How to Install Components Correctly|RFI Filters|Supply Cable|Earthing

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The recommended cabling layout for Omron drives and associated components is represented in the diagram below

Installation recommendations for connecting RFI Filters to high frequency inverter drives

Because of the complex circuit design used in these filters an Earth Leakage Current of 8 to 80 mA may be observed. It is possible that nuisance tripping of extremely sensitive types of ELCBs (Earth Leakage Circuit Breakers) may occur so this figure should be considered when choosing such a device.
It is important to provide well defined paths for the high frequency currents involved. By far the best results are achieved when both filter and inverter are mounted securely on the same conducting, earthed backplate and not on rails etc.

Supply Cable
The supply cable should be a stranded conductor and not a solid conductor type to achieve proper connection inside the terminal block, also cable lengths inside the wiring cabinet should be kept to a minimum i.e. cable entry to filter and filter to inverter. This will reduce the effects of radiated emissions back into the input cables.

Motor Cable
Since the cable between the inverter and motor is a major source of radiated and conducted interference, it should be a screened type and as short as possible with the screen and safety earth core connected directly to the bonded earth post at one end and to the motor earth at the other. Never connect only one end of the screen to earth as this can be detrimental - (Pig tail effect). It is strongly recommended that the conducting cores (not the earth or screen) are threaded through or, if possible, wound around an output cable filter choke as shown.

Earthing
The point here is to clearly define the paths through which high frequency earth current flow, and thereby minimise their harmful effect on other nearby, sensitive devices. All earthing leads, including filter earth, inverter earth and screened cable earths, should be as short as possible and securely fastened to the bonded backboard earth post - poor connections and loops of cable will act as aerials and pick up stray radiated emissions.

Separation
Keep the separation of the input and output cables as great as possible to prevent feedback. Input and motor output cables should never be run together in the same trunk or conduit.

Control Cables
The control cables to the inverter or any other equipment in the vicinity are obviously highly susceptible to radiated emissions in the same way and should never be run along side motor output cables.

Multiple Inverters
Where more than one inverter is used, for effective suppression, it is preferable that a separate filter should be used for each inverter.