Protection
4 articles on protection.
04 Nov 2026 · 5 min read
RCD types AC, A, B: which one where
A Type AC residual current device is blind to the fault current modern electronics produce. The type letter is the difference between protection and a device that stays silent while someone is being shocked.
04 Nov 2026 · 4 min read
MCB breaking capacity: 6 kA or 10 kA?
Breaking capacity is not about the load, it is about the fault current the installation can deliver. Getting it wrong does not trip the breaker - it destroys it.
02 Nov 2026 · 4 min read
IP ratings: what IP65, IP67 and IP69K mean
The two digits in an IP rating answer two different questions, and only one of them is about water. Here is what each level is actually tested against, and why IP68 tells you less than IP67.
01 Nov 2026 · 5 min read
Reading a circuit breaker trip curve
A trip curve is the only honest document about what a breaker will do. Here is how to read the two axes, what B, C and D actually mean, and why a 16 A breaker trips on a 3 kW motor.