SMAC
LAC-26 Technical Reference Manual
4/29/2013 70
filter card is necessary.
A minimum motor inductance rating for each specific DZ drive can be found in the drive datasheet. If the
drive is operated below the maximum rated voltage, the minimum load inductance requirement may be
reduced.
5.4.3 Power Supply Specifications
DZ servo drives operate off an isolated unregulated DC Power Supply (see Table 2.2 for drive model
power supply ranges and over-voltage shutdown values). To avoid nuisance over- or under-voltage errors
caused by fluctuations in the power supply, the system power supply voltage should be at least 10% above
the entire system voltage requirement, and at least 10% below the lowest value of the following:
•
Drive over voltage
•
External shunt regulator turn-on voltage
Use of a shunt regulator is necessary in systems where motor deceleration or a downward motion of the
motor load will cause the system’s mechanical energy to be regenerated via the drive back onto the power
supply. This regenerated energy can charge the power supply capacitors to levels above that of the DZ
drive over - voltage shutdown level. If the power supply capacitance is unable to handle this excess
energy, or if it is impractical to supply enough capacitance, then an external shunt regulator must be used
to dissipate the regenerated energy. The shunt regulator will "turn-on" at a certain voltage level (set below
the drive over-voltage shutdown level) and discharge the regenerated electric energy in the form of heat.
The diagram below provides a possible example of an appropriate system power supply voltage for a DZ-
012L080 drive using an external shunt regulator.
FIGURE 2.6
Sample DZ-012L080 Power Supply Selection
100
DZ Drive Over Voltage Shutdown (88V)
80
Shunt Regulator Turn-On Voltage (80V)
60
Acceptable Power Supply
VDC
40
Range (26V-72V)
System Power Supply Requirement (24V)
20
DZ Drive Under Voltage Shutdown (17V)
0
