Earthing; Extra Protection (Rcd); Drives With Factory Installed A1/B1 Rfi Filter Option; Torque - GE AF-600 FP Operating Instructions Manual

3.1.2 Earthing

The following basic issues need to be considered when installing a frequency converter, so as to obtain electromagnetic compatibility (EMC).
• Safety earthing: Please note that the frequency converter has a high leakage current and must be earthed appropriately for safety reasons. Apply local
safety regulations.
• High-frequency earthing: Keep the earth wire connections as short as possible.
Connect the different earth systems at the lowest possible conductor impedance. The lowest possible conductor impedance is obtained by keeping the conductor
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as short as possible and by using the greatest possible surface area.
The metal cabinets of the different devices are mounted on the cabinet rear plate using the lowest possible HF impedance. This avoids having different HF voltages
for the individual devices and avoids the risk of radio interference currents running in connection cables that may be used between the devices. The radio
interference will have been reduced.
In order to obtain a low HF impedance, use the fastening bolts of the devices as HF connection to the rear plate. It is necessary to remove insulating paint or
similar from the fastening points.

3.1.3 Extra Protection (RCD)

ELCB relays, multiple protective earthing or earthing can be used as extra protection, provided that local safety regulations are complied with.
In the case of an earth fault, a DC component may develop in the fault current.
If ELCB relays are used, local regulations must be observed. Relays must be suitable for protection of 3-phase equipment with a bridge rectifier and for a brief
discharge on power-up.
See also the section Special Conditions in the Design Guide.

3.1.4 Drives with factory installed A1/B1 RFI Filter option:

Mains supply isolated from earth
If the frequency converter is supplied from an isolated mains source ( IT mains, floating delta and grounded delta) or TT/TN-S mains with grounded leg, the RFI
switch is recommended to be turned off (OFF)
motors are connected or the motor cable length is above 25 m, it is recommended to set par. SP-50 RFI Filter to [ON].
1)
Not available for 525-600 V frequency converters.
In OFF, the internal RFI capacities (filter capacitors) between the chassis and the intermediate circuit are cut off to avoid damage to the intermediate circuit and
to reduce the earth capacity currents (according to IEC 61800-3).
It is important to use isolation monitors that are capable for use together with power electronics (IEC 61557-8).

3.1.5 Torque

When tightening all electrical connections it is very important to tighten with
the correct torque. Too low or too high torque results in a bad electrical con-
nection. Use a torque wrench to ensure correct torque
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1)
via par. SP-50 RFI Filter. For further reference, see IEC 364-3. In case optimum EMC performance is needed, parallel
AF-600 FP High Power Operating Instructions
Illustration 3.14: Always use a torque wrench to tighten the bolts.