Sepam - HV/MV Protection and control units (ENG) - Trinet

Logic discriminationUseOperating principleThis function is used to obtain:c full tripping discrimination,c a substantial reduction in delayed tripping of thecircuit breakers located nearest to the source(drawback of the classical time-based discriminationfunction).This system applies to the definite time (DT) and IDMT(standard inverse time SIT, very inverse time VIT,extremely inverse time EIT and ultra inverse time UIT)phase overcurrent and earth fault protections.level "n + 1"SepamBI transmissionO14outputs O14otherlevel "n"Sepamslevel "n"SepamI12-+O14I12td: X+0.9 sBI receipttd: X+0.6 sRadial distribution with use of time-based discrimination(td: tripping time, definite time curves).td: Xstd: X+0.3 std: Xstd: X sWhen a fault occurs in a radial network, the fault current flows through the circuitbetween the source and the location of the fault:c the protections upstream from the fault are triggered,c the protections downstream from the fault are not triggered,c only the first protection upstream from the fault should trip.Each Sepam 2000 is capable of transmitting and receiving blocking input (BI) ordersexcept for motor and capacitor Sepams which can only transmit blocking inputorders.When a Sepam 2000 is triggered by a fault current:c It transmits a blocking input order from output O14,c It trips the associated circuit breaker if it does not receive a blocking input order oninput I12.Transmission of the blocking input lasts for the time required to clear the fault. It isinterrupted after a time delay that takes into account the breaking device operatingtime and the protection returning time.Sepam 2000 includes several phase overcurrent and earth fault protection itemswhich provide multi-level protection (low set, high set,...).All the items (set points 1 to 4)* are capable of transmitting blocking inputs.The 2 items, set points 1 and 2, do not involve the receipt of a blocking input orderand are designed for use with time-based discrimination.The 2 items, set points 3 and 4, involve the receipt of a blocking input and providefast selective operation.This system makes it possible to minimize the duration of the fault, optimizediscrimination and guarantee safety in downgraded situations(wiring or switchgear failures).td: Xs(*) Motor and capacitor Sepam 2000 include two items (set points 1 and 2).They do not involve the receipt of blocking inputs since they are designed for loads.Bl ordertd: XsRadial distribution with use of the Sepam 2000 logicdiscrimination system.With this type of system, the time delays should be setwith respect to the element to be protected withoutconsidering the discrimination aspect.1/16 Control and monitoring functions