Chapter 3 - Power Connections Insulation Checks Warning! Do not make any voltage tolerance tests (Hi Pot or Meggar) on any part of the ACS 300. Disconnect motor wires from the ACS 300 before making any such tests on the motor or motor wiring. Failure to follow these instructions can result in permanent damage to the ACS 300. Grounding and Ground Faults The ACS 300 must always be grounded through an ground- ing conductor connected to the ground terminal, PE. The grounding conductor should be the same wire size as the input power wires. Metallic conduit is not suitable for use as a grounding conductor. WARNING! Make sure that the drive is securely grounded before applying power.
If the drive is not properly grounded, a dangerous voltage level can develop between the conductive parts of the drive housing and ground due to high leakage current. The ACS 300 ground fault protection guards only the AC drive itself against ground faults occurring in the motor or the motor wiring. It is NOT designed to protect personnel if they come in contact with the motor wiring. Ground fault protective devices do not necessarily operate properly with AC drives. Normally occurring high frequency ground leakage currents can cause nuisance tripping. When using such devices, check their performance while the drive is operating during commissioning.
The ACS 300 should be connected only to a grounded power system. If the power system is ungrounded or grounded through a high resistance, please contact ABB for assistance. ACS 300 User’s Manual 17