Safety; Emc-Correct Installation - Danfoss vlt aqua Design Manual

5 How to Install

5.10 Safety

5.10.1 High Voltage Test
Carry out a high voltage test by short-circuiting terminals U, V, W, L
drives and 2.525 kV DC for 525–690 V adjustable frequency drives for one second between this short-circuit and the chassis.
NOTE!
When running high voltage tests of the entire installation, interrupt line power and the motor connection if the leakage currents are
too high.
5
5.10.2 Safety Ground Connection
The adjustable frequency drive has a high leakage current and must be grounded appropriately for safety reasons according to EN 50178.
The ground leakage current from the adjustable frequency drive exceeds 3.5 mA. To ensure a good mechanical connection from the
ground cable to the ground connection (terminal 95), the cable cross-section must be at least 0.39 in2 [10 mm2] or 2 rated ground
wires terminated separately.

5.11 EMC-correct Installation

5.11.1 Electrical Installation - EMC Precautions
The following is a guideline for good engineering practice when installing adjustable frequency drives. Follow these guidelines to comply with EN 61800-3
First environment . If the installation is in EN 61800-3
from these guidelines is allowed but not recommended. See also paragraphs
Good engineering practice to ensure EMC-correct electrical installation:
• Use only braided shielded/armored motor cables and braided shielded/armored control cables. The shield should provide a minimum coverage
of 80%. The shield material must be metal, not limited to, but typically, copper, aluminum, steel or lead. There are no special requirements for
the line cable.
• Installations using rigid metal conduits are not required to contain shielded cable, but the motor cable must be installed in conduit separate from
the control and line cables. Full connection of the conduit from the drive to the motor is required. The EMC performance of flexible conduits
varies greatly, and information from the manufacturer must therefore be obtained.
• Connect the shield/armor/conduit to ground at both ends for motor cables as well as for control cables. In some cases, it is not possible to
connect the shield at both ends. If so, connect the shield at the adjustable frequency drive. See also
Control Cables
.
• Avoid terminating the shield/armor with twisted ends (pigtails). It increases the high frequency impedance of the shield, which reduces its
effectiveness at high frequencies. Use low impedance cable clamps or EMC cable connectors instead.
• Avoid using unshielded/unarmored motor or control cables inside cabinets housing the drive(s), whenever this can be avoided.
Leave the shield as close to the connectors as possible.
5-54
, L and L . Energize maximum 2.15 kV DC for 380–500 V adjustable frequency
1 2 3
Second environment, i.e., industrial networks, or in an installation with its own transformer, deviation
CE Labeling, General Aspects of EMC Emission
®
MG.20.N5.22 - VLT is a registered Danfoss trademark
®
VLT AQUA Drive Design Guide
and EMC Test Results .
Grounding of Braided Shielded/Armored