Okuzeka
Electrical & Electronics Engineering vocabulary · Power Systems and Electrical Machines

Phase

Meaning in electrical & electronics engineering, with examples

/feɪz/nounCore term

In electrical & electronics engineering, phase means: One of the live conductors in an AC system, such as L1, L2 or L3 in a three-phase supply. It also means the timing position of a waveform, measured in degrees.

In Turkish: faz, faz iletkeni, faz açısı

How it is used

Used in installations and signal analysis. Electricians talk about phase-to-phase and phase-to-neutral voltage, a lost phase, phase rotation and balancing loads across the phases. In signals, two waveforms can be in phase, out of phase or have a phase shift.

Example sentences

  1. The motor is humming but won't start; I think we've lost a phase.

  2. There's a 30-degree phase shift between the voltage and the current.

Common collocations

  • phase-to-phase voltage
  • phase-to-neutral
  • loss of phase
  • phase shift
  • phase rotation
  • three-phaseDescribing an AC system with three voltages of the same frequency, each shifted by 120 degrees from the others. It is used to transmit power and run large motors efficiently.
  • neutralThe conductor that carries current back to the source in an AC system and is normally close to earth potential. In IEC wiring it is blue; in North America it is white.
  • ACShort for alternating current: current that changes direction many times per second. Mains electricity is AC, at 50 Hz in Turkey and Europe and 60 Hz in North America.
  • power factorThe ratio of real power (in watts) to apparent power (in volt-amperes) in an AC circuit, between 0 and 1. A low power factor means more current is needed for the same useful power.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Power Systems and Electrical Machines

Practise with graded reading

Reading at the right level is the fastest way to make new words stick. Pick free English books by level: