Grounding - Eaton PowerXL DA1 Series Installation Manual

3.5.2 Grounding

3.5.2.1 Protective earth
3.5.2.2 Motor earthing
3.5.2.3 Earth-fault protection
The protective earth (PE) in the control panel should be connected from the
mains supply to a central earth point (mounting plate, system earth). The PE
conductor's cross-sectional area must be at least as large as that of the
incoming mains supply cable.
Every variable frequency drive must be individually connected to the power
supply system's protective earth directly at the location of installation
(system earthing). This protective earth must not pass through any other
devices.
All protective conductors should be routed in a star topology starting from
the central earth point, and all of the drive's system's conductive
components (e. g., variable frequency drive, sine wave filter) should be
connected.
The earth-fault loop impedance must comply with all locally applicable
industrial safety regulations. In order to meet UL standards, UL-listed ring
cable lugs must be used for all earth wiring connections.
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Avoid ground loops when installing multiple variable frequency
drives in a single control cabinet. Make sure that all metallic
devices that are to be grounded have a broad area connection
with the mounting plate.
This refers to the legally required protective earth for a variable frequency
drive. An earthing terminal on the variable frequency drive, or the system
earth, must be connected to a neighboring steel element in the building
(beam, ceiling joist), an earth electrode in the ground, or a mains earth bus.
The earth points must meet the requirements set forth by the applicable
national and local industrial safety regulations and/or regulations for electrical
systems.
The motor earth must be connected to one of the earthing terminals on the
variable frequency drive and to a neighboring steel element in the building
(beam, ceiling joist), an earth electrode in the ground, or a mains earth bus.
A fault current to earth can be produced by variable frequency drives due to
their system characteristics. DA1 series variable frequency drives have been
designed in such a way that the smallest possible fault current will be
produced in compliance with standards applicable worldwide. In the case of
devices powered with a three-phase supply (DA1-3...), this fault current
must be monitored by a residual current device (RCD, type B).
DA1 Variable Frequency Drives 08/18 MN04020005Z-EN www.eaton.com
3 Installation
3.5 EMC installation
93