RMS-ABB.Africa
Technical guides
Selection, installation and compliance notes written against the products in this catalogue — each one linked to the order codes it applies to.
9 guides
Applications
Building a DOL motor starter panel: the five parts and what sizes each
Direct-on-line is still the right answer for most cage induction motors. The isolator, the short-circuit protection, the contactor, the overload and the control circuit — what each is chosen on,…
Lifecycle & replacement
Compact NSX <630 is discontinued — what replaces it, and how to specify the successor
Compact NSX has been superseded by ComPacT NSX. The substitution is usually straightforward; this is what has to be confirmed before you order, and why we do not publish a…
Industrial Control
Contactor vs relay: how to choose, and how to size a contactor
A contactor's current rating is not one number. AC-1 and AC-3 describe different switching duties and produce different figures for the same device — and picking the wrong one is…
General Electrical
How to read an industrial electrical datasheet
Almost every figure on a datasheet carries conditions printed somewhere other than next to the number. What Ue, Ui, Uimp, Ie, Ith and In actually constrain, how to read the…
Circuit Protection
MCB vs MCCB: what the difference actually means for your panel
The difference is not size, it is the standard each device is built and tested to — and that difference propagates into the trip characteristic, the short-circuit markings and everything…
Method
Reading an industrial order code: what each block of characters tells you
An order code is a sentence in compressed notation. Read the blocks in order, name your assumptions, and resolve them against the manufacturer rather than a pattern.
Circuit Protection
Understanding breaking capacity: kA ratings explained
Icu, Ics, Icn, Icw and Icm are five different quantities, measured by different test sequences against different criteria. What each one constrains, and how to work out which figure your…
General Electrical
Understanding IP ratings, and AC-1 vs AC-3 utilisation categories
What the two IP digits are actually tested for, why IPX7 is not a superset of IPX6, and why the same contactor carries two very different current ratings depending on…
Drives & Motors
VSD or soft starter: choosing the right motor starting method
A soft starter reduces starting current in proportion to voltage, but torque falls with its square — which decides whether it can start your load at all. A drive removes…