Many faults with work equipment can be found during a simple visual inspection: 1. Switch off and unplug the equipment before you start any checks. 2. Check that the plug is correctly wired (but only if you are competent to do so). 3. Ensure the fuse is correctly rated by checking. Make sure that the electrical equipment you are intending to use is suitable for the electrical supply to which you are connecting it. Check the voltage is correct and. You should be sure that the electrical supply is safe to use. Regular tests performed by a competent person, using suitable equipment are a good way of. A Residual Current Device (RCD) can reduce the likelihood of an electrical injury but a shock can still cause very serious or fatal injuries, so an RCD should only be.