GB
2.4.4
Refrigerant circuit functional principle
Item
Designation
1
Compressor
3
Expansion valve
5
Condenser fan (external)
7
Electronic control with temperature sensor
The cooling units are comprised of various components; see the figure Refrigerant circuit.
The compressor (1) compresses the refrigerant under high pressure. The temperature increases.
This heat is released to the ambient air in the condenser (2). The refrigerant liquefies.
The condenser fan (5) draws room air through the condenser (2) and releases it to the environment.
A pressure drop occurs when the refrigerant passes through the expansion valve (3).
Inside the evaporator (4), the refrigerant absorbs heat from the air inside the switch cabinet and evaporates.
The air inside the switch cabinet is cooled and dehumidified.
The evaporator fan (internal) (6) draws the air inside the switch cabinet through the evaporator (4) and releases
the cooled air back to the switch cabinet.
The cooling units are controlled with a temperature sensor (7). It detects the air temperature inside the switch
cabinet.
Operating Manual DTS and DTI 6201C / 6301C Standard Controller (SC) 086100015 © Pfannenberg GmbH
5
3
2
1
Figure 5 - Refrigerant circuit
Item
2
4
6
6
4
7
Designation
Condenser
Evaporator
Evaporator fan (internal)
Page 9 / 38