Reduced new and repeat traction inverter repair rates
Routine analysis by SET of its repair database indicated an emerging problem with increasing rates of both new and repeat repair operations on
The Challenges for SET
- Further analysis of data implicated the gate drive card.
- Extensive investigation of units with intermittent faults revealed micro-cracking of joints around a Zener diode - only visible under magnifi cation.
- Cracking was caused by thermal cycling of the device (heats each time vehicle accelerates) resulting in cyclic stresses in the solder joints and ultimately fatigue fracturing
- causing intermittent electrical connection
- SET designed and manufactured a turning rig.
- SET specified and had produced a set of customised packing cases that ensured that equipment arrived at the depot the correct way up for