48
Fig. 74 — Thermostat Wire Routing (Size 16)
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.
Electric Heaters
50TC 07-14 UNIT ELECTRIC HEATERS
NOTE: See page 49 for 50TC 16 electric heaters.
50TC*07-14 units may be equipped with field-installed acces-
sory 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 con-
tactor. One or two heater modules may be used in a unit.
Heater modules are installed in the compartment below the in-
door (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. 75-77.
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.
Fig. 75 — Typical Access Panel Location
(Sizes 07-14)
Fig. 76 — Typical Component Location (Sizes 07-14)
Fig. 77 — Typical Module Installation (Sizes 07-14)
Single Point Boxes and Supplementary Fuses
When the unit MOCP device value exceeds 60-A, unit-mount-
ed 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. 78. The single point box also in-
cludes a set of power taps and pigtails to complete the wiring
between the single point box and the unit’s main control box
terminals. Refer to the accessory heater and single point box
installation instructions for details on tap connections.
All fuses on 50TC units are 60-A. (Note that all heaters are
qualified for use with a 60-A fuse, regardless of actual heater
ampacity, so only 60-A fuses are necessary.)
Single Point Boxes without Fuses
Unit heater applications not requiring supplemental fuses re-
quire a special single point box without any fuses. The acces-
sory single point boxes contain a set of power taps and pigtails
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.
DISCONNECT MOUNTING
LOCATION
UNIT BLOCK-OFF
PANEL
OUTDOOR
ACCESS PANEL
INDOOR
ACCESS
PANEL
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
TRACK
FLANGE
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