11.4 Pressurisation Systems Safety & Warning Devices Flashcards
What are the three types of leak detectors in a vapour cycle air conditioning systems
Can use electric leak detectors which are extremely good at detecting leaks, using a soapy solution to create bubbles and injecting special leak detection dyes which are visible under UV light
What is particularly susceptible to leaking
Hoses
What type of refrigerant is no longer used due to ozone damage
R12
What type of refrigerant has been used since the 1980s
R134a
What pressure is low pressure refrigerant
0-150psi
What pressure is high pressure refrigerant
0-500psi
What is the most obvious way of detecting a leak in the vapour air cycle
Low refrigerant level
What temperature should air out of evaporator read in normal operation
4-10°C
What is purging the system
Releasing the refrigerant charge
How do you know refrigerant is contaminated
Bubbling of refrigerant
How do you check compressor oil level
Dipstick can show levels
What is used to depressurise vapour cycle air
A vacuum pump
What is a bleed air leak
Uncontrolled loss of bleed air from any part of pneumatic system
Where are failures shown to the pilot
Master warning light and voice warning message
