All work equipment must be provided with suitable means of isolating it from all sources of energy in order to make it safe for maintenance and other circumstances. To be suitable the break in energy supply • must be established in a secure manner, and • cannot be inadvertently reconnected. • Suitable systems range from unplugging a piece of equipment to locking off an isolating switch or valve or using a locking device with multiple locks and keys. • Where some energy sources must be retained for safety reasons, the isolation procedure must identify measures to be taken to overcome any risks arising. • Restraints, barriers or shielding must be installed to prevent injury from internal energy of the equipment . • Reconnection of energy sources: ? Measures to be taken to ensure reconnection does not expose anyone using the equipment to risk. ? Reconnection must not initiate movement or other hazards. ? Measures are required to ensure that guards and other protection devices are functioning correctly before operation begins.