Electrical & Wiring Reference

⚡ Voltage Standards

120V AC (North America)

Voltage: 120V AC, 60Hz | Region: USA, Canada, Mexico, Japan
Applies to: Washers, Dryers, Dishwashers, Refrigerators, Microwaves, Disposables, Window ACs
Wire gauge: 14 AWG (small appliances), 12 AWG (dryers, ranges, wall ovens) | Breaker: 15A or 20A
Wire colors: hot: Black or Red, neutral: White, ground: Green or Bare Copper
Notes: Most common US household voltage. 3-prong grounded plug (hot, neutral, ground).

240V AC (North America)

Voltage: 240V AC, 60Hz | Region: USA, Canada, Mexico, Japan
Applies to: Electric Dryers, Ranges/Ovens, Wall Ovens, Some Large AC Units, Heat Pumps
Wire gauge: 10 AWG (ranges, wall ovens), 8 AWG (large dryers, some heat pumps) | Breaker: 30A (4-prong dryer), 40-50A (ranges), 50-60A (wall ovens)
Wire colors: hot1 (L1): Black, hot2 (L2): Red, neutral: White, ground: Green or Bare Copper
Notes: Two hot wires (L1, L2) at 120V each. 4-prong plug: two hots, neutral, ground. 3-prong legacy: shared neutral/ground — should be upgraded to 4-prong.

230V AC (Europe)

Voltage: 230V AC, 50Hz | Region: EU, UK, Australia, China, most of Asia/Africa
Applies to: All appliances
Wire gauge: 1.5mm² (lighting/small appliances), 2.5mm² (appliances), 4mm² (cooktops/ranges) | Breaker: 16A (standard), 32A (cooktops/ranges)
Wire colors: hot (L): Brown, neutral (N): Blue, ground (PE): Green/Yellow
Notes: Single-phase. Schuko (EU) or 3-pin (UK) plugs. 230V is nominal — actual supply is 220-240V.

400V Three-Phase (Commercial/EU)

Voltage: 400V AC (L-L), 50Hz | Region: EU commercial, large installations
Applies to: Commercial refrigeration, large industrial dryers/washers, some commercial ranges
Wire gauge: 4mm² per phase (standard), 6-10mm² (high current) | Breaker: 16A-32A per phase
Wire colors: phase L1: Brown, phase L2: Black, phase L3: Grey, neutral (N): Blue, ground (PE): Green/Yellow
Notes: Three phases (L1, L2, L3) at 400V between phases, 230V between any phase and neutral. Phase rotation matters for 3-phase motors.

🔌 Wire Color Conventions

North America (NEC)

NEC (National Electrical Code) standard colors

Black — Hot (Line 1)

Red — Hot (Line 2) or switch leg

White — Neutral (or Hot in switched leg configurations)

Green/Bare — Ground (protective earth)

Blue — Secondary neutral or control circuit (non-standard use)

Yellow — Secondary hot or control circuit (non-standard use)

Orange — Control circuit (non-standard use)

Europe (IEC 60446)

IEC 60446 standard colors (EU, 2004+)

Brown — Live (L) — single phase / Phase 1 — three phase

Blue — Neutral (N)

Green/Yellow — Protective Earth (PE) / Ground

Black — Phase 2 (three phase only)

Grey — Phase 3 (three phase only)

Internal Appliance Wiring

Internal appliance wiring is NOT standardized by color. Always trace wires or use a multimeter.

⚠️ Never assume wire colors inside an appliance. Manufacturers use inconsistent color coding. Always verify with a multimeter before making connections.

🔗 Common Connectors

JST-XH 2-pin 2.5mm · 22-24 AWG

Uses: Temperature sensors (thermistors), Thermostats, Low-current signals

Most common sensor connector. 2-wire = resistance (thermistor), 3-wire = RTD or active sensor.

JST-XH 3-pin 2.5mm · 22-24 AWG

Uses: RTD sensors, 3-wire thermistors, Some motor controls

Pigtail connectors. Check for color coding to identify which pin is which.

Molex Mini-Fit 45667 3.96mm · 22-24 AWG

Uses: Water inlet valves, Detergent dispensers, Low-voltage power

Quick-connect. Push to connect, pull tab to disconnect.

Spade terminals N/A (screw terminal) · 12-16 AWG

Uses: Motor connections, Heating elements, High-current circuits

Crimp or solder. Always secure under screw terminal — no loose wires. Torque to manufacturer spec (usually 6-10 in-lbs).

Ring terminals N/A (screw terminal) · 10-14 AWG

Uses: Permanent high-current connections, Main power input, Motor terminals

For permanent connections. Torque spec varies by terminal size.

4-prong dryer plug (NEMA 14-50) N/A (plug) · 10 AWG

Uses: Electric dryers (4-prong)

4 pins: 2 hot (L1 black, L2 red), neutral (white), ground (black or green). 50A, 240V. Replaces legacy 3-prong NEMA 10-30.

3-prong range plug (NEMA 14-50) N/A (plug) · 8-6 AWG (depends on amperage)

Uses: Electric ranges, wall ovens, cooktops

Same physical plug as 4-prong dryer but different pinout. 40-50A. L1, L2, neutral, ground.

12V DC automotive N/A · varies by current

Uses: RV/truck appliances, Some mobile units

12V DC, polarity matters (+ and -). Red = +, Black = -.

⚙️ Motor Specifications & Testing

PSC (Permanent Split Capacitor) 120V AC

Applies to: Refrigerators, Dishwashers, Some Dryers
Winding: 2 windings (run + start) + capacitor
Test: Resistance: Run winding 10-50Ω, Start winding 100-500Ω, Start+Run (across terminals) = sum. Cap: 5-50μF, ±10%.
Common failure: Capacitor degradation (most common), winding burnout (less common)

Universal (Series Wound) 120V AC or DC

Applies to: Mixer, Blender, Some Dryer Motors
Winding: Stator + armature, series-wound
Test: Stator: 10-100Ω. Armature: 1-20Ω. Brush: check for wear (min length 50% of new).
Common failure: Brush wear, bearing failure, armature short

Induction (Squirrel Cage) 120V or 240V AC

Applies to: Washers, Industrial Dryers
Winding: Single or dual winding
Test: Winding resistance: 1-20Ω. Insulation (megohm): >1MΩ to ground. No continuity between windings.
Common failure: Bearing failure (most common), winding insulation breakdown

BLDC (Brushless DC) 24-48V DC (from inverter board)

Applies to: Modern High-End Washers/Dryers (Bosch, Miele, LG, Samsung)
Winding: 3-phase, hall sensor feedback
Test: 3 windings: 1-10Ω each (balanced). Hall sensor: 3 wires, 0-5V logic. Inverter board: check for blown fuse, dead IGBTs.
Common failure: Inverter board failure (most common), bearing failure, hall sensor drift

Compressor (Hermetic) 120V or 240V AC

Applies to: Refrigerators, Freezers, AC Units
Winding: 3 terminals: Common (C), Run (R), Start (S)
Test: C-R: 5-30Ω. C-S: 20-100Ω. R-S: = (C-R) + (C-S). Ground: no continuity. Cap: 5-50μF (start) + 5-20μF (run).
Common failure: Capacitor, overload, winding short. Use clip-on ammeter to check running current — locked rotor draws 3-5x rated current.

⚠️ Safety Reference

Before Any Repair

UNPLUG the appliance. For gas: close the gas valve.

Discharge capacitors: microwave HV cap (1μF/2000V) — use 1kΩ/50W resistor. Wait 60+ seconds after unplugging.

Photograph connector positions before disconnecting.

Use insulated tools for any live testing.

Only one live test at a time. Never work on a live circuit with both hands.

Multimeter Settings

Continuity (beep): check for shorts, open circuits, fuses

Resistance (Ω): check windings, heating elements, sensors

AC Voltage (V~): check power supply, motor terminals

DC Voltage (V-): check inverter board outputs, sensor signals

Capacitance (F): check capacitors (discharge first!)

Typical Torque Specs

Terminal screws (6-10mm)6-10 in-lbs (0.7-1.1 Nm)

Heating element terminals8-12 in-lbs (0.9-1.4 Nm)

Motor mounting bolts (M6)25-35 in-lbs (2.8-4.0 Nm)

Motor mounting bolts (M8)50-70 in-lbs (5.7-8.0 Nm)

Drum axle boltPer manufacturer (often 100-200 ft-lbs for drum)

⚡ Electrical & Wiring Reference