5
V. Principles of Operation
Kooltronic Air Conditioners are required when the equipment operating temperature
must be kept near or lower than the ambient room temperature, and/or the cabinet
must be sealed from dust, fumes, oil, corrosives and other contaminants. These Air
Conditioners utilize a "Closed-Loop Cooling System" to ensure optimum performance
of the installed components.
Closed-Loop cooling seals the electronic enclosure from hostile elements in the
environment. Two separate circulation systems are employed. The internal system
cools and dehumidifies the air inside the cabinet, totally isolating the sensitive
electronics and other components from the environment. The external system
uses circulating ambient air or water to discharge the heat removed from the
electronics. The heat is dissipated from the enclosure by means of the vapor
compression refrigeration cycle. This takes place in a hermetically-sealed
refrigeration system, utilizing either an air-cooled or water-cooled condenser heat
exchanger. The warm air inside the enclosure is drawn through the evaporator coil
where it is cooled, dehumidified and returned.
Any enclosure moisture accumulated on the evaporator coil is collected in the condensate tray and removed through
the drain tube to the condensate evaporator. Condensate evaporates in the condensate evaporator and is released to
the ambient air by the condenser impeller.
The heat removed through the evaporator coil is transferred by the compressed refrigerant to the condenser coil. Ambient
air is then passed through the condenser coil, where it absorbs the heat and is then discharged to the environment.
When the Kooltronic Air Conditioner is properly sized it should operate constantly and maintain 75°F to 115°F enclosure
temperature, depending on the ambient temperatures.
CONTROL ACTION
The evaporator blower operates continuously. The compressor is cycled on and off by the action from the factory preset
programmable thermostat. A pressure switch controls the on/off action of the condenser blower.
The regulation is performed according to the temperature measured by the thermostat probe with a positive differential from the
set point: if the temperature increases and reaches set point plus differential the
compressor is started and then turned off when the temperature reaches the
set point value again.
In case of fault in the thermostat probe the start and stop of the compressor
are timed through preset parameters.
The programmable thermostat is located as shown in the upper right ISO
illustration. WARNING: the programmable device is preprogrammed and set
at the factory. In the event changes are needed the following instructions can
be used.
FRONT PANEL COMMANDS
FRONT PANEL LED INDICATORS
- To display target set point; in programming mode it selects a parameter or confirms an operation.
(UP)
- To see the max. stored temperature; in programming mode it browses the parameter codes or increases the displayed value.
(DOWN)
- To see the min. stored temperature; in programming mode it browses the parameter codes or decreases the displayed value.
- To switch the instrument off, if onF = oFF.
- Not enabled.
(DEF)
- To start a manual defrost.
KEY COMBINATIONS
To lock and unlock the keyboard.
To return to the room temperature display.
To enter programming mode.
EVAPORATOR
AIR OUTLET
EVAPORATOR
AIR INLET
CONDENSER
AIR INLET
CONDENSER
AIR OUTLET
DSP23L
