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Star–Delta Connection

BETADesktopEN · RU · ESSimulator · Engine

Test your knowledge of the star–delta starter: wire it, set it and troubleshoot it. The case is a ship’s main fire pump: a 37 kW, 440 V motor on a platform supply vessel.

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This trainer needs a computer screen. Open this page on your laptop.

The 3D platform supply vessel CHIEF ONE in the Star–Delta Connection trainer

What you do

  • Lessons: 16 cards and an 11-question quiz on star and delta.
  • Connection: wire the power circuit and label the control circuit.
  • Settings: set the star–delta timer and the overload relay, then pass an exam-style starter check.
  • Troubleshooting on board: fire-drill scenarios with hidden faults (S1 left in LOCAL, a shut valve, reversed rotation, blackout) and a debrief.
  • A 2D fire main mimic and a 3D model of the vessel with an X-ray view.

Before you start

A desktop or laptop with a current browser. The 3D view needs WebGL 2; without it the 2D schematic works the same. Your progress stays in your browser.

For training only. Models are simplified; class rules and IMO texts are the authority.

Learn the theory

  1. 01How a star–delta starter worksStar and delta on a 440 V ship’s supply: why a cage motor draws six times its full-load current, and how a star start cuts it to a third at a third of the torque.
  2. 02Motor starting and generator voltage dipHow far a motor start pulls a ship’s generator voltage down, the estimate x·k ÷ (1 + x·k), and the limits in IACS UR E5, UR E13 and IEC 60947-4-1.
  3. 03Star–delta changeover: timer setting and interlockThe star–delta changeover step by step, how to set the timer (80–90 % of synchronous speed) and why the star and delta contactors must never close together.
  4. 04Overload relay setting and direction of rotationWhy a star–delta overload relay is set to FLC ÷ √3 = 0.58 × FLC, how a fire pump ends up turning backwards, and how to reverse a star–delta motor safely.
  5. 05Starting methods on board: DOL, star–delta, soft starter, VFDDirect-on-line, star–delta, soft starter or frequency converter on a ship, and what a starter does after a blackout: low-voltage protection (LVP) or release (LVR).
  6. 06The fire main isolating valve and the emergency fire pumpWhy the engine room part of the fire main has an isolating valve (SOLAS II-2/10), how the emergency fire pump and SDNR valves work together, and the test.

All guides on one page → Star–Delta Connection guides · Guías en español