Operating Instructions

Introduction
RFI Jumper
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RFI Jumper
● The drive contains Varistors/MOVs that are connected from phase-to-phase and from phase-to-ground to
prevent the drive from unexpected stop or damage caused by mains surges or voltage spikes. Because the
Varistor/MOVs from phase-to-ground are connected to ground with the RFI jumper, removing the RFI jumper
disables the protection.
● (OEM Only) In models with a built-in EMC filter, the RFI jumper connects the filer capacitors to ground to form a
return path for high frequency noise to isolate the noise from contaminating the mains power. Removing the
RFI jumper strongly reduces the effect of the built-in EMC filter.
● Although a single drive complies with the international standards for leakage current, an installation with several
drives with built-in EMC filters can trigger the RCD. Removing the RFI jumper helps but voids the guaranteed
EMC performance of each drive.
Frames A through F
Screw Torque: 4 to 6 kg-cm/[3.5 to 5.2 lb-in.]/[0.39 to 0.59 Nm]
1. Loosen the screw and remove the RFI jumper. (See below.)
2. Retighten the screw after the RFI jumper is removed.
Fig. 2:
Isolating main power from Ground
When the power distribution system for the drive is a floating ground system (IT Systems) or an asymmetric ground
system (Corner Grounded TN Systems), you must remove the RFI jumper. Removing the RFI jumper disconnects
the internal capacitors from the ground to avoid damaging the internal circuits and to reduce the ground leakage
current.
Important points regarding ground connection
● To ensure the safety of personnel, proper operation, and to reduce electromagnetic radiation, you must
properly ground the motor and drive during installation.
● The diameter of the grounding cables must comply with the local safety regulations.
● You must connect the shielded cable to the motor drive’s ground to meet safety regulations.
● Only use the shielded cable as the Ground for equipment when the aforementioned points are met.
● When installing multiple drives, do not connect the Grounds of the drives in series; connect each drive to
Ground. See below for approved Ground connections.