3Ph+Io overcurrent, motor protection & autorecloser
3Ph+Io overcurrent, motor protection & autorecloser
3Ph+Io overcurrent, motor protection & autorecloser
3Ph+Io overcurrent, motor protection & autorecloser
The S24 Variant 1 is used mostly as the main or backup protection of overhead lines, cable networks and motors.
It is a member of the S24 series, which is part of the EuroProt+ Smart Line. Members of the Smart Line also offer a wide range of functions but they do so in a small, compact enclosure so that they can be installed in locations with limited space available for the protection equipment.
The S24 series contain special selections of the EuroProt+ modules and functions, composed with cost effectiveness in mind. Depending on the standard configuration chosen (Variant 1, Variant2,…), the IED is adapted to the protection of medium-voltage feeders in isolated neutral, resistance earthed, compensated and solidly earthed networks. Once the application-specific settings have been defined for the standard configuration IED, it can be put into service directly. Areas of application include protection functions for a large variety of applications, e.g. transformer differential and restricted earth fault protection, frequency and voltage based protection, motor protection, thermal overload protection.
The EuroCAP configuration tool, which is available free of charge, offers a user-friendly and flexible application for protection, control and measurement functions to ensure that the IED-EP+ S24 devices are fully customisable.
Variant 1 is used mostly as the main or backup protection of overhead lines, cable networks and motors. It is a member of the S24 series, which is part of the EuroProt+ Smart Line.
The Variant 1 relay includes a variety of versatile feeder and motor protection functions such as three-phase, residual and negative sequence overcurrent protection, undercurrent protection, thermal overload protection, etc. It can be used as a back-up protection relay for downstream equipment (e.g. feeders, cables). The automatic reclosing function is also part of the standard configuration.
The IED includes a wide range of control and supervisory functions, which provide full control and user-defined interlocking schemes for the primary switchgear at the substation.
The Variant 1 configuration measures three phase currents and the residual current. The main protection functions are overcurrent functions, the thermal overload function and the undercurrent function. For motor applications, there is a start-up supervision function with restart inhibit. Capacitor protection functions are optional. The configuration is designed to meet the requirements of a medium-voltage field unit.

| Protection & control functions | IEC | ANSI | *Inst. | |||
|---|---|---|---|---|---|---|
| Loss-of-load (undercurrent) protection function | I< | 37 | 1 | 2025.08.20. | download | |
| Negative sequence overcurrent protection function | I2> | 46 | 1 | 2025.04.04. | download | |
| Broken conductor protection | I2/I1> | 46BC | 1 | 2020.06.30. | download | |
| Motor startup supervision function | Istart/I(t) | 48/66 | 1 | 2022.03.08. | download | |
| Line thermal protection function | T > | 49 | 1 | 2025.01.03. | download | |
| Motor thermal protection function | T> | 49M | 1 | 2022.07.11. | download | |
| Three-phase instantaneous overcurrent protection function | I >>> | 50 | 1 | 2025.01.17. | download | |
| Residual instantaneous overcurrent protection function | Io>>> | 50N/50G | 1 | 2025.12.09. | download | |
| Breaker failure protection functions | CBFP | 50BF | 1 | 2022.10.03. | download | |
| Three-phase time overcurrent protection function | I>, I>> | 51 | 2 | 2025.04.04. | download | |
| Residual overcurrent protection function | Io>, Io>> | 51N/51G | 2 | 2025.04.04. | download | |
| Current unbalance function (CT Supervision) | 60 | 1 | 2024.12.20. | download | ||
| Inrush current detection function | I2h> | 68 | 1 | 2024.12.20. | download | |
| Automatic reclosing function for medium voltage networks | 0 -> 1 | 79 | 1 | 2024.12.10. | download | |
| Capacitor unbalance protection for blocks in double star connection function | 51NC | op. | 2024.07.31. | download | ||
| Capacitor unbalance protection for blocks in bridge connection function | ? | 51NC | op. | 2024.07.31. | download | |
| Capacitor overvoltage protection function | ? | 59C | op. | 2024.07.31. | download |
| Brochures | |||
|---|---|---|---|
| EuroProt+ overview | 19/02/2021 | download | |
| System Description | |||
| IED-EP+ S24 general specification | 19/02/2021 | download | |
| Hardware Guides | |||
| Maintenance guide | 28/06/2023 | download | |
| Hardware description | 05/05/2025 | download | |
| IEC61850 documents | |||
| TISSUEs Implementation Conformance Statement (TICS) for the IEC 61850 Edition 2 server interface in Europrot+ product family | 18/04/2023 | download | |
| Protocol Implementation eXtra Information for Testing (PIXIT) for the IEC 61850 Edition 2 server interface in Europrot+ product family | 18/04/2023 | download | |
| Protocol Implementation Conformance Statement (PICS) for the IEC 61850 Edition 2 server interface in Europrot+ product family | 18/04/2023 | download | |
| Model Implementation Conformance Statement (MICS) for the IEC 61850 Edition 1 server interface in the Eurorot+ product family | 21/05/2012 | download | |
| Protocol Implementation eXtra Information for Testing (PIXIT) for the IEC 61850 Edition 1 server interface in Europrot+ product family | 20/03/2017 | download | |
| Protocol Implementation Conformance Statement (PICS) for the IEC 61850 Edition 1 server interface in Eurorot+ product family | 20/03/2017 | download | |
| Configuration Descriptions | |||
| Variant 1 configuration description | 30/05/2023 | download | |
| Variant 1 product configuration options | 25/02/2026 | download |