Sigma-II Series SGM*H/SGDH USER'S MANUAL - Esco Drives ...

10 Inspection, Maintenance, and Troubleshooting10.1.7 Troubleshooting for Malfunction without Alarm DisplayTable 10.8 Troubleshooting for Malfunction without Alarm Display (Cont’d)SymptomServomotorRotates WithoutReferenceInputDB (dynamicbrake) DoesNot OperateAbnormalNoise fromServomotorCauseSpeed control: Speed reference inputis incorrect.Torque control: Torque referenceinput is incorrect.Speed reference offset is error.Position control: Reference pulseinput is incorrect.Check V-REF and SG to confirm if the controlmethod and the input are agreed.Check V-REF and SG to confirm if the controlmethod and the input are agreed.The SERVOPACK offset is adjusted incorrectly.Check Pn200.0 reference pulse form or sign+ pulse signal.Correct the control mode selection parameter, or theinput correctly.Correct the control mode selection parameter, or theinput correctly.Adjust the SERVOPACK offset correctly.Correct the control mode selection parameter, or theinput correctly.A SERVOPACK fault occurred. A SERVOPACK board fault occurred. Replace the SERVOPACK.Improper parameter setting Check the setting of parameter Pn001.0. Correct the parameter setting.DB resistor disconnectedCheck if excessive moment of inertia, Replace the SERVOPACK, and reconsider the load.motor overspeed, or DB frequently activatedoccurred.DB drive circuit fault DB circuit parts are faulty. Replace the SERVOPACK.Mounting not securedCheck if there are any loosen mounting Tighten the mounting screws.screws.Check if there are misalignment of couplings.Align the couplings.Check if there are unbalanced couplings. Balance the couplings.Defective bearingsCheck for noise and vibration around the If any problems, contact your Yaskawa representative.bearings.Vibration source on the drivenmachineNoise interference due to incorrectinput signal wire specificationsNoise interference due to long distanceof input signal lineNoise interference due to incorrectencoder cable specificationsNoise interference due to longencoder cable wiring distanceNoise due to damaged encoder cableExcessive noise to the encoder cableFG electrical potential varies byinfluence of such machines on theservomotor side as welders.SERVOPACK pulse counting errordue to noiseExcessive vibration and shock to theencoderInspectionCorrective Actions: Turn OFF the servo system before executing operations.Any foreign matter, damages, or deformationon the machine movable section.The specifications of input signal wiresmust be:Twisted-pair or twisted-pair shielded wirewith core 0.12 mm 2 (0.0002 in 2 ) min. andtinned annealed copper twisted wire.The wiring distance must be 3 m (9.84 ft)max. and the impedance a few hundredsohm max.The specifications of encoder cable mustbe:Twisted-pair or twisted-pair shielded wirewith core 0.12 mm 2 (0.0002 in 2 ) min. andtinned annealed copper twisted wire.The wiring distance must be 20 m(65.6 ft)max.Check if the encoder cable is not damagedor bent.Check if the encoder cable is bundled withhigh-current line or near the high-currentline.Check if the machine is correctly grounded.Check if there is noise interference on thesignal line from encoder.Vibration from the machine occurred or servomotorinstallation is incorrect.(Mounting surface accuracy, fixing, alignment,etc.)Contact the machine manufacturer.Use the specified input signal wires.Shorten the wiring distance for input signal line to thespecified value.Use the specified encoder cable.Shorten the encoder cable wiring distance to the specifiedvalue.Modify the encoder cable layout.Install a surge suppressor to the encoder cable.Encoder fault An encoder fault occurred. Replace the servomotor.Ground the machine separately from PG side FG.Take measure against noise for the encoder wiring.Reduce vibration from the machine, or secure the servomotorinstallation.10-18