Adjusting sensitivity and tripping times
The sensitivity IΔn can be set from 0.03 to 30A while the tripping times from 0 to 5 seconds, thus ensuring flexibility for many applications.
If the alarm function is ON, the alarm contact switches when the fault current exceeds 60% of the threshold IΔn selected.
The new range of ELR residual current relays allows, through a selector switch, to enable or not the fail safe function. If Fail safe is OFF, the relay activates the shunt-trip once the fault current is detected and also when there is no connection between the relay and toroid. If Fail safe is ON, the relay activates the shunt-trip also when there is lack of supply to the residual current relay. The Fail safe prevents the line from not being protected when there is no auxiliary power to the device.
The output contacts of the ELR residual current relays can be reset remotely, using push buttons.
When the fault will be removed from the network, the relay contacts will switch automatically, without the need to press the reset button from a local or remote position.
This feature makes the relay stronger in presence if currents with harmonic components that are not due to an effective fault in the circuit but they are typically caused by the presence of electronic filters (e.g. when using frequency converters driving motors)
The fault memory turns on in case of a fault and is only resettable manually. In this way it is possible to know if the relay has tripped even if the fault is no longer present and the contacts have returned into the standard position thanks to autoreset.
The digital display allows instant reading of the value of earth leakage current. It is possible, through a minidip, to block the display on the residual current value that has generated the intervention of the circuit breaker.