Manual Part 7

Heat Exchanger Climate Unit
4.1 Heat Exchanger
The heat e xchanger consists of a cross-flow heat e xchanger and internal and
external air circuit fans.
Outside ( ambient) air is forced thro ugh one side of the heat exc hanger by
DC-powered fans. Onc e there it co ols the inside air, which circulates through
the other side of t he heat exchanger.
Ambient air is used on the ’cool’ side of the heat exchanger, and therefore
cooling capacity is limited to th e temper ature outside the cabinet. If the ambient
temperature is higher than the cabinet retu rn air temperature, then the external
air circulation fan stops to prevent th e outside air warming the cabinet.
4.2 Heater
The heater is placed in the internal air cir cuit and heats the air if the ambient
temperature is too low for startup.
The heater is powered by mains voltage, and heats the inside air if the startup
temperature inside the cabinet is below -5
C. The heater has a capacity of
2 kW.
The C CU measures th e return air temperature and con trols th e heater.
4.3 CCU
The Climate Control Unit (CCU) is a processo r-based plug-in unit, controlling
and supervising the climate unit. The CCU provides the following ma in
functions:
• Monitors internal and external temperatures
• Monitors and controls the internal a nd external fans
• Monitors and controls the heater
• Handles alarms
• Supervises Mains Voltage
• Tests the Heat Exchanger Climate Un it
Backplane and Front Panel
The backplane connector s contain the climate unit internal inte rfaces to the
following:
• DC power
5 (8)
EN/LZT 720 0311 Uen R2A