The closing of your plant ended your job as the plant electrical engineer. But on the recommendation of a friend, you’ve just been hired through a temp agency to serve as another plant’s interim plant engineer while they conduct a search. A clause in the contract allows the company to hire you for that position after 90 days with the agency, and you really want the job.
It just so happens this plant has been plagued by nuisance breaker trips. The previous plant engineer had flailed away at this problem, but didn’t devote much time to it because motor failures were consuming the time he could devote to electrical issues. What strategy might you take to nail both problems?
The two problems are likely related. A good strategy would involve looking for root causes. For example:
- Pick a feeder that’s had both problems. Conduct an inspection for bonding deficiencies, use a power analyzer to look for power anomalies, and identify any large motors that start across the line.
- Measure power factor at each large inductive load, and correct at the load as needed.
- Examine the transient protection scheme. Remember that transients from outside the plant are less of a concern than those generated inside the plant. So, the transient protection needs to be built into the power distribution system in a way that protects individual circuits from large load-generated transients.