Train Electrics Flashcards
What are the High Voltage Circuit equipment? (7)
Pantograph
Lightening arrestor
HSCBs
Line inductors
Traction inverter
Brake resistor grids
Auxiliary inverter (SIV)
What does the Lightening Arrestor do?
Protects 1500vDC against transient over voltage
What do the HSCBs do?
Another layer of protection. They will trip if there is a short circuit in train or overhead
What does the Line Inductor do?
Filters overhead power
What power do traction motors operate on?
3 phase variable AC
What does the TCU do?
Acquires information (speed, weight, commands and determines the appropriate amount of power or ED brake
What makes up the Low Voltage System? (6)
Auxiliary/Static Inverter (high and low)
400/220 AC
110 DC
24 AC/DC
Batteries
Air Conditioning system
What do Static Inverters (SIVs) do?
Convert 1500vDC into 400vAC
Supplies power to Auxiliary Equipment
What do the SIVs supply power to?
Battery Charger
Air Compressors
Traction converter cooling fans
HVAC
GPOs (220vAC)
What happens if one Static Inverter shuts down?
The other one will supply essential electrical equipment:
- Battery charger
- No.1 air compressor
- Both traction converter cooling fans
- No.1 AC in each car
- Full saloon lighting
What does the Battery Charger do?
What voltage does it produce?
Runs 110v equipment
Keeps batteries charged
Produces 110vDC to a maximum of 123.6vDC
What are the 3 110vDC distribution lines corresponding to different operational state of the train?
Permanent Low Voltage Line
Prepared Low Voltage Line
Prepared Low Voltage and Cab Operative Line
What is the purpose of the Permanent Low Voltage Line?
What does it power?
To raise the Pantograph’s
It powers:
- Pantograph electric motor
- Step lights
- Fluorescent cab light
What is powered on the …
Prepared Low voltage and Cab Operative Line?
Basically … everything
Panto, Status fault indicators, traction control, braking control, door control, safety loop, communications, lighting …
What is powered on the …
Prepared Low Voltage Line?
This is when the key is removed and the train enters a service retention mode:
- Pantograph’s remain raised
- Settings of the last active cab are memorised
- Marker lights, doors and saloon lights retain the setting they had when key was removed
… changing ends …
Where does the 24vDC power come from?
It’s derived from the Prepared Low Voltage line
What operates on 24vDC?
Headlights, driver’s seat, marker lights, speedo, windscreen wipers, gauge lights, MAD button CCTV, brake lights …
What is powered by 24vAC?
High beam headlights
CCTV cameras
How does the Permanent Low Voltage line remain energised when the train is stabled?
Batteries
In normal operation, what charges the 110vDC equipment?
The Battery Charger
If a Static Inverter fails or there is a loss of high voltage how does emergency equipment get its power?
Batteries
How long will the batteries work for?
1 hour … to get the train off the mainline
What is the Safety Loop?
Electrical circuit that connects all of the safety critical components to the Emergency Brake System
What will activate the emergency brakes? (10)
Main Res. falls below 580 kPa
BP falls below 300 kPa
Trip is activated or raised
Hand or Foot vigilance devices not set
Activation of VICERS
Loss of 110vDC
MCH placed to emergency
Emergency stop button pressed in any cab
Two or more controller keys inserted
23Q1 or 23Q2 CBs trip in lead cab
How do you reset the Trip?
Speed must be below 0.5kmh
Train must be stationary for 5 seconds
Turn Trip Cock Device to RESET and release
Trip activated light will extinguish when reset
What does the Safety Loop Test look for?
It tests to see if 23Q1 or 23Q2 CBs have tripped. They protect the Safety Loop
What do you have to do while doing the Safety Loop Test?
Set the Hand Pilot Valve
If you use the Safety Loop Switch (put it in BYPASS) what does this mean for the train?
There are no emergency brakes
What positions does the 110v Safety Loop Supply Switch have?
NORMAL
RESCUE
Don’t confuse with Safety Loop Bypass switch - Normal, Test, Bypass
What is the 110v Safety Loop Supply Switch for?
After failure of 110vDC power and being rescued by another XTrap, turn to RESCUE.
Allows power from rescuing train to energise Safety Loop
When a saloon door is released, then opened … how long will it remain open?
1 minute
If the master key is withdrawn from the key switch, how long will doors 1,2, 5 & 6 remain open for?
10 minutes
If the doors are obstructed how many times will they attempt to close again?
In total 4 times at 3 second intervals
The first time they will fully open
Subsequent times they will close against the obstruction, then release
Finally, they will remain touching the obstruction but remain released
A beeping tone will sound for 60 seconds
What do you have to do if doors failed to close?
Release doors, and try again
What does the Door Loop bypass key switch allow?
In the event of FDCL, setting to Bypass allows traction so the train can be moved.
Can you turn the Door Loop Bypass key back to the normal position?
No. Only maintenance staff
Where are the external Emergency Door Release?
Doors 2 and 5 of all cars
Doors 1 & 6 of Mc’s
What is the normal position of the lug?
Horizontal
Where are the internal Door Emergency Release handles located?
Doors 2 & 5
What happens when the DER is activated? (6)
FDLC
Door can be manually opened or closed
Traction power available until train stops
CCTV camera activates near DER handle
ANSW red button on drivers console will flash
The DOOR EMY HANDLE ACTIVATED status light will illuminate
How do the communication doors open and close?
Manually opened
Automatically closed
When does emergency lighting become operative?
If Battery Charger fails for longer than 1 minute
What positions does the Saloon Lighting switch have?
1 - Normal - full lighting on both sides
1/2 - Reduced to emergency lighting on one side of the car and normal on the other side
0 - Emergency lighting - one light above each door
How can you reset the timing cycle on VICERS?
Whistle
MCH
Acknowledge Button
How long will the VICERS light flash for?
5 seconds
How long will warning tone sound for?
5 seconds
If the VAV is activated how do you reset VICERS?
Bring train to stand for 10 seconds
MCH to Coast
Observe Emergency Brake Applied light illuminated
Push VICERS acknowledge button
What state does the train have to be in to test VICERS?
Vigilance key switch in OPERATE position
Cab activated
Trip lowered and set
Train @ 0kmh
Hand or foot pilot valve set
Emergency Brake Released
If Safety Loop or any Auto Vigilance systems have been bypassed, what should you do to VICERS?
Set VICERS key switch to ISOLATE to reduce distraction
Where are the Speed Sensor cables located?
Wheels 4 & 8 on Tp
Which cable is the Speed Sensor cable?
T for TACHO
T for Top cable
