Klockner Moeller Electric Parts from KlocknerMoeller.net

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Electronic motor starters and drives
Frequency inverters DF5, DV5, DF6, DV6

Screening measures

Screening reduces emitted interference (noise immunity of neighbouring systems and devices against external influences). Cables laid between the frequency inverter and the motor must be screened, but the screen must not be considered a replacement for the PE cable. Four-wire motor cables are recommended (three phases plus PE). The screen must be connected to earth (PES) at both ends with a large-area connection. Do not connect the screen with pigtails. Interruptions in the screen, such as terminals, contactors, chokes, etc., must have a low impedance and be bridged with a large contact area.

To do this, sever the screen near the module and establish a large-area contact with earth potential (PES, screen terminal). Free, unscreened cables should not be longer than about 100 mm.

Example: Screen attachment for maintenance switch

Note:
Maintenance switches at of frequency inverter outputs must be operated only at zero current.

Control and signal lines must be twisted and may be double-screened, the inner screen being connected to the voltage source at one end and the outer screen at both ends. The motor cable must be laid separately from the control and signal lines (>10 cm) and must not run parallel to any power cables.