TRACTION ELECTRICALS · QUICK REFERENCE
MCB Resetting Procedure
Sometimes an MCB trips momentarily without any equipment failure. Identify the make fitted in your loco below and follow the matching reset steps.
Attempt reset only once. If the MCB trips again after resetting, do not repeat the attempt — report and proceed as per the relevant SR/GR instruction.
ABB make MCB
Resetting procedure
- Check the small reset screw below each of the three phases. During tripping it can turn from vertical to horizontal.
- If any screw is in the horizontal position, turn it clockwise with a screwdriver back to vertical — do this for all three phases before proceeding.
- Reset the MCB by lifting the handle upward. Lift the handles of all three phases together, at the same time.
Merlin Gerin (MG) make MCB
Resetting procedure
- Pull the handle downward first, fully to the OFF side.
- Then pull the handle upward, to the ON side, to complete the reset.
Schneider & other similar MCBs
Pick the type fitted on your loco
Handle type
- Pull the handle downward first, fully to the OFF side.
- Then pull the handle upward, to the ON side, to complete the reset.
Knob type
This type has two indicator knobs — red and black/blue — that show the trip state.
| State | Red knob | Black / Blue knob |
|---|---|---|
| Normal | OUT | IN |
| Tripped | IN | OUT |
Press the blue RESET button back in to clear the tripped state and restore normal position.
Rotating knob type
- Rotate the knob from the 9 o'clock position to the 12 o'clock position to reset the MCB.