Wago Earth fault detection

Increase availability through improved, preventive maintenance.

In accordance with the IEC 60204-1 standard, measures must be taken to reduce the probability of malfunctions due to insulation faults / earth faults in a control circuit. A widely used option is the connection of 0 V to the earth potential in the control circuit, connected to an upstream fuse. With the new earth resistance signaling module, WAGO now offers the possibility, in addition to the 0V earthing, to also fully automatically detect the undershoot of a non-adjustable, asymmetrical insulation resistance between +24 V or 0 V of the supply voltage and earth. The Iso-OK status can be signaled to a controller with an integrated potential-free contact. In addition, LEDs on the module clearly indicate the insulation fault to the operator. This significantly simplifies maintenance compared to mechanical earth wire disconnect terminals. Instead of the previously usual manual test of an earth fault about every 3 months, there is now a permanent test of the insulation resistance. Early detection of impending earth faults enables improved preventive maintenance and thus ensures increased system availability. The user can select the grounded / ungrounded control circuit operating mode using a slide switch; however, the module does not meet the requirements for insulation monitoring devices according to IEC 61557-8.


Automated measurement of insulation resistance

Early detection of looming earth faults

Signaling of insulation faults via LEDs and potential-free contacts

Availability: Q1 / 2021