Functional block diagram of the S24/T relay
General presentation
The S24/T relay is a multifunction digital protection relay mainly used for the protection of two-winding transformers of any rating or for the protection of generator-transformer units. It consists of two three-phase and earth current units.
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/T relay is a digital differential protection for two-winding transformers and generator-transformer units. Its full set of functionalities allows it to take into account the cable connecting the circuit breaker to the transformer and the back-up protection of the transformer secondary that it protects.
This protection includes various versatile protection functions based on the measurement of the six phase currents and the two residual currents on the primary or secondary side, such as three-phase, residual and unbalance overcurrent protection and thermal overload protection.
This relay also integrates a wide range of control and supervision functions, providing full control and user-defined interlocking schemes for the substation switchgear.
Protection and control functions
- Transformer differential protection function
- Unbalance overcurrent protection function
- Line thermal protection function
- Instantaneous three-phase overcurrent protection function
- Instantaneous residual overcurrent protection function
- Circuit breaker failure protection function
- Time-delayed three-phase overcurrent protection function
- Time-delayed residual overcurrent protection function
- Current unbalance function (current transformer supervision)
- Inrush current detection function
General documentation : Smartline S24 DataSheet – 19AA1121500B
Operation manual : S24T OMA 23AA3401900
Click on the link to access the technical documentation to attach to your order : DOCACOM_S24
