Pneumatics & Brake System Flashcards
What is Main Reservoir operating pressure? +-20
850-1000kPa
What is Emergency BC pressure?
280-460kPa
What is Maximum BC Pressure
250-380kPa
What is Holding BC Pressure
140-240kPa
What is Main Reservoir safety valve pressure?
1050kPa
What is Main Reservoir Safety Loop activation pressure?
600kPa
What is the ASU?
Air Supply Unit
Air Supply Unit Equipment Case
(not required to be inspected)
What does the ASU consist of?
Main air compressor
Air Dryers
Filters
Backup Compressor Governor
How many air compressors does a 7 car HCMT have?
Two
One in each Tc car
What does the Auxiliary Compressor do?
Raises pantographs when:
There is insufficient MR pressure
When car has been isolated from MR
Where is Auxiliary Compressor located?
DMp cars
If pantograph isolating cock is isolated on DMp car the pantograph will not be isolated. they will remain raised in the absence of MR air
Pg. 13
What Air Reservoirs are there on a HCMT
Main Reservoirs
Surge Reservoirs - supplies air to airbag, one for every air bag
Brake Supply reservoirs
What does the Brake Supply Reservoir do?
Supplies compressed air to the EP valves in the BCM to charge the BCs
How can pantographs be raised? (2)
MR pressure above 700kPa
Battery operatedAuxiliary compressor when insufficient MR pressure
How many pantograph ICs are there on DMp and Mp cars?
Saloon
and
Underframe
Which will isolate the pantograph on a DMp car?
Saloon
How can you reset the Trip?
Trip Reset switch on OJT panel
Trip rest plunger on the front of the trip
How do you isolate the Trip?
Turn Trip IC on B side between doors 2 and 4 on Tc car
and
Turn Trip Bypass switch in drivers cab to isolate
If you isolate the Trip what comes into play?
Safety System Bypass Acknowledgement button
What is the Post trip Speed Restriction?
Activates automatically after Trip has been activated.
restricts speed of train to 25kmh
Assists drivers to comply with extreme caution rule
How long does the Post Trip Speed Restriction apply?
500 seconds
How do you cancel Post Trip Speed Restriction?
Press Trip Speed button (under tamper cover) when relevant safe working conditions have been complied with
What are the ICs in the BCM?
Brake Supply
BC End 2
BC End 1
Tread Scrubber (Tc only)
Park Brake (not Tc)
Sanders
Where is the sanding equipment located?
Where are Tread Scrubbers located?
Wheel 3 and 4 on Tc cars
What do the Tread Scrubbers do?
Clean debris from wheel face to ensure proper conductivity of the track circuit
What type of brakes does each car have?
Out of holding, emergency, parking, ED and EP
Where is the BCU?
Inside the BCM
What does the BCU do?
Controls the application and release of EP friction braking
Where is the TCU?
Inside the VVVF Cabinet
What does the TCU do?
Controls application of traction power and ED braking
In emergency, what braking is used?
BCU takes over and friction EP braking only
How does friction braking work?
Main Res. air
via BCM to
Brake Supply Reservoir
back through BCM to
BCs - compressed air pushes brake pads onto discs
What ICs can isolate EP Friction brakes? (3)
Saloon Brake Supply IC (B06, door 4, every car)
BCM - BC ICs (one per bogie)
BCM - Brake Supply IC (one per car)
What is the Holding Brake speed threshold?
0.5kmh
When will emergency brake apply? (9)
How do you reset safety loop?
Train stationary for more than 3 seconds
Reason for emergency brake application reset
MCH to MAX BRAKE
Reverser to NEUTRAL
Where are the two Park Brake Isolating cocks?
Saloon - cabinet B07 near door 3
BCM IC
