Functional block diagram of the S24/LD relay
General presentation
The S24/LD (V4) relay is a multifunction differential digital protection. It is mainly intended for the protection of lines and cables. It is fitted with a three-phase and earth current unit.
It belongs to the S24 family, part of the SMARTLINE range. These devices offer a wide set of functions in a compact housing. Among other uses, they are particularly suited to the LV compartments of MV switchgear cubicles.
The particularity of these relays is that, although they belong to the SMARTLINE range, their hardware and firmware are the same as those of the relays making up the PROTECTA range. They therefore share the same physical and electrical characteristics. This provides extensive field experience of their use and operation, as well as consistent and optimum manufacturing lead times. The main difference between the two ranges is the housing.
The EuroCAP configuration tool, available free of charge, provides a user-friendly and flexible application for protection, control and measurement functions, ensuring that the protection devices are fully customisable.
General features
- Native IEC 61850, Edition 2 compatible
- Standard 144 × 144 mm housing
- The predefined factory configuration can be customised to the user’s specifications with the EuroCAP tool
- Various types of HMI:
- Colour touch screen
- Monochrome (B&W) alphanumeric display with 4 touch buttons.
- Built-in web server as well as extended measurement, control and monitoring functions.
- User-configurable LCD displays for the colour touch HMI, able to show single line diagrams with position indication and control of the switching devices, as well as measurement values of the controllable objects
- Adaptive protection
- Circuit breaker monitoring and control
- High-capacity disturbance recorder (DRE) and event logging:
- DRE supporting up to 32 analogue signal channels and 64 digital signal channels
- The event recorder can store more than 10,000 events
- Various mounting types:
- Flush-mounted;
- Semi-flush-mounted;
- DIN rail
- Numerous communication protocols:
- Ethernet communication: IEC 61850; IEC 60870-5-104; DNP3.0 TCP; Modbus TCP
- Serial communication: DNP3.0; IEC 60870-5-101/103; MODBUS, SPA
- Legacy network protocols over 100Base-FX and 10/100Base-TX (RJ45)
- Optional communication ports:
- Ethernet over optical fibre (MM/ST, SM/FC),
- RJ45,
- POF serial,
- Serial over optical fibre,
- RS-485/422
- Simultaneous support of several communication protocols
- Built-in self-monitoring function (hardware and software) – Watchdog
- Various time sources available:
- NTP server;
- IRIG B
Applications
The S24/LD protection is mainly used as main or back-up protection for overhead lines or cable networks.
The board dedicated to the communication between the two remote relays sends and receives phase current vectors to perform this function. In addition, this relay integrates various versatile feeder protection functions, such as three-phase, residual and negative sequence overcurrent protection, as well as thermal overload protection, etc. It can be used as a back-up protection relay for downstream equipment (for example feeders and cables). The auto-reclosing function is also part of the standard configuration.
The S24/LD relay integrates a wide range of control and supervision functions, providing full control and user-defined interlocking schemes for the substation switchgear.
Field of application
- Cable/line differential protection function
- Protected line length of up to 50 km with single-mode optical fibre; short lines up to 1 km fitted with a single-mode optical fibre port are also supported
- Three-phase, residual and negative sequence overcurrent protection functions, as well as thermal overload protection
- The protection functions implemented provide back-up protection for downstream equipment
- Auto-reclosing function
- Circuit breaker failure protection function
- Inrush current detection
- Current transformer (CT) current unbalance detection
- Programmable interlocking schemes
Protection and control functions
The S24/LD (V4) protection measures the three phase currents and the residual current. The main function of this protection is the cable/line differential protection.
In addition, overcurrent protection functions as well as a thermal overload protection function are also available for the protection of overhead lines and cable networks. The configuration is designed to meet the protection requirements of a medium voltage link.
General documentation : Smartline S24 DataSheet – 19AA1121500B
Operation manual : S24LD OMA 23AA3401021
Click on the link to access the technical documentation to attach to your order : DOCACOM_S24
