A RCD (Residual Current Device) is a safety device that disconnects a circuit when it detects an imbalance of the electric current. The RCD turns the
power off almost immediately to prevent electrocution. While you may still receive an electric shock, the duration will be very short, reducing
the risk of serious injury.
Where electricity is supplied through a socket, the risk associated with that supply must be minimized by the use of a safety switch (RCD).
A RCD cannot detect all types of faults, for example if a person receives a shock between the active and neutral conductors. However these circumstances
are rare and the vast majority of incidents occur between the active conductor and earth, which is protected by a Safety Switch (RCD).
If a person comes in contact with a live electrical conductor, electricity flows through their body, causing an electric shock. Effects can vary from
a tingling sensation or muscular pain to breathing difficulties, burns, and heart failure.
RCDs are extremely sensitive, disconnecting within 10 to 50 milliseconds (The standard allows up to 300 milliseconds but this is very rare that they
reach this time and are generally deemed as failed and replaced) of detecting a leakage current. This stops the flow of electricity through someone’s
body to earth. Importantly, this response time is much faster than the critical section of the cardiac cycle, and therefore reduces the risk of
death or serious injury.
RCDs also protect against fire caused by faults in appliance, tools and wiring. If these faults go undetected they could cause a fire, or personal
injury. RCD’s provide a means of early fault detection.
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