Automatic changeover schemes should be identified in these SLDs for all LV switchboards / PCCs in accordance with Section 6 Part B3 Cl 1.4.1:“Each Low Voltage Power Control Centres (PCC) shall have duplicate supply source (2x100%) from the LV auxiliary transformers through two incoming circuit breakers and one bus section circuit breaker, with provision of auto changeover from one source to the other in case of failure of one source”.