Suppose a 10-hp motor fails. This doesn’t sound like a big deal. A 10-hp motor is relatively inexpensive. So you replace it. But suppose that motor is critical to a production bottleneck that produces $650,000/hr of revenue. Now that 10-hp motor failure sounds like a big deal.
Think about the cost of production loss so you know when to spend more time making sure the repair really solves the failure cause.
Let’s say this motor ran hot. As one astute EC&M reader pointed out, the cause can be surprising. He discovered that the wrong pulley was being used to drive the load. All sorts of mismatches can happen. And they aren’t always obvious. Walk through the whole system (input, motor, load) and check every item in the whole chain of energy flow.
Two examples:
• At the supply to the motor branch circuit, someone used one phase to power a bank of lights. This caused a voltage imbalance.
• A helper changed the oil in a motor gearbox, using oil of the wrong viscosity and failing to hit the full mark. Properly changing the oil corrected the heating problem.
