Description
Product Introduction
REF542 is ABB’s compact digital bay control and protection unit for medium-voltage switchgear automation, combining measurement, monitoring, protection, control, and self-diagnostics in one package. It was widely used in power distribution switchgear worldwide before being discontinued in 2001.
The REF542plus is the recommended replacement—functional compatible in nearly all aspects with a replacement kit that allows mounting in the same panel location without door modifications. Existing wiring harnesses can be reused with only minor adaptations, resulting in short downtime during swap-out.
Frequently Asked Questions
Q: Does it support hot-swapping?
A: Honestly, no. This is a bay control and protection unit tied to trip circuits and I/O. You must isolate the bay, disable trip outputs, and follow lockout-tagout before removing the unit.
Q: Is it obsolete? Are there direct replacements?
A: Yes—REF542 has been inactive since 2001. ABB officially recommends REF542plus as the replacement. Functional compatibility is nearly 100%, and a replacement kit exists for drop-in mounting without panel changes.
