Previously, we addressed some items you should include in your breaker maintenance procedures. Now, we'll look at three more such items. These are typically mentioned together. The industry jargon for these is "check anchorage, alignment, and grounding."
What do these really mean?
- Anchorage. Typically, a breaker mounts to its enclosure (or draw-out rack) via several bolts. Check all fastening points.
- Alignment. This test procedure involves operating the breaker multiple times to ensure the secondary connectors properly engage. The actual testing doesn't take long, but setting it up could take considerable time due to load disconnecting requirements and necessary safety procedures.
- Grounding. Breakers in your facility are bonded, not grounded (see NEC Art. 100 definitions). At a minimum, visually inspect. To maximize reliability, test the bonding connections with an AC low-ohm meter.