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Shorting the jumpers for a period of 1 to 3 seconds
reduces the defrost timer periods by a factor of 0.1
sec/minute. (For example, the 90 minute run period is
reduced to 9 seconds) The DFB will step the unit through
a Heating cycle and a Defrost cycle using these reduced
time periods. This mode ends after the Defrost cycle.
Table 8. Dip Switch Position
Switch No.
1
2
1
2
1
2
1
2
3
1
1
J
1
J
1
J
J
1
On
0
J
J
0
J
0
J
0
0
J
Off
90 minutes
60 minutes
30 minutes
120 minutes
Fan Delay
Shorting the jumpers for a period of 5 to 20 secs bypasses
the remaining continuous run period and places the unit in
a Forced Defrost mode. If the controlling DFT is closed
when this mode is initiated, the unit will complete a
normal defrost period that will terminate when the
controlling DFT opens or the 10 minute defrost cycle limit
is reached. If the controlling DFT is open when this mode
is initiated, the Defrost cycle will run for 30 secs. Both
modes end at the end of the Defrost cycle.
ELECTRIC HEATERS
50TCQ 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 Heater Section access
panel located just below the Blower access panel. Heater
modules slide into the compartment on tracks along the
bottom of the heater opening. See Figures 33 through 35.
Control Box
Access Panel
Filter Access
Panel
Blower
Access
Panel
Electric Heater Section
Access Panel
C09420
Fig. 33 -- Typical Access Panel Location
Not all available heater modules may be used in every
unit. Use only those heater modules that are ETL 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).
Main Control
Box
Filter
Area
Heater
Module
Indoor Blower
Access Panel
C10840
Fig. 34 -- Typical Component Location