Faults - Comeng

Question 1

What must be checked before performing a ROBBDS test?

Answer 1

Trip - lowered and set
Switches - toggle switches, C/B in normal position and doors closed
Gauges - Mr, Bp and control Res in operating ranges
Cocks - BVICS open, red EC, yellow TECHAV normal

Question 2

What would indicate that the train has access to the 110vDC train lined power?

Answer 2

Supply light “on”
Door lights illuminated
LP flag lowered, EP operational
Bell button operates

Question 3

What does the ROBBDS test check?

Answer 3

Reverser
Overload reset (traction)
Bp reduction
Bypass (control gov)
Door loop bypass
Second controller

Question 4

What does the first step of the ROBBDS test check?

Answer 4

Tests the reverser:
-Place reverser in reverse, try for power
-If train powers, fault is in the reverser

If train does not power in reverse, move to next step

Question 5

What does the second step of the ROBBDS test check?

Answer 5

Overload reset button:
- press traction overload reset
- pull for power

If train powers, submit TMM
If no power, move to next step

Question 6

What does the third step of the ROBBDS test check?

Answer 6

If control governor is causing failure via Bp reduction

• Make Bp reduction below 325 kPa
• Restore Bp pressure (above 430, control Gov closes)
• try for power

If power obtained fault is with control gov opening/closing