Air Circuit Breakers

Air circuit breakers (ACBs) protect industrial plants, electrical machines, transformers, industrial transmission and distribution equipment, and generators. These devices switch off an electrical circuit in case of an over current or short circuit condition occurring downstream. If an ACB fails to operate or operates incorrectly under these fault conditions, it can cause severe damage to itself and to the equipment connected to it. This can result in huge revenue losses due to outages on the transmission lines.

In many cases, the ACB may be standing still for a number of years without operating. But, when an abnormal condition occurs, they need to operate within a few milliseconds to isolate the fault and protect the system.

ACBs contain a number of moving parts that are working in close coordination. They require periodic inspection and maintenance to ensure that they operate reliably when required. Contact timings, contact bounce, non-simultaneity of contacts, contact travel and speed measurements, tripping current characteristics, static contact resistance, insulation tests, endurance tests, etc. are some of the tests performed on ACBs.

Crest manufactures a full range of circuit breaker testing products for OEMs for ensuring the quality of the product before delivery and for end users to ensure optimum performance of their assets.