Wiring
3 articles on wiring.
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.
03 Nov 2026 · 5 min read
Emergency stop categories 0, 1 and 2
Category 0 cuts power at once, Category 1 brakes first and then cuts. Category 2 is not an emergency stop at all, and ISO 13850 says so.
02 Nov 2026 · 5 min read
PNP vs NPN sensors: wiring and PLC inputs
PNP and NPN describe which side of the output transistor the load sits on. Get it wrong and the sensor works perfectly but the PLC never sees it - here is how to tell them apart before you order.