• Whenever possible, use the independent earthing (grounding) for the inverter. If independent earthing (grounding) (I) is not available, use (II) common earthing (grounding) in the following figure where the inverter is connected with the other equipment at an earthing (grounding) point. Do not use the other equipment's earthing (grounding) cable to earth (ground) the inverter as shown in (III). A leakage current containing many high frequency components flows into the earthing (grounding) cables of the inverter and peripheral devices. Because of this, the inverter must be earthed (grounded) separately from EMI-sensitive devices.
In a high building, it may be effective to use the EMI prevention type earthing (grounding) connecting to an iron structure frame, and electric shock prevention type earthing (grounding) with the independent earthing (grounding) together. - Earthing (grounding) must conform to the requirements of national and local safety regulations and electrical codes. (NEC section 250, IEC 536 class 1 and other applicable standards). A neutral-point earthed (grounded) power supply must be used to be compliant with EN standard. - Use the thickest possible earthing (grounding) cable. The earthing (grounding) cable should be equal to or longer than the size indicated in the table on page 32 .
- The earthing (grounding) point should be as close as possible to the inverter, and the earth (ground) wire length should be as short as possible. - Run the earthing (grounding) cable as far away as possible from the I/O wiring of equipment sensitive to noises and run them in parallel in the minimum distance. Inverter Other equipment Inverter Other equipment Inverter Other equipment (I) Independent earthing (grounding): B (II) Common earthing (grounding): Good (III) Common earthing (grounding) cable: Not allowed • To be compliant with the EU Directive (Low Voltage Directive), refer to the FREQROL-CS80 Instructions and Cautions for Use of Inverters . 34 2.
INSTALLATION AND WIRING 2.5 Main circuit terminals NOTE