Earthing - Eaton PowerXL DC1 20 Series Installation Manual

3 Installation
3.5 EMC installation

3.5.2 Earthing

3.5.2.1 Protective earth
3.5.2.2 Motor earthing
3.5.2.3 Earth-fault protection
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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. For mobile equipment, the cross-section of the
PE conductor must be at least 10 mm
3.5 mA.
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 magnet system's conductive
components (e.g. variable frequency drive, sine filter) should be connected.
The earth-fault loop impedance must comply with all locally applicable
industrial safety regulations. In order to meet UL requirements, UL-listed ring
cable lugs must be used for all earth wiring connections.
￫
Avoid ground loops when installing multiple variable frequency
drives in one control panel. 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 earthing must be connected to one of the earthing terminals on
the variable frequency drive, as well as to the central earth point on the
power drive system (PDS). Earth connections to a neighboring steel element
in the building (e.g., beam, ceiling joist), a ground rod in the ground, or a
mains earth bus must meet the requirements set forth in the applicable
national and regional industrial safety regulations and/or regulations for
electrical systems.
A fault current to earth can be produced by variable frequency drives due to
their system characteristics. DC1 series variable frequency drives have been
designed in such a way that the smallest possible fault current will be
DC1...20... and DC1...OE1 Variable Frequency Drives 02/20 MN040059EN www.eaton.com
2
for leakage currents greater than