Grounding Requirements; Leakage Current (>3.5 Ma) - Danfoss VLT AutomationDrive FC 302 Operating Instructions Manual

Installation
L1
3 3
L2
L3
2
Item Description
#
1 Fuses
2 Ground
Illustration 3.4 Frequency Converter Fuses
Wire Type and Ratings
•
All wiring must comply with local and national
regulations regarding cross-section and ambient
temperature requirements.
•
Danfoss recommends that all power connections
be made with a minimum 75 °C rated copper
wire.

3.4.2 Grounding Requirements

WARNING
GROUNDING HAZARD!
For operator safety, it is important to ground the
frequency converter properly in accordance with national
and local electrical codes as well as instructions
contained within this document. Do not use conduit
connected to the frequency converter as a replacement
for proper grounding. Ground currents are higher than
3.5 mA. Failure to ground the frequency converter
properly could result in death or serious injury.
NOTICE
It is the responsibility of the user or certified electrical
installer to ensure correct grounding of the equipment in
accordance with national and local electrical codes and
standards.
•
Follow all local and national electrical codes to
ground electrical equipment properly
•
Proper protective earthing for equipment with
ground currents higher than 3.5 mA must be
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Operating Instructions
L1 L2
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Danfoss A/S © Rev. 2014-02-20 All rights reserved.
established, see chapter 3.4.2.1 Leakage Current
(>3.5 mA)
•
A dedicated ground wire is required for input
L3
power, motor power and control wiring
93
•
Use the clamps provided with the equipment for
proper ground connections
•
Do not ground one frequency converter to
another in a "daisy chain" fashion
•
Keep the ground wire connections as short as
possible
•
Using high-strand wire to reduce electrical noise
is recommended
•
Follow motor manufacturer wiring requirements
3.4.2.1 Leakage Current (>3.5 mA)
Follow national and local codes regarding protective
earthing of equipment with a leakage current >3.5 mA.
Frequency converter technology implies high frequency
switching at high power. This will generate a leakage
current in the earth connection. A fault current in the
frequency converter at the output power terminals might
contain a DC component, which can charge the filter
capacitors and cause a transient earth current. The earth
leakage current depends on various system configurations
including RFI filtering, screened motor cables, and
frequency converter power.
EN/IEC61800-5-1 (Power Drive System Product Standard)
requires special care if the leakage current exceeds 3.5 mA.
Earthing (grounding) must be reinforced in one of the
following ways:
•
Earth (ground) wire of at least 10 mm
•
Two separate earth (ground) wires both
complying with the dimensioning rules
See EN 60364-5-54 § 543.7 for further information.
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MG34U302