61MRS 755535Feeder Protection RelayTechnical Reference Manual - ANSI VersionREF 6101. Introduction1.1. About this manualThis manual provides thorough information on the protection relay REF 610Revision B and its applications. For more information about the earlier revisions,refer to section "Revision history of the REF 610".Refer to the Operator’s Manual for instructions on how to use theHuman-Machine Interface (HMI) of the relay, also known as the Man-MachineInterface (MMI), and to the Installation Manual for installation of the relay.1.2. The use of the relayThe feeder protection relay REF 610 is a versatile multifunction protection relaymainly designed to protect incoming and outgoing feeders in a wide range of feederapplications.REF 610 is based on a microprocessor environment. A self-supervision systemcontinuously monitors the operation of the relay.The HMI includes a Liquid Crystal Display (LCD) which makes the local use of therelay safe and easy.Local control of the relay via serial communication can be carried out with acomputer connected to the front communication port. Remote control can be carriedout via the rear connector connected to the control and monitoring system throughthe serial communication bus.1.3. Features• Three-phase non-directional overcurrent protection with definite-time or IDMT(mode) characteristic, low-set element• Three-phase non-directional overcurrent protection, high-set element• Three-phase non-directional overcurrent protection, instantaneous element• Non-directional ground-fault protection with definite-time or IDMT (mode)characteristic, low-set element• Non-directional ground-fault protection, high-set element• Phase discontinuity protection• Three-phase thermal overload protection for cables• Arc protection• two lens sensors for arc detection (optional)• automatic reference level adjustment based on backlight intensity• arc detection via a remote light signal• Automatic reclosing 1...3 shots• Circuit-breaker failure protection• Trip counters for circuit-breaker condition monitoring• Trip-circuit supervision with possibility to route the warning signal to a non-tripoutput