7SR210 & 7SR220 Description of OperationUnrestricted Page 8 of 94 ©2018 Siemens Protection Devices LimitedSection 1: IntroductionThis manual is applicable to the following relays:· 7SR210 Multi-Function Non-directional Overcurrent and Earth Fault Relay· 7SR220 Multi-Function Directional Overcurrent and Directional Earth Fault RelayThe 7SR210 and 7SR220 relays integrate the protection and control elements required to provide a completeovercurrent based protection.The ‘Ordering Options’ Tables summarise the features available in each model.General Safety Precautions1.1 Current Transformer CircuitsThe secondary circuit of a live CT must not be open circuited. Non-observance of this precaution can result ininjury to personnel or damage to equipment.1.2 External ResistorsWhere external resistors are fitted to the circuit, these may present a danger of electric shock or burns, if touched.1.3 Fibre Optic CommunicationWhere fibre optic communication ports are fitted, the lasers are Class 1 devices but recommend they should notbe viewed directly. Optical power meters should be used to determine the operation or signal level of the device.1.4 Front CoverThe front cover provides additional securing of the relay element within the case. The relay covershould be in place during normal operating conditions.1.5 DisposalThe Relay should be disposed of in a manner which does not provide a threat to health or the environment. Alllaws and regulations specific to the country of disposal should be adhered to.The relays and protection systems manufactured under the Reyrolle brand currently do not come within the scopeof either the European WEEE or RoHS directives as they are equipment making up a fixed installation.!!!!!
