INTRODUCTION TO THE JOB
Atlas Cove Depot is a major PPMC depot through which imported petroleum products are received and pumped to Mosimi depot for distribution to other parts of the country. The four installed 2750kVA EMD generators are the major source of electric power to the depot since PHCN power supply is still not extended to the island. There is need to keep these generators in good condition at all times to guard against catastrophe of fuel scarcity. At present, one of the engines that had crankshaft damage is being repaired and overhauled; an alternator will be needed to run the set. The practice of swapping alternator is being avoided as this can cause misalignment and further engine or alternator failure.
We target complete availability of all the four alternators and the two spare alternators for use in emergency. In line with this target, a faulty alternator was identified and observed for rehabilitation. Pictures of the damages are attached
Steps in repair and rewinding of the alternator.
Pull apart: this is involves practically disengaging the alternator from the panel. 12 long bolts tightly held the alternator which we had to unscrew gently in order not to damage the bolts. 1.After this the alternator was gently removed and placed on the working surface which is usually on the ground. The alternator is then uncoupled. Then we removed the field connection brushes from the rear of the case, it had the letters F and N on the connector, being field and neutral. Once everything was apart, we checked the bearings for wear, they should turn freely without noise of grinding, and they shouldn't spin which would indicate that they are dry. 2.The wiring varnish/shellac had sharp edges, so we were careful when removing the old windings. The original windings were 13 turns of 1.2mm diameter and we reduced the wire diameter to 0.75mm in order to double up on the...