LV generator protection - engineering site - Schneider Electric

STR23SE (U y 525 V) and STR23SV (U > 525 V)electronic trip unitsE887346 1 73test+-.7.63.5Io.8 .91x InSTR 23 SEIr.9 .93.88 .95.85 .98.8 1x Ioalarm43290105 %IrIsd5 6x Ir7810IrIsdE88735t123450 Ir Im1 long-time threshold (overload protection)2 long-time tripping delay3 short-time pick-up (short-circuit protection)4 short-time tripping delay5 instantaneous pick-up (short-circuit protection)6 test connector7 percent load indication.ProtectionIThe protection functions may be set using the adjustment dials.Overload protectionLong-time protection with an adjustable threshold and fixed tripping delay:b Io base setting (6-position dial from 0.5 to 1)b Ir fine adjustment (8-position dial from 0.8 to 1).Short-circuit protectionShort-time and instantaneous protection:b short-time protection with an adjustable pick-up and fixed tripping delayb instantaneous protection with fixed pick-up.Protection of the fourth poleOn four-pole circuit breakers, neutral protection is set using a three-positionswitch to 4P 3d (neutral unprotected), 4P 3d + N/2 (neutral protection at 0.5 In) or4P 4d (neutral protection at In).IndicationsA LED on the front indicates the percent load:b ON - load is > 90 % of Ir settingb flashing - load is > 105 % of Ir setting.TestA mini test kit or a portable test kit may be connected to the test connector on thefront to check circuit-breaker operation after installing the trip unit or accessories.53