13.2.2.2 Start auto-reclosing and conditions for start of a reclosing cycle M12391-94 v4The usual way to start a reclosing cycle, or sequence, is to start it at selective tripping by lineprotection by applying a signal to the input START. Starting signals can be either, General Tripsignals or, only the conditions for Differential, Distance protection Zone 1 and Distanceprotection Aided trip. In some cases also Directional Earth fault function Aided trip can beconnected to start an Auto-Reclose attempt. If general trip is used to start the auto- recloser itis important to block it from other functions that should not start a reclosing sequence.In cases where one wants to differentiate three-phase “auto-reclosing open time”, (“deadtime”) for different power system configuration or at tripping by different protection stages,one can also use the input STARTHS (Start High-Speed Reclosing). When initiating STARTHS,the auto-reclosing open time for three-phase shot 1,t1 3PhHS is used and the closing is donewithout checking the synchrocheck condition.A number of conditions need to be fulfilled for the start to be accepted and a new auto-reclosing cycle to be started. They are linked to dedicated inputs. The inputs are:• CBREADY, CB ready for a reclosing cycle, for example, charged operating gear.• CBPOS to ensure that the CB was closed when the line fault occurred and start wasapplied.• No signal at input INHIBIT that is, no blocking or inhibit signal present. After the start hasbeen accepted, it is latched in and an internal signal “Started” is set. It can be interruptedby certain events, like an “Inhibit” signal.13.2.2.3 Start auto-reclosing from CB open information M12391-100 v5If a user wants to initiate auto-reclosing from the "CB open" position instead of fromprotection trip signals, the function offers such a possibility. This starting mode is selectedwith the setting parameterStartByCBOpen=On. It is then necessary to block reclosing for allmanual trip operations. TypicallyCBAuxContType=NormClosed is also set and a CB auxiliarycontact of type NC (normally closed) is connected to inputs CBPOS and START. When thesignal changes from “CB closed” to “CB open” an auto-reclosing start pulse is generated andlatched in the function, subject to the usual checks. Then the reclosing sequence continues asusual. One needs to connect signals from manual tripping and other functions, which shall notbe reclosed automatically to the input INHIBIT.13.2.2.4 Blocking of the autorecloser M12391-103 v3Auto-Reclose attempts are expected to take place only for faults on the own line. The Auto-Recloser must be blocked by activating the INHIBIT input for the following conditions:• Tripping from Delayed Distance protection zones• Tripping from Back-up protection functions• Tripping from Breaker failure function• Intertrip received from remote end Breaker failure function• Busbar protection trippingDepending of the starting principle (General Trip or only Instantaneous trip) adopted abovethe delayed and back-up zones might not be required. Breaker failure trip local and remotemust however always be connected.13.2.2.5 Control of the auto-reclosing open time for shot 1 M12391-113 v4Up to four different time settings can be used for the first shot, and one extension time. Thereare separate settings for single-, two- and three-phase auto-reclosing open time,t1 1Ph, t12Ph, t1 3Ph. If no particular input signal is applied, and an auto-reclosing program with single-Section 13 1MRK 511 358-UEN AControl242Application manual
