Moons' MSST5-S - Page 6

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Rev:5.0
6/08/2010
Rev:5.0
6/08/2010
MSST5/10-S UserManual
MSST5/10-S UserManual
be expected to draw only half the supply current that it would with a 24 volt supply.
To select an appropriate power supply, the following procedure is recommended:
1. If only a few drives will be used, a power supply with a least twice the rated phase current of the
motor is needed.
2. When designing for mass production at low cost, current requirements may rst be determined
by using the power supply recommended above. Install the motor in the application and monitor
the current coming out of the power supply and into the drive at various motor loads. An appropri-
ate power supply can then be selected.
3. If a regulated power supply is used, issues with current fold back may occur. When the drive is
rst powered up, the full current of both motor phases will be drawn for several milliseconds while
the stator eld is being established. The ampliers will then begin chopping and less current will
be drawn. If the power supply reads this initial surge as a short circuit, it may “fold back” to a lower
voltage. Because of this condition, unregulated power supplies are the better option.