TM 9-4120-411-14
2.4.1.8 Choose which control panel, integral to the unit or remote, will be used then position the CONTROL SELECTION
switch (10) to either THIS PANEL or REMOTE BOX as applicable. If the remote control box is to be used, and was not
installed, notify unit maintenance for installation.
WARNING
Rotating parts are used in operating the FDECU. Do not install or adjust return air
duct when inside blower is operating. The flange assembly can disengage and
come off resulting in personal injury.
NOTE
Fresh outside make-up air is recommended during normal operating conditions.
2.4.2 Vent Mode. Push the VENT MODE ON/OFF momentary push button switch (11) to activate the inside blower. The
ON indicator light (12) will illuminate. This will only circulate the shelter air and will not control the temperature. Check
that the duct (1), connected to the FDECU return air flange assembly (2), was installed back on the flange assembly far
enough to expose the perforated holes as necessary. To assure a continuous supply of fresh make-up air, at least four or
five rows of perforated holes should be exposed.
2.4.3 Climate Control (Heating/Air Conditioning). Set the TEMPERATURE knob (13) slightly right of the control range
mid-point, or 1:00 position. This is approximately 75 F. Push the CLIMATE CONTROL ON/OFF momentary push button
switch (14) to activate the automatic temperature control system. The ON indicator light (15) will illuminate. Note that a
control logic time-out circuit may prevent the unit from operating immediately. If this occurs, do not turn the unit off, it
should start automatically within 5 minutes. (FDECU-2 ONLY) Note that if the COMPRESSOR WARM UP indicator light
(16) is illuminated, the compressor is still warming and will not operate, however, the unit will operate in vent or resistance
heat mode. When the system is fully operating, the TEMPERATURE knob can be rotated to increase (clockwise) or
decrease (counterclockwise) the shelter air temperature within a range of 60 F to 100 F and will maintain the
temperature to within 5 F of the setting. If the unit is operating in the cooling mode, do not adjust the TEMPERATURE
knob from the 1:00 position for several hours after starting the unit, this will give the shelter air temperature time to
stabilize. The inside coil may begin to ice over in moderate ambient temperatures if the TEMPERATURE knob is adjusted
to the lowest setting, fully counterclockwise. If the inside coil does begin to ice over, operate the unit in vent mode for
between 5 and 10 minutes. This will de-ice the coil. If the inside coil becomes severely iced over, turn the
TEMPERATURE knob clockwise to activate the heating mode for between 10 and 15 minutes. Observe the drain hose
and note the condensate flow. As the coil de-ices, the flow of condensate should initially increase then decrease when
the coil is clear of ice. When the coil has de-iced, adjust the TEMPERATURE knob back to the 1:00 position.
2.4.4 Shutdown.
2.4.4.1 If operating in climate control (heating/air conditioning), push the CLIMATE CONTROL ON/OFF momentary push
button switch (14) to de-activate the automatic temperature control system. The ON indicator light (15) will go out.
(FDECU-2 ONLY) To
avoid compressor warm-up time delay, power must stay connected to
the unit when shut down to
maintain the compressor temperature above the surrounding ambient air temperature. On some FDECU-2 units, the
compressor crankcase sensor has been bypassed to eliminate the compressor warm up delay.
2.4.4.2 If operating in vent mode, push the VENT MODE ON/OFF momentary push button switch (11) to de-activate the
inside blower. The ON indicator light (12) will go out.
2.4.4.3 Unclip quick release pin (8) then close the fan cover door (7) and secure with fasteners.
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