When pumping down a refrigeration system it is recommended to leave _______ residual pressure in the system to prevent air being drawn in through minor leaks or compressor shaft seals.
a. 7 to 15 kPa abs
b. 5 to 15 kPa abs
c. 4 to 14 kPa abs
d. 7 to 14 kPa abs
e. 10 to 20 kPa abs
Answer: D
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Power Engineering Chapter 122
- Which of the following steps is not a step in the startup of a reciprocating or rotary compressor refrigerating system?
- When a chiller has stopped due to low water temperature, and the chilled water temperature subsequently rises approximately 5-6°C above the chilled water temperature set point, the:
- To avoid liquid slugging in a direct expansion evaporator after shutting down a reciprocating or rotary compressor refrigerating system which of the following measures needs to be taken?
- If a refrigeration compressor fails to start but the motor is running, which of the following could be a cause?
- A system of regularly scheduled inspections and lubrications along with the adjustments, minor parts replacement and minor repairs necessary to keep the refrigerating plant and equipment in good operating condition is defined as what:
- Which of the following steps is not part of the start-up procedure of a centrifugal compressor refrigerating system?
- A safety control designed to protect the chiller from freezing is the:
- An entire centrifugal compressor refrigerating system, including the auxiliary equipment, can be stopped by simply pressing a stop button, unless
- Electrical starters and contractors should be inspected
- The safety control of a centrifugal compressor, that ensures the compressor only starts under a no-load condition is called the
- Over charging the system with refrigerant will create:
- Which of the following steps is not part of a start-up of a reciprocating or rotary compressor refrigerating system?
- When some refrigeration systems are to be shut down for a prolonged period of time they should be "pumped down" and the refrigerant stored in the:
- If the chilled water temperature drops approximately 2.5-3°C below the chilled water temperature set point, the chilled water low temperature cut out will:
- The chilled water flow switch prevents the: