The annual diesel generators tests of the Meyrin site, SPS, Prévessin, North Area, LHC1 to LHC8 and LHC1.8, are planned on Tuesday, 16 December 2025 from 6:00 am to 6:30 am.

Power will be cut in the following networks: Normal, General Services, Stable (18 kV, 3.3 kV, 230 V, 400 V) on the Meyrin site, SPS, Prevessin, North Area, LHC1 to LHC8 and LHC 1.8, and the machine networks (18 kV and 400 V) at LHC1 and LHC1.8.

During this outage, the uninterruptible power supply (UPS) systems will run on their batteries.

The EN-EL Group recommends that you turn off your critical equipment and computer equipment.

For any further information, please refer to the "note de coupure".