Networks - WEG CFW-11 User Manual

3.2.3.1.2 IT Networks
ATTENTION!
Do not use inverters with internal RFI filters in IT networks (neutral is not grounded or grounding
provided by a high ohm value resistor) or in grounded delta networks ("delta corner earth"), because
these type of networks damage the inverter filter capacitors.
The CFW-11 inverter series, except the models with internal RFI filters – CFW11XXXXXXOFA, can be normally
used in IT networks. If the available model is equipped with an internal filter, remove the two grounding screws
from the filter capacitors as presented in
to have access to these screws in frame sizes A, B, and C. For frame size D, the bottom front cover shall be
removed as well.
Consider the following items for the use of protection devices on the supply side of the inverter such as residual
current devices or isolation monitors:
- The detection of a phase-to-ground short-circuit or an insulation fault shall be processed by the user, i.e., the
user shall decide whether to indicate the fault and/or block the inverter operation.
- Contact the RCD manufacturer for selecting the most appropriate device to be used with inverters in order to
avoid nuisance tripping due to the high frequency leakage currents that flow through the leakage capacitances
of the inverter, cable, and motor system to the ground.
XE1
(a) Frame size A - IP2X or Nema1
XE1
(c) Frame size C - IP2X or Nema1
Figure 3.12 on page 3-20. Remove the keypad and the front cover
XE2
XE1
(b) Frame size B - IP2X or Nema1
XE2
XE1
(d) Frame size D - IP2X or Nema1
Installation and Connection
XE2
XE2
CFW-11 | 3-19
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