Your company recently changed electrical testing firms. The new firm, which is NETA-certified, came highly recommended. However, the plant manager is puzzled by the firm's report. They identified nearly 30 breakers that need repair of some sort. "Yet," the plant manager says, gesturing around the room, "the lights stay on just fine."

The testing firm also submitted a list of recommended tests that haven't previously been done at your plant. These include transformer oil analysis, testing of the power factor correction capacitors, and a recommended program of cable testing.

The plant manager wants you to confirm or deny the firm's findings. Where do you start?

First, you need to understand what testing your company should be doing in general. To get that understanding, you must know what testing standards apply to your facility and its electrical infrastructure. Since your company is paying for these tests, purchase your own copies of the standards.

At a minimum, you should have these two sources on hand:

  1. ANSI/NETA Standard for Maintenance Testing Specifications.
  2. IEEE STD 242, "Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems," otherwise known as the IEEE Buff Book
Next, compare the testing proposed by the new firm, the testing done by the old firm, and the testing recommended in the standards. Determining what the previous firm did incorrectly (or not at all) will answer your plant manager's concerns. Resolve any differences between the standards and what the new firm is proposing. This will help you implement a future testing plan.