P12x/EN T/Eb6 - Schneider - error

P12x/EN AP/Eb6Page 68/78Application GuideMiCOM P120/P121/P122/P12327. TRIP CIRCUIT SUPERVISION (P122 & P123 ONLY)The trip circuit extends beyond the relay enclosure and passes through more components,such as fuse, wires, relay contacts, auxiliary switch contact and so on.These complications, coupled with the importance of the circuit, have directed attention to itssupervision.The simplest arrangement for trip circuit supervision contains a healthy trip lamp in serieswith a resistance placed in parallel with a trip output relay contacts of the protection device.However, this solution has limitations as no alarm can be generated. Following paragraphsdescribe typical application examples.27.1 Trip Circuit Supervision mechanismThe Trip Circuit Supervision function included in the MiCOM P122 and P123 relays isdescribed below:WARNING 1:WARNING 2:SINCE HARDWARE 5 (NAMED ALSO PHASE II), THE VALUES USED INTHE CALCULATION OF THE EXTERNAL RESISTOR NEEDED FOR THETRIP CIRCUIT SUPERVISION HAVE CHANGED.THE POLARISATION CURRENT OF THE LOGIC INPUT MUST BE 3.5mADURING 2ms (MINIMUM). THE HOLDING CURRENT AFTER THESE 2msSHOULD BE 2.3mA (SEE P12x/EN TD CHAPTER FOR SPECIFICPOLARISATION RANGES ACCORDING TO NOMINAL RANGE).A logic input is programmed to the AUTOMAT. CTRL/CB Supervision/TC Supervisionfunction. The logic input is associated to the label Trip Circ within the AUTOMAT.CTRL/Inputs menu. Then, this logic input is wired in the trip circuit according to one of thetypical application diagrams shown in the following example.When the function TC Supervision is set to "Yes" under the CB Supervision sub-menu, therelay checks continuously on trip circuit continuity whatever the CB status is CB opened orCB closed. The function TC Supervision is enabled when the trip logic output (RL1) is notenergised. The function TC Supervision is not enabled when the trip logic output (RL1) isenergised.NOTE:If RL1 is energised, the “Trip Circuit Super” alarm message isdisplayed in order to inform that the TC Supervision is not enabled.A 52 Fail (trip circuit failure) signal is generated if the logic input detects no voltage signalduring a time longer than the settable timer tSUP. See Chapter P12x/EN FT (User Guide)and Chapter P12x/EN TD (Technical Data) for the settings.As this function is disabled when the trip logic output (RL1) is energised, this function issuitable for use with the enabled relay latching logic.The tSUP timer can be set according to the following table:MENU TEXTSETTING RANGEMINMAXSTEP SIZETC Supervision ? Yes NotSUP 100ms 10s 50ms