How to Select a Timing Relay: Selection Guide
A five-step selection process for timing relays covering function, timing range and accuracy, supply voltage and trigger type, contact rating, and mounting format.
10 min read
Technical
Selection guides
Guides and notes on industrial electrical and automation parts: selection, wiring, settings and ordering.
- Articles
- 13
- Latest
How to Select an Interface Relay for PLC Outputs
A step-by-step guide to matching PLC output type, coil voltage and current, contact rating, and socket style when selecting an interface relay.
9 min read
How to Read an Overload Relay Coordination Table
How to read an overload relay and contactor coordination table: Type 1 vs Type 2, key columns, and trip class matching.
9 min read
How to Select a Phase and Voltage Monitoring Relay
A step-by-step selection guide for phase and voltage monitoring relays, covering function match, auxiliary supply, threshold setting, output logic, and Schneider vs ABB CM comparison.
9 min read
How to Select and Set a Thermal Overload Relay for a Motor
A step-by-step guide to reading motor nameplate FLC, matching relay range and frame, setting the dial, and picking the trip class for a thermal overload relay.
8 min read
3-Pole vs 4-Pole MCCB: Selection Guide
A clear decision rule for choosing 3-pole or 4-pole MCCBs based on TN-S, TN-C-S, TT, and IT earthing systems, neutral protection needs, and harmonic loading.
11 min read
How to Read an MPCB and Contactor Coordination Table
How to read the rows, Icc column, and Type 1/Type 2 declaration on an MPCB-contactor coordination table without breaking the tested combination.
9 min read
How to Size an RCBO for a Final Circuit
How to size an RCBO for a final circuit: matching In to design current and cable capacity, setting IΔn and type by load, and checking discrimination with the upstream device.
9 min read
How to Select and Set an MPCB for a Motor
A practical walkthrough of setting an MPCB's thermal dial to nameplate FLC, verifying the magnetic trip and trip class, and confirming Type 2 coordination with the contactor.
10 min read
How to Select an RCD: Sensitivity, Type and Poles Checklist
A step-by-step checklist for selecting RCD sensitivity, type, poles and rated current, matched to the earthing system, IEC standards, and special cases like EV chargers and VFDs.
11 min read
How to Choose the Right MCB Tripping Curve for Your Load
A load-by-load walkthrough matching MCB tripping curves B, C, D, K, and Z to inrush current so the breaker neither nuisance-trips nor under-protects the circuit.
10 min read
How to Select and Size a Soft Starter for a Motor
How to size a soft starter correctly by full-load current, IEC 60947-4-2 duty class, starting torque against the load, control method, wiring topology and protection features.
10 min read
How to Select the Right MCB: Complete Checklist
A seven-step decision path for sizing an MCB correctly, from load current and cable coordination to tripping curve, breaking capacity, poles, standard, and derating.
8 min read
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