6 Pre-start Check List6.1 Pre-start Check ListMotor• Confirm continuity of the motor by measuring ohm values on U–V (96–97), V–W (97–98), and W–U (98–96).• Confirm that the supply voltage matches the voltage of the drive and the motor.Switches• Ensure that all switch and disconnect settings are in the proper positions.Auxiliary equipment• Look for auxiliary equipment, switches, disconnects, or input fuses/circuit breakers that reside on the input power side of thedrive or output side to the motor. Ensure that they are ready for full-speed operation.• Check function and installation of any sensors used for feedback to the drive.• Remove any power factor correction caps on motor.• Adjust any power factor correction caps on the mains side and ensure that they are dampened.Cable/wire routing• Ensure that motor wiring, brake wiring (if equipped), and control wiring are separated or shielded or in 3 separate metallicconduits for high-frequency interference isolation.Control wiring• Check for broken or damaged wires and loose connections.• Check that control wiring is isolated from high-power wiring for noise immunity.• Check the voltage source of the signals, if necessary.• Use shielded or twisted pair cable.• Ensure that the shield is terminated correctly.Input and output power wiring• Check for loose connections.• Check that motor and mains are in separate conduit or separated shielded cables.Grounding• Make sure that a proper ground is used. Grounding to conduit or mounting the back panel to a metal surface is not a suitablegrounding.• Check for good ground connections that are tight and free of oxidation.Fuses and circuit breakers• Check for proper fusing or circuit breakers.• Check that all fuses are inserted firmly and are in operational condition.• Check that all circuit breakers (if used) are in the open position.Cooling clearance• Look for any obstructions in the airflow path.• Measure top and bottom clearance of the drive to verify that there is at least 225 mm (9 in) of clearance for adequate airflow.Pre-start Check ListOperating Guide | VLT® HVAC Drive FC 102AQ262141314214en-000101 / 130R0880 | 99Danfoss A/S © 2018.10
