
Unidrive M / HS Frame 7 to 10 Power Installation Guide
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Issue Number: 5
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4.2.1
Supply types
All drives are suitable for use on any supply type i.e TN-S, TN-C-S, TT and IT.
Supplies with voltage up to 600 V may have grounding at any potential, i.e. neutral, centre or corner
(“grounded delta”) Supplies with voltage above 600 V may not have corner grounding
Drives are suitable for use on supplies of installation category III and lower, according to IEC 60664-1.
This means they may be connected permanently to the supply at its origin in a building, but for outdoor
installation additional over-voltage suppression (transient voltage surge suppression) must be
provided to reduce category IV to category III.
A ground fault in the supply has no effect in any case. If the motor must continue to run with a ground
fault in its own circuit then an input isolating transformer must be provided and if an EMC filter is
required it must be located in the primary circuit.
Unusual hazards can occur on ungrounded supplies with more than one source, for example on ships. Contact
the supplier of the drive for more information.
Table 4-2 Behavior of the drive in the event of a ground (earth) fault with an IT supply
* Please note that the internal filter is not removable on size 9E and 10E.
If an SI-Applications Plus module is installed in the drive, then the drive must not be used
on a corner-grounded or centre-grounded delta supply if the supply voltage is above 300
V. If this is required, please contact the supplier of the drive for more information.
Operation with IT (ungrounded) supplies:
Special attention is required when using internal or external EMC filters with ungrounded
supplies, because in the event of a ground (earth) fault in the motor circuit the drive may
not trip and the filter could be over-stressed. In this case, either the filter must not be used
(removed) or additional independent motor ground fault protection must be provided, refer
to Table 4-2 . For details of ground fault protection contact the supplier of the drive.
Drive size
Internal filter only
External filter (with internal)
(All sizes)
May not trip – precautions required:
•
Remove the EMC filter*
•
Use ground leakage relay
May not trip – precautions required:
•
Do not use EMC filter
•
Use ground leakage relay
WARNING
WARNING
Unidrive M frame7 to 10 Power Installation Guide issue5.book Page 55 Tuesday, May 24, 2016 11:52 AM