3 Installation
3.4 Correct EMC installation
DB1 variable frequency drive
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Eaton.com
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3.4.2.2 Motor grounding
The motor grounding must be connected to one of the grounding terminals
on the variable frequency drive, as well as to the central ground point on the
power drive system (PDS). Ground connections to a neighboring steel ele-
ment in the building (e.g., beam, ceiling joist), a ground rod in the ground, or
a mains ground bus must meet the requirements set out in the applicable
national and regional industrial safety regulations and/or regulations for elec-
trical systems.
3.4.2.3 Earth-fault protection
With a variable frequency drive, a fault current to ground can occur due to the
system.
DB1 series variable frequency drives have been designed in such a way that
the smallest possible fault current will be produced in compliance with stan-
dards applicable worldwide. In the case of devices powered with a three-
phase supply (DB1-3…), this fault current must be monitored by an AC/DC-
sensitive type B residual current device (RCD).
3.4.2.4 EMC screw
Due to their system characteristics, variable frequency drives with an internal
EMC filter will produce a larger fault current to ground than devices without a
filter. For applications in which this larger leakage current may cause mal-
function messages or disconnections (residual current device), the EMC fil-
ter’s internal protective ground can be disconnected (remove the EMC screw
to do this). Local EMC regulations must be taken into account when doing
so. If necessary, a specific low-leakage-current EMC filter (DX-EMC...-L)
must be connected upstream. In connections to isolated power sources
(IT networks), the EMC screw should be removed. The ground fault monitors
required for IT networks must be suitable for operation with power electronic
devices (IEC 61557-8).
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The EMC screw galvanically connects the EMC filter’s mains-
side capacitors to the ground connection (PE).
The EMC screw must be screwed in all the way to the stop
(default setting) in order for the variable frequency drive to
comply with EMC standards.
WARNING
The screw labeled EMC must not be manipulated as long as the
variable frequency drive is connected to the mains or there is a
DC link voltage.
￫
The location of the EMC screw in the respective frame size can
be found in
