Time-delay overcurrent relay type RIS-1

Time-delay overcurrent relay type RIS-1 
Time-delayed overcurrent relay type RIS-1 is designed to protect against the effects of interruptions of one, two or three phases of parallel connected cables or sheath conductors in a three-phase outgoing 1000 V installation supplied from a system of parallel connected IT3Sb or IT3Sd transformer stations with a capacity of 400kVA and 630kVA and a gear 6/1 kV. It is an overcurrent, delayed, non-adjustable, static relay with a contact output.
The relay is powered through inputs B1-B3. Current signals from star-connected secondary windings of special current transformers are fed to the inputs A0, A1, A2, A3 of the relay.
When one, two or three current transformers flow through the primary windings of a value greater than the setting current of the RIS-1 relay, its electronic system causes a change of the contact state at the B1-B2 and B1-B4 outputs. The relay is completely encapsulated with insulating mass, so it can be installed in the connection chambers of flameproof devices.