Guides
What an Automatic Transfer Switch Does and How to Size One
What an ATS does, why the mechanical interlock is critical, and how to choose rated current and pole count for an installation with a generator.
Guides
Guides
Choosing a Contactor: AC-1 or AC-3, and How to Read the Rating
The same contactor appears in a catalogue with two different current ratings. We explain utilisation categories, sizing by motor power and the pole count decision.
Guides
Icu, Ics, Icm and Icw: Reading the kA Figures on a Breaker Label
The four abbreviations on a circuit breaker label describe different things. Here is what each one means and which one governs your selection.
Guides
Air Circuit Breaker or Moulded Case Breaker? A Selection Guide
We compare ACBs and MCCBs on rated current, breaking capacity, short-time withstand and discrimination so you can pick the right main device.