2 Engineering
2.3 Safety and switching
DA1 Variable Frequency Drives
08/18 MN04020005Z-EN
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2.3.4 Residual current device (RCD)
When using variable frequency drives (DA1-3…) that work with a three-
phase power supply (L1, L2, L3), make sure to use type B AC/DC sensitive
residual current devices exclusively.
With a single-phase power supply (L, N) (DA1-12…), you may use type F and
type B residual current devices (RCD).
The leakage currents’ magnitudewill generally depend on:
•
the length of the motor cable,
•
the shielding of the motor cable,
•
the magnitude of the switching frequency (switching frequency of the
inverter),
•
the implementation of the filter measures,
•
the grounding measures at the site of the motor.
Other protective measures against direct and indirect contact can be used for
DA1 variable frequency drives, including isolating them from the supply
system with the use of a transformer.
WARNING
Residual-current devices (RCD) may be installed between the
supply system (AC mains supply) and the DA1 variable frequency
drive only – they must never be installed in the motor output.
