Live Test Re-check Polarity and Functional Testing of our 2 Way and Intermediate Lighting Circuit EAL Awards City & Guilds Students training aid for checking polarity and functional testing (LIVE) under controlled conditions within a college environment our basic lighting circuit. The first live test is check polarity of supply using an approved voltage indicator. We are checking that the switches operate and that includes the MCB and the RCD which in this case is a RCCB. Videos are training aid