20bASIc SAFeTy INSTrUcTIONSSwitching at the outputSwitching between motor and drive converter is prohibited for single drives during op-eration as this may trigger the protection gear of the device. Function “speed search”must be activated if switching can not be avoided. Control release may only be triggeredafter closing the motor contactor (e.g. by switching the control release).Connecting and disconnecting is permissible with multiple motor drives if at least 1 mo-tor is running during the switch-over process. The drive converter must be dimensionedto the occurring starting currents.The “speed search” function must be activated if the motor is still running during a restartof the drive converter (mains on) (e.g. due to large rotating masses).Switching on the inputFor applications that require cyclic switching on and off of the drive converter, maintainan off-time of at least 5 min after the last switch on. If you require shorter cycle timesplease contact KEB Automation KG.Short-circuit proofThe drive converters are conditional short-circuit proof. After resetting the internal pro-tection devices, the function as directed is guaranteed.Exceptions:• If an earth-leakage fault or short-circuit often occurs at the output, this can lead to adefect in the unit.• If a short-circuit occurs during regenerative operation (2nd or 4th quadrant, regen-eration into the DC link), this can lead to a defect in the unit.1.6 MaintenanceThe following maintenance work has to be carried out when required, but at least onceper year by authorized and trained personnel.► Check unit for loose screws and plugs and tighten if necessary.► Clean drive converter from dirt and dust deposits. Pay attention especially to cool-ing fins and protective grid of the fans.► Examine and clean extracted air filter and cooling air filter of the control cabinet.► Check the function of the fans of the drive converter. The fan must be replaced incase of audible vibrations or squeaking.► In the case of liquid-cooled drive converters, make a visual leak test of the coolingcircuit for leaks and corrosion must be carried out.
