Electrical equipment shall comply with EN 50152 (Railway applications – Fixed installations – Particular requirements for alternating current switchgear).2.2.2.3.1 Low voltage D.C. Power (control) supplyThe nominal battery voltage is 110 V DC according to EN 60077-1 and EN 50155. Static tolerance range is -30% and +25%.The earthing system for the battery system is an IT-system.The system shall perform its function to the specification under all conditions of the EN 50155.Standard Voltage supply interruption test shall be in accordance with EN 50155 Class S22.2.2.3.2 Low voltage A.C. power (auxiliary) supply