Multiple Large Motor and Fan Projects
The fan unit was rebuilt with a full motor overhaul, winding Baker test, re-insulation and new bearings. The secondary fan drive shaft component had new bearings fitted, and the main support housing was machined and sleeved on the worn journals. The impeller was dynamically balanced, and the complete unit was rebuilt before all components were laser aligned. Both of these processes were carried out using high-quality CEMB Hofmann equipment. Upon assembly, the unit was run-tested, and all vibration levels were checked to ensure they were within acceptable tolerance limits.
The DC motor underwent a full degreasing cycle, and then all components were stoved to remove any residual moisture. The field, interpole and armature windings were fully Baker tested and re-impregnated with anti-tracking varnish. The armature was dynamically balanced, and new bearings were fitted. Both bearing housings were worn, so Webb Elec machined and sleeved them back to the correct size before assembly. The commutator was then machined, undercut and polished to remove all wear from the brush track and to ensure good commutation. Finally, the brushgear was overhauled with new carbon brushes fitted. The motor was then assembled, run-tested and painted.
The new 355kw AC motor was a special build from the manufacturer as it was a 6-pole 1000rpm machine, that will be mounted vertically, shaft down, on top of a large press. This is part of an ongoing project for a machine upgrade.