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Digitax HD M75X Series Installation and Technical Guide
Issue Number: 5
4.2 AC Supply requirements
AC supply voltage:
200 V drive:
200 V to 240 V ±10 %
400 V drive:
380 V to 480 V ±10 %
Number of phases: 1/3
Maximum supply imbalance: 2 % negative phase sequence (equivalent to 3 % voltage imbalance between phases).
Frequency range: 45 to 66 Hz
Table 4-2 Supply fault current used to calculate maximum input currents
4.2.1 Supply types
Drives are suitable for use on the following supply types:
Table 4-3 AC supply configuration suitability
* 400 V corner grounded delta not supported
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.
4.2.2 Line reactors
Input line reactors reduce the risk of damage to the drive resulting from poor phase balance or severe disturbances on the supply network.
Where line reactors are to be used, reactance values of approximately 2 % are recommended. Higher values may be used if necessary, but may
result in a loss of drive output (reduced torque at high speed) because of the voltage drop.
For all drive ratings, 2 % line reactors permit drives to be used with a supply imbalance of up to 3.5 % negative phase sequence (equivalent to 5 %
voltage imbalance between phases).
Severe disturbances may be caused by the following factors, for example:
•
Power factor correction equipment connected close to the drive.
•
Large DC drives having no or inadequate line reactors connected to the supply.
•
Direct-on-line started motor(s) connected to the supply such that when any of these motors are started, the voltage dip exceeds 20 %.
Such disturbances may cause excessive peak currents to flow in the input power circuit of the drive. This may cause nuisance tripping, or in extreme
cases, failure of the drive.
Drives of low power rating may also be susceptible to disturbance when connected to supplies with a high rated capacity.
When required, each drive must have its own reactor(s). Three individual reactors or a single three-phase reactor should be used.
Reactor current ratings
Continuous current:
Not less than the continuous input current rating of the drive
Repetitive peak current:
Not less than three times the continuous input current rating of the drive
Model
Symmetrical fault level (kA)
All
100 kA
AC supply configuration
Supply type
230 V
400 V
Star (Y) connected supply
Any TN, TT or neutral grounded
Permitted
Permitted
IT (floating supply)
Permitted
Permitted
Corner grounded
Not permitted
Not permitted
Corner grounded in regen mode
Not permitted
Not permitted
Delta connected supply
Any TN, TT or neutral grounded
Permitted
Not permitted*
IT (floating supply)
Permitted
Not permitted
Centre of one side of delta grounded
Not permitted
Not permitted
Corner grounded in regen mode
Not permitted
Not permitted
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 4-3. For instructions on removal, refer to
section 4.10.3
on page 65. For details of ground fault protection contact the supplier of the drive.
WARNING
Summary of Contents for Digitax HD M75 Series
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