Electronic Temperature Controls Sequence Of Operation - True TMC-49-HC Installation Manual

TRUE
milk coolers
LAE ELECTRONIC TEMPERATURE CONTROLS
LAE ELECTRONIC CONTROL GENERAL SEQUENCE OF OPERATION
1. Cabinet is plugged in.
a. Display will illuminate.
b. Interior light will illuminate on Glass Door Models only. Solid door cabinet lights are controlled by the door switch.
2. After the LAE control preprogrammed time delay of up to 6 minutes, the compressor and evaporator fan(s) will start if the
control is calling for cooling.
a. Control or condenser fans may be already pre-programmed from the factory so at the start of every compressor cycle or
during a defrost cycle, the condenser fan(s) will reverse for 30 seconds to blow dirt off the condensing coil.
3. The LAE control will cycle the compressor but may also cycle evaporator fan(s) on and off determined by the Set-Point and
Differential temperatures.
a. The Set-Point is the adjustable preprogrammed temperature which shuts off the compressor and evaporator fan(s).
This is not the programmed cabinet temperature.
b. The Differential is the non adjustable preprogrammed temperature that is added to the Set-Point temperature that will
restart the compressor and evaporator fan(s).
c. The LAE control is designed to read and display a cabinet temperature not a product temperature.
This cabinet temperature may reflect the refrigeration cycle of the Set-Point and its Differential, or it may show an average
temperature.
The most accurate temperature on a cabinets operation is to verify the product temperature.
The compressor and evaporator fan(s) will cycle off -9°F/-23°C and back on at 1°F/-18°C
4. The LAE control may be preprogrammed to initiate defrost by interval or at specific times of day.
a. At this time the "dEF" will appear on the display and compressor will turn off until a preprogrammed temperature or duration is
reached. During this time for freezers only, evaporator fan(s) will also turn off and the coil heater and drain tube heaters will also
be energized. Some cabinets may also change the rotation of the reversing condenser fan motor.
b. After the preprogrammed temperature or duration for defrost has been reached there may be a short delay for both the
compressor and evaporator fans to restart. At this time "dEF" may still appear on the display for a short time.
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Example: If the Set-Point is -9°F/-23°C and the Differential is 10°F/5°C
(Set-Point) -9°F + 10 (Differential) = 1°F
(Set-Point) -23°C + 5 (Differential) = -18°C
Or
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