Residual current

Residual current is an unintended flow of current to ground typically resulting from an issue with electrical insulation within a load or connecting wiring.

Residual current may be measured as:

• The sum total of all currents flowing through the phase (and neutral) conductors

• The current flowing through the Protective Earth (PE) conductor in TT and TN earthing systems

The RCM meter models can be used to continuously measure residual currents in an electrical system. The RCM meter models are equipped with two input channels (I5 and I6) that require specific toroid current sensors. Each RCM channel is capable of dual alarm configuration allowing a warning alert level and a higher level over alarm. The residual current measurements are processed once per second.

WARNING
UNINTENDED OPERATION OR METER DAMAGE Do not use this device for critical control or protection applications where human or equipment safety relies on the operation of the control circuit. Do not exceed the specified current through I5 and I6 terminals. Failure to follow these instructions can result in death, serious injury, or equipment damage.

Typical applications for meters with RCM capability include:

• Leakage current measurement

• Earth (Ground) current measurement

• Automatic notification and/or digital output operation in event of leakage current alarm

• Electrical installation reliability profiling