page
Loading...
