Zs Values and Cmin

In a TN earthing system the cornerstone of protection against electric shock is that the protective device ‘circuit breaker’ shall not exceed it’s maximum disconnection time. For a 230 v to earth TN system (covers both single phase and 3-phase) that is 0.4 seconds (final circuits less than or equal to 32A) see T41.1  and 5 seconds (distribution circuits and >32A) see … Read more

Not Going Green!

The clock is ticking. Remember if you are studying for the 17th Edition 2382-12 exam you only have until the end of June 2015 to take the exam! We and other providers will not be taking bookings for the 2382-12 after 31st May 2015. If you don’t think you can complete the course by then … Read more

Cables and 522.6 Amendment 3

Finally, cables in walls, ceiling and under floors a breath of fresh air and some common sense… 522.6 Impact 522.6.201 Cables under floors and above ceilings They should be 50mm clear from the top or bottom or… Use Regulation 522.6.204 see bottom of post 522.6.202 Cables in wall less the 50mm from the surface shall … Read more