In some facilities, every repair includes a system check. In other facilities, the repair consists of replacing whatever broke and doing system checks only during scheduled PMs. Which repair philosophy results in higher efficiency?
Suppose the drive motor of a big conveyor system burns up. Taking the time to perform a system check seems wasteful, since you can plainly see the motor is what failed. But things are not always as they seem.
Motors are typically part of a larger system (such as the aforementioned conveyor system). Replacing the motor fixes the symptom (failed motor) but not the problem. The problem could be voltage imbalance, which is an electrical issue.
But what if it’s a mechanical issue, such as the gearbox is low on oil or that oil is overdue for a change? Since nobody saw a mechanical problem but did see an electrical problem, the mechanics were not called to check their part of the system.
So the electricians replaced the motor, which then drives a high-friction gearbox (something that can be verified using thermography). The motor must draw more current to do the same work, which means the motor runs hotter. Heat shortens motor life.
