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Siemens delivers high-performance with dual powered protection relay

Reyrolle 7SR46 protection relay

Due to their often remote location, secondary substations do not always have a battery to provide power to electronic equipment such as protection relays. With this in mind, the 7SR46 has been designed to operate using power from current transformers (CTs) when the line is live. Addressing scenarios whereby the line is switched off and there is already a fault on the line, or the earth connection has been mistakenly left connected, the 7SR46 has been specifically designed to power up quickly to provide protection in such circumstances.
Providing additional flexibility and security, the 7SR46 is dual powered to allow a connection to an auxiliary battery supply. With power available from the current transformers and an auxiliary power supply, this feature provides redundancy in case the battery fails. 
The 7SR46 device has a compact (H104 mm x W185 mm x D79 mm), moulded enclosure. The front of the device includes an easy-to-use display and push buttons that can be used to programme the relay and view fault records and instrumentation. Four LEDs provide information on the relay’s status and a mechanical trip flag is also available. The front of the device features a USB communication port for connecting to a PC and can power the relay when no other power source is available. The USB port also allows plug and play connection to Reydisp to programme the device and download fault and event information. The integrated battery allows users to program the device and to download event and fault records without a connected power supply. The rear of the device features user-friendly detachable terminals for RS485 communication interface (Modbus RTU and IEC 60870-103), auxiliary power supply, binary inputs, binary outputs, external trip initiation input, external flag output and a pulse output. The CTs (of type 5P80) are connected with a secure ring crimp. A clear connection diagram is also located on the rear of the relay to aid the user.
Adhering to stringent product testing standards, the 7SR46 is perfectly suited for use in distribution transformer stations where there is not a circuit breaker trip supply. The device features a pulse output that can activate a low power trip coil to trip the circuit breaker. Available at a highly competitive price point, the 7SR46 provides comprehensive and reliable protection for medium voltage applications.
For further information on Siemens Smart Infrastructure, please see
For further information on the Reyrolle 7SR46, please see

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Siemens Smart Infrastructure (SI) is shaping the market for intelligent, adaptive infrastructure for today and the future. It addresses the pressing challenges of urbanization and climate change by connecting energy systems, buildings and industries. SI provides customers with a comprehensive end-to-end portfolio from a single source – with products, systems, solutions and services from the point of power generation all the way to consumption. With an increasingly digitalized ecosystem, it helps customers thrive and communities progress while contributing toward protecting the planet. Siemens Smart Infrastructure has its global headquarters in Zug, Switzerland. As of September 30, 2021, the business had around 70,400 employees worldwide.
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Siemens AG (Berlin and Munich) is a technology company focused on industry, infrastructure, transport, and healthcare. From more resource-efficient factories, resilient supply chains, and smarter buildings and grids, to cleaner and more comfortable transportation as well as advanced healthcare, the company creates technology with purpose adding real value for customers. By combining the real and the digital worlds, Siemens empowers its customers to transform their industries and markets, helping them to transform the everyday for billions of people. Siemens also owns a majority stake in the publicly listed company Siemens Healthineers, a globally leading medical technology provider shaping the future of healthcare. In addition, Siemens holds a minority stake in Siemens Energy, a global leader in the transmission and generation of electrical power.
In fiscal 2022, which ended on September 30, 2022, the Siemens Group generated revenue of €72.0 billion and net income of €4.4 billion. As of September 30, 2022, the company had around 311,000 employees worldwide. Further information is available on the Internet at
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Jessica Humphrey

Smart Infrastructure

+44 7921 728517