You were recently hired as the new electrical maintenance manager. The plant engineer said the plant is apparently infested with gremlins, at least electrical ones.
“I’ve been here three years now, and though the mechanical failure rates have gone down except for bearing failures, the electrical failure rates have gone up. Overall downtime has gone up.”
It seems the electrical problems are wide-ranging. Among the issues the plant engineer discussed:
- Nuisance breaker trips.
- PLC power supplies have been replaced enough times to be noticed.
- Lights flicker, lighting levels seem to vary, and ballast failure rates are high.
- Motor failures have increased 25% over the past three years.
What would you recommend?
This “electrical gremlin effect” is a strong indication of systemic power quality problems. Many plants with such problems also seem to have a managerial opposition to installing a power monitoring system, which is why they can’t get a handle on what’s going on. So, you need to strongly recommend the installation of a power monitoring system that includes not only monitoring at the service but also at each load that you might classify as critical and/or major.
The trick here is you need a qualified individual to interpret what the monitor says so appropriate corrective action can be taken.
Next, look at surge protection; a staged system is a “must do” to get rid of the gremlins. Then examine equipment bonding per Art. 250, Part V of the National Electrical Code (NEC); eliminate differences of potential.
