We have diesel generators of 1750kW capacity. They are 16 cylinder V type engine coupled to a generator for emergency power source.Starting of the engine is done by an air motor, which cranks the engine initially for about 4-5 seconds (with a maximum of 8 seconds) after which engine picks up speed on its own. Recently we faced a problem that the air motor which was in service for the past 3 months failed to crank the engine. We replaced the air motor after confirming air pressure was adequately existing for the normal cranking. The second motor successfully cranked the engine. though the problem is solved, being an emergency equipment, we don't want a repeat of this failure. how to confirm that engine is not taking higher torque for cranking. what periodic checks can reveal problems with the engine / air motor. would any one help me. Lot of luv and thanks

Jayravi
We have a very similar DG at our facility with same emergency starting requirements.
We also experienced problems in the past with the air start motors, solenoids,etc.
Rather than go into details on this post, contact me on my email to discuss
Regards
Jim Powers ivibr8@yahoo.com