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residual current device

British  

noun

  1.  RCD.  a circuit-breaking device installed in electrical equipment to protect the operator from electrocution

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

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“Don’t use electrical garden tools such as a lawnmower or hedge-trimmer without a residual current device,” Buckle warns.

From The Guardian