121The heat sink temperature risesabove the permissible limit(see technical data)The external motor temperaturesensor trippedOver temperature reset possibleError over speedThis occurs for a short time dur-ing the power up of the drive, butwill clear automatically if every-thing is OKError signal loss or duringabsolute position search: wrongrotation direction or too muchdragDisplay Description Cause and SolutionInverteroverheatMotor overtemperatureOver temperaturecooled downOver speedDC Buscharging errorEncoder signallossError Messages• Insufficient cooling – increase the airflowaround the inverter• Ambient temperature is too high - add acabinet cooler• Fan is clogged – clean fan• The heatsink temp can be viewed in ru.38• Resistance at the terminals T1/T2 > 1650 Ohm• Motor temperature sensor indicating an over-heated motor• Factory jumper between T1/T2 missing• Internal or external temperature has droppedto a safe level. Error “E.OH“ can be reset.• Speed was greater than 110% of the contractspeed entered in LF.20. Speed is measured bythe motor encoder.• Verify motor data LF.10 – LF.1 and LF.27• If the encoder position in LF.77 is wrong thiserror can occur on starting.• Electrical noise on the encoder cable can alsocause this error.• When driving a PM motor, if parameter LF.14is adjusted too high, E.OS may be triggered atthe beginning of the run.• Input voltage is wrong or to low• Braking resistor connected to the wrong termi-nals or braking transistor is not functioning• Hardware failure –replace inverter• One or more of the signals A+, A-, B+, B-, Z+,Z- are missing.• One or more of the differential signals islatched, i.e. both A+ and A- at are +5V at thesame time. Check the encoder connectionsas well as the signal levels. All + and - signalsshould be opposite ( 0V and >2.0V) while themotor is standing still.• If learning encoder position on a PM motorverify brake is picking fully. Or if the ropes areon try moving the car to a different part of thehoist way. Lastly the PM motor phasing maybe incorrect.
