7.5 TroubleshootingSymptom Possible cause Test SolutionDisplaydark/NofunctionMissing input power See Table 4.4. Check the input power source.Missing or open fuses or circuitbreaker trippedSee open fuses and tripped circuit breakerin this table for possible causes.Follow the recommendations provided.No power to the LCP Check the LCP cable for proper connectionor damage.Replace the faulty LCP or connection cable.Shortcut on control voltage(terminal 12 or 50) or at controlterminalsCheck the 24 V control voltage supply forterminals 12/13 to 20-39 or 10 V supply forterminals 50 to 55.Wire the terminals properly.Incompatible LCP (LCP fromVLT® 2800 or 5000/6000/8000/FCD or FCM)Use only LCP 101 (P/N 130B1124) or LCP102 (P/N 130B1107).Wrong contrast setting Press [Status] + [▲]/[▼] to adjust thecontrast.Display (LCP) is defective Test using a different LCP. Replace the faulty LCP or connection cable.Internal voltage supply fault orSMPS is defectiveContact supplier.IntermittentdisplayOverloaded power supply(SMPS) due to improper controlwiring or a fault within theadjustable frequency driveTo rule out a problem in the control wiring,disconnect all control wiring by removingthe terminal blocks.If the display stays lit, then the problem isin the control wiring. Check the wiring forshort circuits or incorrect connections. Ifthe display continues to cut out, follow theprocedure for display dark.Motor notrunningService switch open or missingmotor connectionCheck if the motor is connected and theconnection is not interrupted (by a serviceswitch or other device).Connect the motor and check the serviceswitch.No line power with 24 V DCoption cardIf the display is functioning but no output,check that line power is applied to theadjustable frequency drive.Apply line power to run the unit.LCP Stop Check if [Off] has been pressed. Press [Auto On] or [Hand On] (dependingon operation mode) to run the motor.Missing start signal (Standby) Check 5-10 Terminal 18 Digital Input forcorrect setting for terminal 18 (use defaultsetting).Apply a valid start signal to start themotor.Motor coast signal active(Coasting)Check 5-12 Coast inv. for correct setting forterminal 27 (use default setting).Apply 24 V on terminal 27 or program thisterminal to No operation.Wrong reference signal source Check reference signal: Local, remote or busreference? Preset reference active? Terminalconnection correct? Scaling of terminalscorrect? Reference signal available?Program correct settings. Check3-13 Reference Site. Set preset referenceactive in parameter group 3-1* References.Check for correct wiring. Check scaling ofterminals. Check reference signal.Motor runningin wrongdirectionMotor rotation limit Check that 4-10 Motor Speed Direction isprogrammed correctly.Program correct settings.Active reversing signal Check if a reversing command isprogrammed for the terminal in parametergroup 5-1* Digital inputs.Deactivate reversing signal.Wrong motor phase connection See chapter 5.5 Checking Motor Rotation.Maintenance, Diagnostics an... Instruction ManualMG20MA22 Danfoss A/S © 10/2014 All rights reserved. 497 7