Electrical wiring color coding standard for three phase electrical applications are standardised to aid the identification of individual wire phases. Wiring colour codes for AC and DC power distribution circuits have changed on numerous occasions and vary depending on region. For three phase electricity supply, circuits will use five wires: earth wire, neutral wire, live wire, line 2 wire, line 3 electrical wire. This article details the following cable colour codes:
- International Wiring Colors
- US Wiring Color Codes
- Old & New UK Wiring Colors
Fixed wiring electricity supply requires specific wiring colour regulations (bs 7671) to identify different power lines in different countries. The USA have their own wiring colors for electrical circuits, black, red, and blue are used for 208 VAC three-phase; brown, orange and yellow are used for 480 VAC. Australia also have a different wiring colour standard. The UK's new cable colors for plugs are now harmonise with Europe's power cable colors for AC & DC. Most of Europe abides by IEC ('International Electrotechnical Commission') electrical wiring colors code for AC branch circuits.
In the USA, color codes are usually utilized for power wires in “branch circuits,” the wiring between the last protective device.
Industrial motors and equipment typically have higher voltage systems. Phase 1 - Brown Phase 2 - Orange Phase 3 - Yellow Neutral - Gray Ground - Green, Green with Yellow Stripe, or Bare Wire
It is very important to have a documented wire labeling system for higher voltage systems. Labels should include information regarding the circuit, and the appropriate disconnection point for lockout/tagout.
DC or Direct Current, is typically used in battery systems and solar power systems, instead of AC or Alternating Current. Positive (non-ground) - Red Negative (non-ground) - Black Ground - White or Gray