The ABB CEM11 device is used in motor feeders to detect leakage currents and ground faults sometimes caused by insulation failures. Detection of such ground faults can be used to interrupt the motor to prevent further damage, or to alert maintenance personnel to perform timely maintenance.
The CEM11 checks that the sum of the currents flowing through it is zero (factorial addition). If the sum is zero, no residual current is present. If the residual current is above an adjusted threshold value, the output signal of the CEM11 changes.
Main features
• Just four products cover a wide residual current range of 80mA – 13.6A
• Simple residual current adjustment with a rotary switch including test position
• The output operates like a contact and can control an input that meets the IEC61131-2 requirements for 24 V signals (e.g. digital inputs of the UMCs)
• Flexible mounting options on a DIN rail on certain models, or with screws/clips
