Pneumatics Flashcards
What equipment runs on compressed air? (7)
Main Reservoirs
Auxiliary Reservoirs
Air Suspension Reservoirs
Surge Reservoirs
Whistle
Friction brakes
Spring Park brake
What pressure does the Compressor Governor / Compressor Pressure Switch maintain the Main Reservoir at?
850 - 1000 kPa
What pressure are the Safety Valves set at?
1100 kPa - between compressor and air dryers
1050 kPa - between air dryers and Main Res.
What happens if the Compressor Pressure Switch (CG) is isolated?
The air compressor will run continuously
What is the air suspension system made up of? (3)
Levelling valves
Air bags
Surge reservoirs
What do the Levelling Valves do?
They Inflate or deflate air bags according to passenger load
On DM Cars: One on each bogie.
On T Cars: Two on No.1 Bogie, 1 on No.2 Bogie
What happens if air bags fail?
There is a spring system as well.
What do the Surge Reservoirs do?
Supply air to the air bags to compensate for:
Train tilting around corners
Uneven passenger load
Sudden imbalance in suspension system
Two surge res. per bogie
What is the Brake System comprised of?
Service Brake (Friction
Holding Brake
Emergency Brake
Park Brake
What is the Service Brake made up of?
ED
EP
When does the ED Brake work?
Normally, above 10kmh
Between 5-10kmh. brake blending occurs
What happens during wheel slide?
ED brake drops out and EP brake takes over
What is the EP brake used for?
Stopping at low speeds when ED brake fades out
Assisting ED brake during heavy high-speed braking
Supplementing braking demand when effort provided by the ED system is insufficient
What happens if ED brake fails?
EP brake will automatically take over
What kind of brakes are on TCars?
EP brakes only
When does the Holding Brake apply?
when MCH is in 0 (coast) when train is stationary.
What is Holding Brake pressure?
110 kPa (+/- 30 kPa)