Two months ago, you hired on at this factory as the electrical maintenance engineer. Today, a production area shut down due to a feeder cable fault. Several electricians told you this happens every couple of months. You see a career opportunity in getting the plant off this Merry Go Round. There’s no power monitor. Where do you start?
Start by requisitioning a power monitor. Then discuss with the plant manager how an insulation resistance testing program can stop these faults and that you want to outsource it to a qualified testing firm. Be sure to point out that the plant has been very lucky thus far that no fault has been catastrophic but the luck will eventually run out.
Conductor insulation age is probably a factor, but transients could be taking out those cables. So carefully analyze the plant’s surge protection system, if it has one, noting that these systems need to consist of multiple, energy level specific layers. Also look for bonding deficiencies, large motors starting across the line, and rodent/pest issues.