text: <s>[INST] Help! SMC-3 softstarter Summary: SMC-3 softstarter periodically stops with shorted SCR faultHi guys. Usual belt drive driven by motor-reducer WA 37/T DRS71M4/TF (0,55kW) and powered by SMC-3 (3A ver.) periodically stops with shorted SCR fault (code6). After manual reset it going on work normally. Working mode ~5 stops per minute. Duration of stops is different from 1s to several seconds. SMC configured to soft start with 35% initial moment and starting time 2s w\o kickstart and soft stop. Please give me the physical meaning of shorted SCR and what should I do to avoid this fault. Hope on quick help. Thank you. [/INST] https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/41478/loc/en_US QA5761 12/08/2020 Summary SMC-3 Soft Starter: Causes and Troubleshooting Shorted SCR Question What does it mean when an SMC-3 soft starter flashes six (6) times to indicate a shorted SCR error? How can I verify and what tests can be performed to determine if an SCR is shorted? How can I trouble shoot and clear this fault? Can I over ride this fault? Why does my SMC-3 soft starter trip on Shorted SCR faults? Environment 150-C3NBD, 150-C3NBR, 150-C3NCD, 150-C9NBD, 150-C9NBR, 150-C9NCD, 150-C16NBD, 150-C16NBR, 150-C16NCD, 150-C19NBD, 150-C19NBR, 150-C19NCD, 150-C25NBD, 150-C25NBR, 150-C25NCD, 150-C30NBD, 150-C30NBR, 150-C30NCD, 150-C37NBD, 150-C37NBR, 150-C37NCD, 150-C43NBD, 150-C43NBR, 150-C43NCD, 150-C60NBD, 150-C60NBR, 150-C60NCD, 150-C85NBD, 150-C85NBR, 150-C85NCD, 150-C108NBD, 150-C108NBR, 150-C108NCD, 150-C135NBD, 150-C135NBR, 150-C135NCD, 150-C201NBD, 150-C201NBR, 150-C201NCD, 150-C251NBD, 150-C251NBR, 150-C251NCD, 150-C317NBD, 150-C317NBR, 150-C317NCD, 150-C361NBD, 150-C361NBR, 150-C361NCD, 150-C480NBD, 150-C480NBR, 150-C480NCD Soft Starters Answer Cause Loose 3 phase power connections or damaged conductors on line side of the SMC-3 controller Wire conductor damage on the load side of the SMC-3 controller to the motor Damage to windings inside the motor The SMC-3 control module has sustained physical damage to control circuit board components Power surges, spikes, disturbances, over voltage conditions present in the 3 Phase Power distribution circuits can cause SCR’s to breakdown and short Excessive levels of voltage and current present in the three phase power supply to the SMC-3 soft starter can cause SCR’s to breakdown and short The shorted SCR check is performed internally by the SMC-3 soft starter as a pre start check. A start command will not be issued to the soft starter if a Shorted SCR condition is detected. Note: Shorted SCR Faults cannot be overridden through a parameter change. See the following steps below to troubleshoot and resolve these faults: Verify 3 phase power connections on line side of the SMC-3 controller are tight; correct damage to conductor cables. Verify conductors on load side of the SMC-3 controller going to the motor are tight; correct damage to conductor cables. Verify motor windings are not damaged by meggering the motor. Remove motor leads from the SMC-3 controller before using a Megger to measure and test the motor windings. If the SMC-3 soft starter has the shorted SCR error, perform resistance checks across each of the power poles (L1 to T1, L2 to T2, L3 to T3). The resistance check across all 3-phases should be 10,000 ohms or greater if the SCR is okay and is not shorted. A shorted SCR will have much less resistance than the normal 10,000 ohm reading. Before doing these checks, do the following: Remove the motor leads from the bottom of the SMC-3 soft starter Remove three phase and control power from the SMC-3 soft starter Verify the configuration of dip switch 15 Line Connection is set correctly. Set it to Line for three lead Motors; set it to Delta for six lead Wye Start Delta Motors. Please see Answer ID: Repair Parts for 150-C SMC-3 Smart Motor Controllers to determine the repair part needed to replace the SCRs. \\n </s>