2.2.4.2 EarthingIn the auxiliary th

2.2.4.2 EarthingIn the auxiliary three-phase loads, neither the three phases nor the neutral conductor are allowed to be directly connected to earth.In the battery loads, neither the plus pole or the minus pole conductor are allowed to be directly connected to earth.For protective provisions related to electrical hazards on railway vehicles EN 50153 - standard applies.All equipment potentially causing an electric shock shall be protected against direct contact.All equipment operating with voltages above 25 VAC or 60 VDC shall be earthed for safety reasons..Each earthing point of the equipment shall be designed as follows: the earthing points must be of good electrical conduction to ensure low touch voltage, the earthing points shall have large contact surface and shall be able to carry a possible short circuit current. The requirements in EN 50153 Section 6.2.1 and 6.2.2 applies.The supplier shall provide an earthing diagram of his equipment including earthing bonds and shields.The insulation resistance of the equipment to ground shall exceed 50 MOhm.Every earthing point shall be easily accessible for assembly.All bond and earth leads are to be kept as short as possible.All the earthing cables and earthing points shall be placed visibly to ensure an easy inspection and a clear understanding of the earthing path.All the protective earthing cables shall be yellow/green."The protective earthing points shall be marked with following figure and comply with EN 50153."