What caused the 10-hour communication outage at India’s Eastern grid
The Eastern Region’s power grid communication network suffered a major disruption on June 1, 2026, leaving the Eastern Regional Load Despatch Centre (ERLDC) without real-time visibility of the regional power system for nearly 10 hours.
According to discussions at the Eastern Regional Power Committee (ERPC), the outage began at 12:10 hours and affected multiple critical operational systems at ERLDC. These included Inter-Control Centre Communication Protocol (ICCP) links with all constituents, Remote Terminal Unit (RTU) and Substation Automation System (SAS) communication from substations and generating stations, Phasor Measurement Unit (PMU) and Wide Area Monitoring System (WAMS) data, Voice over Internet Protocol (VoIP) communication, Automatic Meter Reading (AMR), and Automatic Generation Control (AGC) communication with power plants.
Operations affected
The communication failure resulted in a complete loss of real-time visibility of the Eastern Region power system, affecting monitoring and system operations at ERLDC, the National Load Despatch Centre (NLDC), and the State Load Despatch Centres (SLDCs) in the region.
SCADA data was fully restored shortly after midnight on June 1. However, PMU and Phasor Data Concentrator (PDC) data remained unavailable until June 2, extending the disruption to nearly 24 hours for synchrophasor-based monitoring.
Committee to investigate
The incident follows similar communication failures reported in 2020 and 2023, prompting concerns over the resilience of the region’s communication infrastructure.
ERPC has constituted a committee, chaired by its Member Secretary, to investigate the incident. The committee will examine the root cause, reconstruct the sequence of events, analyse fault propagation, review the existing communication network architecture, and recommend both short-term and long-term corrective measures.
Power Grid Corporation of India Limited (Powergrid), Inter-State Generating Stations (ISGSs), all State Load Despatch Centres, and other concerned entities have been asked to nominate experts in communication, SCADA and cyber security within one week.
The featured photograph is for representation only.
