Earth leakage sensor
Actually nearly all motors in industrial applications are protected against overload using TOLs, EOLs or intelligent motor control units such as the UMC22/UMC100. Additional surveillance with PTCs improves the protection against over temperature. Earth faults are another important reason of motor destructions (when above named protection measures are used).
The CEM11 device monitors if 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. It can be used in motor feeders to detect leakage currents respectively ground faults caused for example by insulation breakdowns. Detection of such ground faults can be used to interrupt the motor to prevent further damage, or to alert the maintenance personnel to perform timely maintenance
- With only four products a wide residual current range can be covered (80mA – 13.6A)
- Simple residual current adjustment with a rotary switch including test position.
- The output operates similar to 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 (along side or cross side, not all types) or with screws/clips