19
Unit-Powered Convenience Outlet
A unit-mounted transformer is factory-installed to step down
the main power supply voltage to the unit to 115v at the duplex
receptacle. This option also includes a manual switch with
fuse, located in a utility box and mounted on a bracket behind
the convenience outlet; access is through the unit’s control box
access panel. See Fig. 29.
The primary leads to the convenience outlet transformer are
not factory-connected. Selection of primary power source is a
customer option. If local codes permit, the transformer primary
leads can be connected at the line-side terminals on the unit-
mounted non-fused disconnect switch; this will provide service
power to the unit when the unit disconnect switch is open. Oth-
er connection methods will result in the convenience outlet cir-
cuit being de-energized when the unit disconnect switch is
open. See Fig. 33.
Fig. 33 — Powered Convenience Outlet Wiring
Fuse On Power Type
The factory fuse is a Bussman
1
“Fusetron” T-15,
non-renewable screw-in (Edison base) type plug fuse.
Test the GFCI receptacle by pressing the TEST button on the
face of the receptacle to trip and open the receptacle. Check for
proper grounding wires and power line phasing if the GFCI re-
ceptacle does not trip as required. Press the RESET button to
clear the tripped condition.
Using Unit-Mounted Convenience Outlets
Units with unit-mounted convenience outlet circuits will often
require that two disconnects be opened to de-energize all pow-
er to the unit. Treat all units as electrically energized until the
convenience outlet power is also checked and de-energization
is confirmed. Observe National Electrical Code Article 210,
Branch Circuits, for use of convenience outlets.
FACTORY-OPTION THRU-BASE CONNECTIONS (ELEC-
TRICAL CONNECTIONS)
This service connection kit consists of a
1
/
2
-in. NPT gas adapt-
er 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. bulkhead connector enables the low-voltage
control wires to pass through the basepan. The
1
/
2
-in. electrical
bulkhead connector allows the high-voltage power wires to
pass through the basepan. See Fig. 17 on page 13.
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.
UNITS WITHOUT THRU-BASE CONNECTIONS
(ELECTRICAL 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
FIELD CONTROL WIRING
The 48FC unit requires an external temperature control device.
This device can be a thermostat (field-supplied) or a System-
Vu™ controller (available as factory-installed option for use
on a Carrier 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).
THERMOSTAT
Install a Carrier-approved accessory thermostat according to
installation instructions included with the accessory. For com-
plete economizer function, select a two-stage cooling thermo-
stat. Locate the thermostat accessory on a solid wall in the con-
ditioned space to sense average temperature in accordance with
the thermostat installation instructions. Typical low-voltage
connections are shown in Fig. 34.
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. 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 [95°F (35°C) minimum]. For 50 to
75 ft (15 to 23 m), use no. 16 AWG insulated wire [95°F
(35°C) minimum]. For over 75 ft (23 m), use no. 14 AWG in-
sulated wire [95°F (35°C) 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.
1. Bussman and Fusetron are trademarks of Cooper Technologies
Company.
UNIT
VOLTAGE
CONNECT
AS
PRIMARY
CONNECTIONS
TRANSFORMER
TERMINALS
208, 230
240
L1: RED + YEL
L2: BLU + GRA
H1 + H3
H2 + H4
460
480
L1: RED
Splice BLU + YEL
L2: GRA
H1
H2 + H3
H4
575
600
L1: RED
L2: GRA
H1
H2
