MCCB Discrimination and Selectivity Coordination
How MCCB discrimination (selectivity) works between series breakers: current and time grading, ZSI, partial vs total discrimination, and how to read a manufacturer's selectivity table.
10 min read
Technical
Selectivity guides
Guides and notes on industrial electrical and automation parts: selection, wiring, settings and ordering.
- Articles
- 15
- Latest
MCB Discrimination and Selectivity Explained
Why two MCBs in series often trip together on a large fault, what current discrimination actually guarantees, and when an upstream MCCB or fuse is the only fix.
10 min read
RCD Selectivity: S-Type vs Instantaneous Discrimination
How S-type selective RCDs coordinate with downstream instantaneous devices using the 2x current ratio and time-delay rule from IEC 60947-2 and IEC 61008-1.
9 min read
Molded Case Circuit Breaker (MCCB) Guide: How It Works, Sizing, and Buying Tips
MCCB sizing, breaking capacity, and trip unit selection explained for industrial feeders from 100 A to 1600 A with ABB Tmax XT examples. Shop at Stoklink.
32 min read
ABB SACE Emax 2 in MV LV Main Switchboards for Industrial Plants
ABB Emax 2 sizing, selectivity, and MV LV coordination for industrial main switchboards, plus frame selection for incomers and bus-ties. Shop at Stoklink.
19 min read
ABB SACE Emax 2 in Data Center Main Distribution Boards: Design Guide
ABB Emax 2 design guide for data center MDBs: sizing, selectivity, Ekip trip units, and Tier III/IV coordination with Tmax XT breakers. Shop at Stoklink.
14 min read
ABB Emax 2 as Bus Tie Breaker in Double Busbar Configuration Guide
ABB Emax 2 as bus tie breaker in double busbar: sizing, Ekip trip unit setup, interlocks, and selectivity for critical LV switchgear. Shop at Stoklink.
20 min read
ABB Emax 2 Selectivity and Coordination with Downstream Breakers Guide
Learn how to calculate ABB Emax 2 selectivity and coordination with downstream breakers using IEC 60947-2 methods and real project examples. Shop at Stoklink.
23 min read
ABB Emax 2 Arc Flash Mitigation and Zone Selective Interlocking Guide
ABB Emax 2 arc flash mitigation and ZSI guide: Ekip trip unit settings, wiring topology, and IEEE 1584-2018 calculations for safer panels. Shop at Stoklink.
19 min read
ABB Emax2 Air Circuit Breaker Review and Full Specifications Guide
Discover the ABB Emax2 air circuit breaker full specifications, frame sizes, Ekip trip units, and selection guidance for your next project. Shop at Stoklink.
16 min read
ABB SACE Emax 2 Air Circuit Breaker: Selection, Application and Maintenance Guide
ABB Emax 2 air circuit breaker selection, sizing, trip units, selectivity, and maintenance guide for 630 to 6300 A LV switchgear engineers. Shop at Stoklink.
27 min read
How to Set Overcurrent Protection Trip Settings on an ACB: Engineer Guide
Master ACB Trip Settings for L, S, I, and G protection per IEC 60947-2 with worked examples, selectivity rules, and brand-specific tips. Shop at Stoklink.
21 min read
Air Circuit Breaker in Low Voltage MNS Main Switchboard: Complete Guide
ABB MNS system ACB sizing, frame selection, selectivity, and cubicle fit explained for low voltage main switchboard incomers 630-6300 A. Shop at Stoklink.
19 min read
Air Circuit Breaker for Data Center Power Distribution: Selection Guide
ACB sizing for data center power distribution: frame ratings, Icu vs Ics, LSI trip units, 2N topology, and procurement specs explained. Shop at Stoklink.
14 min read
Air Circuit Breaker for Generator Incomer Protection: Sizing Guide
ACB sizing for generator incomer protection covers subtransient reactance, frame selection, trip unit setup and Icu coordination steps. Browse at Stoklink.
16 min read
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