The brief
The store had been extended twice, and its wiring had grown with it: motors fed from different boards, isolators that were not dust-rated, and no clear interlocks between the dryer, elevator and conveyors. The client's DSEAR assessment classified the inside of the silos as Zone 20, the elevator head and silo tops as Zone 22, and the intake pit as Zone 21. The work had to be finished before the store filled.
What we did
- Panel build: a new MCC with starters, interlocks and level controls for the dryer, elevator and conveyors, built and tested in our panel shop over the summer.
- Dust-zone installation: Ex t rated isolators, junction boxes and lighting in the classified zones, with cable entries and glands to suit, installed by CompEx certified electricians.
- Re-feeding the plant: every motor re-fed from the new MCC, with emergency stops along the conveyor run.
- Testing and inspection: testing to BS 7671 and an initial Ex inspection of the dust-zone equipment, with records in the client's portal.
The result
The store went into harvest with one MCC controlling the whole process, interlocks that stop the line in the right order, and equipment rated for the zones it sits in. The client has the inspection records and the next due dates in their portal.
