Grounding Requirements; Leakage Current (>3.5 Ma) - Danfoss VLT FC 103 Instruction Manual

Installation
Wire Type and Ratings
•
All wiring must comply with local and national
regulations regarding cross-section and ambient
temperature requirements.
2 2
•
Danfoss recommends that all power connections
be made with a minimum 167 °F [75 °C] rated
copper wire.
•
See chapter 10.1 Power-dependent Specifications
for recommended wire sizes.

2.4.2 Grounding Requirements

WARNING
GROUNDING HAZARD!
For operator safety, it is important to ground the
adjustable frequency drive properly in accordance with
national and local electrical codes as well as instructions
contained within this document. Ground currents are
higher than 3.5 mA. Failure to ground the adjustable
frequency drive 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.
14
Instruction Manual
2.4.2.1 Leakage Current (>3.5 mA)
Follow national and local codes regarding protective
grounding of equipment with a leakage current > 3.5 mA.
Adjustable frequency drive technology implies high
frequency switching at high power. This will generate a
leakage current in the ground connection. A fault current
in the adjustable frequency drive at the output power
terminals might contain a DC component which can
charge the filter capacitors and cause a transient ground
current. The ground leakage current depends on various
system configurations including RFI filtering, shielded
motor cables, and adjustable frequency drive power.
EN/IEC61800-5-1 (Power Drive System Product Standard)
requires special care if the leakage current exceeds 3.5 mA.
Grounding must be reinforced in one of the following
ways:
See EN 60364-5-54 § 543.7 for further information.
Danfoss A/S © Rev. 2014-02-10 All rights reserved.
•
Follow all local and national electrical codes to
ground electrical equipment properly
•
Proper protective grounding for equipment with
ground currents higher than 3.5 mA must be
established, see chapter 2.4.2.1 Leakage Current
(>3.5 mA)
•
A dedicated ground wire is required for input
power, motor power and control wiring
•
Use the clamps provided with the equipment for
proper ground connections
•
Do not ground one adjustable frequency drive 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 the motor manufacturer wiring
requirements
•
Ground wire of at least 0.0155 in
•
Two separate ground wires both complying with
the dimensioning rules
2 [10 mm 2 ]
MG16E222