Carrier 50LC 07, Service And Maintenance Instructions, Page: 24 / 100

24
ELECTRIC HEATERS
50LC units may be equipped with field--installed
accessory electric heaters. The heaters are modular in
design, with heater frames holding open coil resistance
wires strung through ceramic insulators, line--break limit
switches and a control contactor. One or two heater
modules may be used in a unit.
Heater modules are installed in the compartment below
the indoor (supply) fan outlet. Access is through the
indoor access panel. Heater modules slide into the
compartment on tracks along the bottom of the heater
opening. (See Fig. 28--30.)
DISCONNECT MOUNTING
LOCATION
UNIT BLOCK-OFF
PANEL OUTDOOR
ACCESS PANEL
INDOOR
ACCESS
PANEL
C08133
Fig. 28 -- Typical Access Panel Location
Not all available heater modules may be used in every
unit. Use only those heater modules that are UL listed for
use in a specific size unit. Refer to the label on the unit
cabinet for the list of approved heaters.
Unit heaters are marked with Heater Model Numbers. But
heaters are ordered as and shipped in cartons marked with
a corresponding heater Sales Package part number. See
Table 5 for correlation between heater Model Number and
Sales Package part number.
NOTE : The value in position 9 of the part number differs
between the sales package part number (value is 1) and a
bare heater model number (value is 0).
DISCONNECT
MOUNTING
LOCATION EMT OR RIGID CONDUIT
(FIELD-SUPPLIED) SINGLE
POINT BOX CENTER
POST
HEATER
COVERS
HEATER
MOUNTING
BRACKET HEATER
MODULE
(LOCATION 2) HEATER
MODULE
(LOCATION 1)
SINGLE POINT
BOX
MOUNTING
SCREW
BRACKET AND
CONDUIT
DRIP BOOT MAIN
CONTROL
BOX
CONTROL WIRE TERMINAL BLOCK
MANUAL RESET
LIMIT SWITCH
C08134
Fig. 29 -- Typical Component Location
TRACK
FLANGE
C08135
Fig. 30 -- Typical Module Installation
Single Point Boxes and Supplementary Fuses
When the unit MOCP device value exceeds 60--A,
unit--mounted supplementary fuses are required for each
heater circuit. These fuses are included in accessory
Single Point Boxes, with power distribution and fuse
blocks. The single point box will be installed directly
under the unit control box, just to the left of the partition
separating the indoor section (with electric heaters) from
the outdoor section. The Single Point Box has a hinged
access cover. (See Fig. 31.) The Single Point Box also
includes a set of power taps to complete the wiring
between the Single Point Box and the unit’s main control
box terminals. Refer to accessory heater and Single Point
Box installation instructions for details on tap
connections.