Transformers are one of the most essential and expensive element in the Power systems. Failure of Transformers or its accessories will lead to power outages and repairing of the same will be time consuming and expensive process. Hence, protecting the Transformers and its accessories from failure is of utmost importance in the smooth functioning of the Power system.

The Protective Oil Surge Relay (OSR) operates on the principle of Oil turbulence . OSR mounted in the Pipeline connecting Conservator and On-load tap-changer (OLTC). Under normal condition, the oil flow rate through the OSR will be in control. Any faults occurring in the OLTC will lead to the Pressure buildup which results in Oil turbulence. The increased Oil flow rate beyond the safe limit through OSR will trip the Transformer and thereby safeguarding the Transformer and OLTC.

OSR is suitably designed and tested to function at extreme environmental conditions and at intensive seismic levels.