Providing Protection Against AC & Rectified AC Fault Currents
Pure AC is the simplest current to detect.
However, this becomes more complex when we look at appliances where the current is rectified or the product has in-built power control, for example a dimmer switch or a washing machine.
The vast majority of these power controls use thyristors to rectify or chop up the AC current, changing its composition. The AC current may now comprise of either positive or negative going half cycles only, or positive or negative going pulses of current of less than half cycle curation.
Whilst the RCD current transformer can still detect these chopped up waves it is no longer dealing with a pure sine wave, and detection of such pulses becomes more difficult. Detecting these distorted currents is a complex operation and it is something that Western Automation has been doing successfully for many years. We have developed specialised RCD technology that detects all types of fault currents derived from an AC source. Our technology has the capability to detect pulsating DC chopped waves, half waves as well as full AC.
These RCDs are known as A-Types and are the only RCDs that have the capability to provide protection against all known AC type and derived electrical faults from an AC source.