4
Technical Information
Service Manual
Knowledge of the basic SI standard units for temperature, pressure, mass, density, energy.
Understanding of the basic theory of refrigeration systems including the functions of the main components in the system (compressor,
evaporator, condenser, thermostatic expansion valves).
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The determination of non condensable gases in the refrigeration system and how to eliminate them.
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The elimination of humidity from the refrigeration system and how to recover or vent HC refrigerant from a system.
Usage of tables and diagrams (log p/h diagram, saturation tables of a refrigerant, diagram of a single compression refrigeration cycle)
and interpretation of these tables and diagrams.
Knowledge of the basic operation of the following components in a refrigeration system and their role and importance for refrigerant
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Carry out a pressure and leak test to check the strength and the tightness of the system.
Usage of a vacuum pump.
Evacuation of the system to remove air and moisture according to standard practice.
Knowledge of potential leakage points of refrigeration, air-conditioning and heat pump equipment. Making a visual and manual
inspection of the whole system.
Carry out a check for leakage of the system using an indirect method and/or one of the direct methods.
Direct leak detection methods:
1. Fixed leakage detection systems
2. Portable electronic gas detectors
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4. Weak soapy water solution (bubble test) also in combination with OFDN
5. New installation tightness test for leakage detection procedure e.g. H2/N2
6. Operational system tightness test for leakage detection procedure
Indirect refrigerant detection methods:
1. Visual
2. Manual checks
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Temperature and pressure controls
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Sight class and moisture indicators
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Defrost controls, reverse cycle operation
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System protectors
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Measuring devices such as the pressure gauge manifold
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Thermometer
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Leak detector
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Refrigerant charging devices
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Vacuum pump
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Oxygen free dry nitrogen cylinder and pressure regulator
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Electrical circuit assessment and repair
Basics in RAC
Checks before putting in operation, after a long period of
nonuse, after maintenance or repair intervention or during
operation.
Checks for Leakage
Read More!
SAFETY CODE
OF PRACTICE
FOR REFRIGE-
RATING SYS-
TEMS
UTILISING A2 &
A3 REFRIGE-
RANTS
ISBN
1 872719 15 5
