Variable Speed Drive Enclosures

Rolla have been designing and supplying enclosures for Variable Speed Drives and Soft Start Units for many years. Some of the special features to be taken into account include :-

- ventilation

- internal segregation

- interlocking between multiple access doors

- interconnections between devices

- EMC requirements

The pictures below show some of the recent jobs we have completed. All the small wiring is carried out by our panel builder customers, we provide the supporting structure and solid busbar connections.

250KW unit using ABB ACS800 series modular drive, under construction.

Drive modules in place, can be removed from the front for maintenance.

Outer view of a suite of drives, air inlet ventilation cutouts at the bottom of the doors.

Air inlet vents and outlet fan cutouts on the doors. This is a popular arrangement, but care must be taken with the room ventilation due to heat from all the drives.

Curved drive suite we did for the ODA pumping station in London. This suite had to fit around the internal curve of the building.

This drive is complete and ready for test. Note internal baffling to prevent air recirculation within the enclosure.

1250KW drive, one of 6 for the new St. Germans Pumping Station near Kings Lynn.

View with the doors open. All the doors are interlocked mechanically so they cannot be opened until the drive is isolated.

AC and DC busbars, with high speed fuses.

DC link bars (normally operating at about 700V DC) and special chokes. This is the output stage of a triple module drive.

Complete drive, ready for test.

Small soft start unit (Rockwell/Allan Bradley). Wiring not yet complete.

Large soft start unit.