ACH580 Installation, Operation and Maintenance Manual
17
ACH580-01 Installation
Checking the compatibility with IT (ungrounded) and corner-grounded TN systems (North
America)
WARNING!
If the drive will be connected on an IT system (ungrounded or high-
resistance-grounded [over 30 ohms]), make sure that neither the EMC filter nor
the ground-to-phase varistor are connected, that is, the metal screws must not be
installed.
If the drive will be connected on a corner-grounded TN system, make sure that the
EMC filter is not connected, that is, the metal screws must not be installed.
Connections with metal screws in these systems can cause danger or damage.
EMC filter
The AC and DC EMC filters are not suitable for use on an IT (ungrounded) system or
on a corner-grounded TN system. UL (NEC) drives are shipped with a plastic screw
installed to disconnect the internal DC EMC (electro-magnetic compatibility) filter.
Disconnect the AC EMC filter by removing the metal screw before connecting the
drive to the supply network. On symmetrically-grounded TN systems (TN-S) where
EMC is a concern, the installed DC EMC plastic screw can be replaced with the
provided metal screw to connect the filter. See the table on page
. EMC screw
location(s) are labeled on the drive.
Note:
When the internal EMC filter is disconnected, the drive EMC compatibility is
considerably reduced.
