This guide presents practical circuit solutions to help prevent unintended activation or deactivation, with a focus on time and impulse relay configurations. In industrial settings, one well-known safety method is the two-hand start system. Precautions for Safe Use Observe the following precautions to ensure safety. Do not touch the terminal section (charged section) of the Relay or Socket while power is being supplied. Electric shock may. Safety-related work practices shall be employed to prevent electric shock or other injuries resulting from either direct or indirect electrical contacts, when work is performed near or on equipment or circuits which are or may be energized. Protective relaying serves many functions including isolating faulted circuits or equipment from the remain-der of the system so the system can continue to function. This handbook covers the code of practice in protection circuitry including standard lead and device numbers, mode of connections at terminal strips, colour codes in multicore cables, dos and donts in execution. Therefore, the whole system has gone down, even though many circuit breakers have remained closed.