Motor Starting Method Comparison Card — DOL, Star-Delta, Soft-Starter, VFD

Choosing the wrong motor starting method wastes money, causes nuisance trips, and can damage driven equipment. This A4 landscape reference card compares the four most common starting methods in a structured matrix: Direct On-Line (DOL), Star-Delta (Y-Δ), Soft-Starter, and Variable Frequency Drive (VFD). For each method, the card shows starting current as a multiple of full-load amps (DOL: 6–8× FLA, Star-Delta: 2–3× FLA, Soft-Starter: 2–4× FLA, VFD: 1–1.5× FLA), starting torque as a percentage of full-load torque, typical voltage dip at the switchboard, relative cost, wiring complexity, and applicable IEC 60034-12 starting categories. The reverse side covers practical selection guidance: when to use DOL (motors below 7.5 kW on strong supplies), when Star-Delta is appropriate (light-load starting with transient torque dip acceptable), when soft-starters make sense (conveyor and pump applications), and when VFDs are justified (variable speed, energy savings, process control). A quick-reference decision tree helps you select the right method based on motor size, supply capacity, load type, and budget. Scan the QR code for our online motor current calculator.