Winding Diagrams – Gilead Power Engineering Service Limited
Technical Reference

Winding Diagrams

A comprehensive visual reference library for electric motor, transformer, and coil winding configurations — used by our engineers and trainees every day.

Motor Winding Diagrams

Visual schematics of the most common stator and rotor winding patterns used in single-phase and three-phase induction motors.

Three-Phase Star (Y) Winding

Standard configuration for 3-phase induction motors — all phase windings meet at a common neutral point.

N U Phase U V Phase V W Phase W Star (Y) — 3-Phase Stator

Specifications & Parameters

ConfigurationStar (Y) / Wye
Phases3-Phase
Neutral PointCommon (N)
VoltageLine = √3 × Phase
CurrentLine = Phase
Typical UseIndustrial motors, star-delta starters
Starting MethodStar-Delta (Y-Δ)
Power Factor0.8–0.95 (loaded)
Engineer’s Note Star winding reduces starting current to 1/3 of delta value — ideal for large motors requiring soft starting. At Gilead, we use this configuration for most 3-phase motor rewinds above 5.5 kW.
3-Phase Star / Y Induction Motor Recommended
Phase U
Phase V
Phase W
Stator Slots

Three-Phase Delta (Δ) Winding

High-torque configuration — phase windings connected in a closed triangular loop, no neutral point.

U1 U2 Phase U V2 Phase V Phase W Delta (Δ) — 3-Phase Stator

Specifications & Parameters

ConfigurationDelta (Δ)
Phases3-Phase
Neutral PointNone
VoltageLine = Phase
CurrentLine = √3 × Phase
Typical UseHigh-torque, running configuration
Starting MethodDOL or Star-Delta (run mode)
Power Factor0.85–0.95 (full load)
Engineer’s Note Delta configuration delivers full line voltage across each winding, providing maximum torque. We use delta as the running configuration in star-delta motor starters for pumps and compressors.
3-Phase Delta / Δ High Torque
Phase U
Phase V
Phase W

Single-Phase Induction Motor Winding

Main and auxiliary (starting) winding arrangement for single-phase motors used in household and light industrial equipment.

R Main Winding M1 M2 Aux A1 A2 Cap. Single-Phase — Main & Auxiliary Winding

Specifications & Parameters

TypeSingle-Phase Induction
Main WindingLow resistance, thick wire
Auxiliary WindingHigh resistance, thin wire
Phase Displacement90° mechanical
Starting AidCapacitor or centrifugal switch
Typical Rating0.25 – 5.5 kW
Typical UseFans, pumps, compressors, fridges
Supply220–240 V AC, 50 Hz
Engineer’s Note The auxiliary winding creates a phase shift for starting torque. It is disconnected by a centrifugal switch (or capacitor remains for PSC motors) once the motor reaches ~75% of rated speed.
Single-Phase Capacitor Start PSC Motor
Main Winding
Auxiliary Winding
Rotor

Transformer Winding Diagrams

Cross-section and schematic views of primary and secondary winding configurations used in power and distribution transformers.

Core-Type Transformer — Cross Section

Primary and secondary windings wound concentrically on each limb of the laminated iron core.

P1 P2 PRIMARY (N1) S1 S2 SECONDARY (N2) Φ flux Core-Type Transformer Cross Section

Specifications & Parameters

TypeCore-Type, Single-Phase
Primary WindingN1 turns, Input voltage
Secondary WindingN2 turns, Output voltage
Turns RatioN1 / N2 = V1 / V2
Core MaterialSilicon steel laminations
Flux pathThrough central limb
InsulationVarnish / epoxy resin
Typical UseDistribution, power supply
Engineer’s Note The turns ratio determines voltage transformation. A step-down transformer with N1=500, N2=50 turns gives a 10:1 ratio, reducing 240 V to 24 V. Gilead specialises in rewinding both core-type and shell-type designs.
Core-Type Step-Down Step-Up Key Service
Iron Core (Laminations)
Primary Winding (N1)
Secondary Winding (N2)
Magnetic Flux (Φ)

Coil Winding Types & Patterns

Visual comparison of the main coil winding methods used in electrical engineering — each suited to different applications and performance requirements.

Lap Winding vs Wave Winding

The two fundamental DC armature winding configurations — used in DC motors and generators.

LAP WINDING WAVE WINDING Parallel paths = poles (P) Coils overlap at each slot Parallel paths = 2 (always) Coils span full armature DC Armature Winding Types

Comparison Table

PropertyLap
Parallel paths= No. of poles (P)
Current capacityHigh (multiple paths)
VoltageLower
Best forLow-voltage, high-current DC machines
PropertyWave
Parallel pathsAlways 2
Current capacityLower
VoltageHigher
Best forHigh-voltage, low-current DC machines
Engineer’s Note In motor rewinding, determining the correct winding type from the original coil data is essential. Gilead’s engineers always record pole pitch, coil span, and commutator segments before stripping any winding.
Lap Winding Wave Winding DC Motor
Lap winding coils
Wave winding coils
Commutator segments

Motor Connection Diagrams

Terminal connection diagrams for star-delta starters, dual-voltage motors, and direction reversal — critical for correct motor installation and rewinding.

Star-Delta (Y-Δ) Starter Terminal Connections

How to connect a 6-terminal 3-phase motor for star-delta starting — reduces starting current by up to 66%.

Terminal Box U1 V1 W1 U2 V2 W2 STAR (Y) — Starting U1 → L1 (supply) V1 → L2   W1 → L3 U2-V2-W2 linked together DELTA (Δ) — Running U1 → L1     W2 → U1 V1 → L2     U2 → V1 W1 → L3     V2 → W1 L1 L2 L3 Y-Δ Starter Terminal Wiring

Wiring Instructions

Starting (Star Y)U2, V2, W2 shorted together
Running (Delta Δ)W2→U1, U2→V1, V2→W1
Supply toU1 (L1), V1 (L2), W1 (L3)
Starting current33% of DOL starting current
Starting torque33% of DOL torque
Changeover speed~75–80% of rated speed
Timer setting5–15 seconds (load dependent)
Motor terminals6 terminals required
Engineer’s Note Star-delta starters are the most common method we install for motors above 5.5 kW. The motor must be designed for delta operation at the supply voltage. A 415 V motor must have windings rated at 415 V for delta (not 240 V star).
Star-Delta 3-Phase Starter Most Common
U1, V1, W1 terminals (supply end)
U2, V2, W2 terminals (winding end)
Star link bar

About This Winding Diagram Library

This page is a living technical reference compiled by the engineers and instructors at Gilead Power Engineering Service Limited — updated regularly as we expand our training curriculum.

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Diagram Categories

Motor windings, transformer windings, coil types, and connection diagrams — all in one place.

10+

Individual Diagrams

Each diagram includes specs, engineer’s notes, and colour-coded legends for clarity.

100%

Field-Tested

Every diagram reflects real-world configurations our team uses in motor repair and rewind jobs.

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Open Reference

This guide is free for students, engineers, and technicians. No login required.

How to use these diagrams

Each tab covers a category of winding configurations. Within each tab, diagrams are presented with:

  • An SVG schematic drawn to represent real electrical conventions
  • A specification table with key parameters
  • An engineer’s note from our field experience at Gilead
  • Application tags identifying where each configuration is used
  • A colour legend for all lines and symbols in the diagram
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