Bad maintenance practices tend to sneak into the way things get done. This article includes three more to guard against.
Bad Practice #17 — Testing and Maintaining Components, but Not the System.
A hospital properly tested its back-up power components (transfer switch, UPS, back-up generator), but nobody tested the system. During an outage, the hospital went dark. The transfer switch had not been connected to the UPS — something that system testing would have revealed.
Bad Practice #18 — Not Running the Back-up Power System for PM Purposes.
Static testing of the system is good, but you need to actually run it. One thing you can do while it’s running is use infrared to properly check for degraded electrical connection.
Bad Practice #19 — Load Testing Batteries Annually.
Load testing intuitively makes sense. You run your UPS to see how long it can support the load. But the deep cycling means this is costly in terms of battery life. Also, there’s much it does not tell you, and it has other downsides. Instead, use internal resistance testing to determine the health of individual cells.