Abstract :
Summary form only given, as follows. A new section to BS 7671 is 717 - Mobile and Transportable Units. The Section includes requirements for the supply and the internal electrical installations of broadcasting trucks, medical services units and fire-fighting appliances including containers or cabins; vehicles will be of the self-propelled/towed or transportable type. The particular risks associated with mobile and transportable units are: 1. loss of connection to earth 2. different national or local electricity distribution networks 3. ensuring protective bonding is adequate in undefined areas external to the unit 4. open-circuit faults of the PEN conductor of PME supplies 5. shock from high-protective-conductor currents 6. vibration whilst the vehicle or trailer is in motion.
