Siemens Pneumatics

Question 1

What is the normal operating pressure of the MR?

Answer 1

850-1000kPa

Question 2

At what pressure will the air compressor start?

Answer 2

850kpa

Question 3

What are the 2 safety valve settings?

Answer 3

1100kpa b/w compressor and air dryer
1050kpa b/w air dryer and main res

Question 4

What systems use compressed air?
(5 answers)

Answer 4

EP brake
Park brake
Whistle
Air suspension
Sanding equipment

Question 5

What do the auxiliary reservoirs provide air to?

Answer 5

Pneumatic braking system

Question 6

What is the function of the levelling valves?

Answer 6

Inflates or deflates air bags according to passenger loading

Question 7

What is the function of the air bags?

Answer 7

Compensates for passenger loading and maintain a constant floor height (pax comfort)
Spring suspension as backup.

Question 8

What is the function of the surge reservoirs?

Answer 8

Supply air directly to the airbags to compensate for:
Train tilting around a curve
Uneven pax loading
Sudden imbalances in air suspension system

Question 9

What is the function of the air suspension reservoir?

Answer 9

Supplies air to the air suspension system

Question 10

What brake systems does a Siemens have? (4 answers)

Answer 10

Service brake
Holding brake (110kpa)
Emergency brake (280kpa)
Park brake

Question 11

In normal operation, what speed does the ED brake apply?

Answer 11

10km/h and above
(Faded out below 10km/h)

Question 12

When does the EP brake apply?

Answer 12

Usually below 10km/h
Depends on load and speed of train, used during wheelslide events (ED gets cut out)
Always used on trailers.

Question 13

What will happen to the ED brake during wheel slide?
How will you know this has happened?

Answer 13

ED brake cut out for rest of braking application
Electric brake inhibit button will light up.

Question 14

What is the holding brake pressure and when does it apply?

Answer 14

110kpa
Applies when Master Controller handle in coast and train is stationary

Question 15

What is emergency brake cylinder pressure?

Answer 15

280kPa

Question 16

When does the emergency brake apply?

Answer 16

When the safety loop is de-energised

Question 17

Mechanically, how does the spring brake work?

Answer 17

Spring applied
Main res air released

Question 18

When does the spring park brake apply?
(2 answers)

Answer 18

Master key turned to off
Main res pressure below 350kPa

Question 19

Where are the park brakes fitted?

Answer 19

Wheel 3 & 7 all cars

Question 20

How do you manually release the spring park brakes?

Answer 20

Isolate the bogie and pull the park brake manual release handle. Reinstate the bogie.

Question 21

What will happen if you apply the spring park brake over 5km/h?

Answer 21

Safety loop de-energises, emergency brake applies.

Question 22

What is the function of the BCU?

Answer 22

Processes the input to apply and release the brakes. Automatically adjusts to determine EP/ED braking requirements.

Question 23

What isolating cocks are in the brake module?

Answer 23

Air Suspension isolating cock
Bogie isolating cock

Question 24

Is wheel slide protection available in all braking modes?

Answer 24

Yes

Question 25

When do the sanders operate?

Answer 25

When the BCU senses wheel slip during EP braking. Not during ED braking or powering.