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Electrical & Electronics Engineering vocabulary · Wiring, Protection and Safety

RCD

Meaning in electrical & electronics engineering, with examples

abbreviationCommon term

In electrical & electronics engineering, RCD means: Short for residual current device: a protective device that switches off a circuit when it detects current leaking to earth, for example through damaged insulation or a person. 30 mA devices are common for protecting people.

In Turkish: kaçak akım rölesi, kaçak akım koruma şalteri

How it is used

Used in building installations and on construction sites. An RCD trips, and its test button is pressed regularly to check it. Related names are RCCB, RCBO (with overcurrent protection) and, in North America, GFCI. Engineers talk about the RCD rating and nuisance tripping.

Example sentences

  1. The RCD trips whenever the washing machine starts heating, so its heater may be leaking.

  2. Press the test button on the RCD to make sure it still works.

Common collocations

  • RCD trips
  • 30 mA RCD
  • RCD test button
  • nuisance tripping
  • circuit breakerAn automatic switch that opens a circuit when it detects too much current, for example from an overload or a short circuit. Unlike a fuse, it can be reset and used again.
  • electric shockThe effect of electric current passing through the body when a person touches a live part. It can cause burns, muscle spasms or heart rhythm problems, and it can be fatal.
  • groundThe common reference point of a circuit, taken as 0 V, or a safety connection to the earth. In electronics it is marked GND; in installations it is the protective earth conductor.
  • distribution boardAn enclosure that divides an incoming supply into separate circuits, each protected by its own breaker or fuse. In North America it is usually called a panelboard or breaker panel.
  • 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.

More terms: Wiring, Protection and Safety

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