Buchholz Relay

Early Fault Detection. Lasting Transformer Protection.

The Buchholz Relay is a proven control and protective device designed to detect abnormal effects of dielectric failure inside a transformer. It is mounted between the transformer tank and the conservator, allowing gases generated within the transformer to flow into the relay and activate alarm or trip circuits in case of abnormal activity.

Constructed with a die-cast aluminium body and powder-coated finish, the relay is built for durability and reliable field performance. Clear viewing windows on both sides ensure easy monitoring of the floats and oil levels, while magnetic reed switches connect seamlessly to the terminal box. A ball valve is integrated for safe release or collection of gases for analysis, and a drain cock at the bottom further enhances convenience. For added assurance, manual verification of the relay is possible through the top cover.

In operation, gases produced during incipient faults accumulate in the relay, causing the top float to trigger an alarm. If oil flow exceeds preset thresholds, the bottom float operates to trip the circuit, automatically returning to its original position once oil levels stabilize. By eliminating mercury switches, incorporating an in-built switch testing facility, and providing clear visual monitoring, Precimeasure’s Buchholz Relay combines safety, reliability, and ease of maintenance.