The 7SR11 series of relays provide overcurrent and earth fault protection. These relays are typically applied to provide the main protection on feeders and interconnectors and the back-up protection on items of plant such as transformers. On distribution system circuits overcurrent and earth fault protection is often the only protection installed.
The 7SR12 includes for directional control of the overcurrent and earth fault functionality and is typically installed where fault current can flow in either direction i.e. on interconnected systems.
The relay functionality allows highly flexible settings for current and time grading making it compatible with all types of overcurrent protections.
The relays are available in single and four pole variants housed in E4 cases with the IEC61850 protocol option housed in an E6 case. Integrated logic is provided to allow the optimal configuration of relay functionality with the relays analogue inputs and binary input/output circuits.
Protection, instrumentation and metering functionality is accessible via data comms channel(s). A front USB port for local PC connection or rear electrical RS485 port for remote connection are provided.