Protection against indirect contact
The problem of indirect contacts is closely related to the problem of frame faults.
Any spurious connection between the traction circuit and the vehicle frame is
regarded as a fault. Frame faults can lead to several hazards:
• short circuits
• electrocution
• uncontrolled operation
Following measures should be taken to avoid these hazards:
• a fuse shall be built inside the battery pack, preferably in the electrical centre of
the battery
• the vehicle frame shall be isolated from the traction circuit and shall not form
any part of the power electrical circuit
• all conductive parts of the vehicle, particularly accessible parts or parts adjacent
to electrical equipment shall be connected with an equipotential connection.
• frame fault leakage detection shall be included in routine maintenance;
permanent frame fault monitoring is mandatory for certain vehicles.