Yaskawa LEGEND Digital Torque Amplifier - Manual (Page 58)

4.4 Analog Monitor
47
4.4 Analog Monitor
The following signals can be monitored in the analog voltage form.
The analog monitor output voltage is 8VDC (Max.). The output voltage will invert if it
exceeds 8VDC.
4.5 Regenerative Resistor Selection
When the servomotor is operated in electrical generator mode, the servo amplfier will absorb
electrical power. This is called regenerative power. Although the regenerative power is
absorbed by charging the smoothing capacitor of the digital torque amplifier, the regenerative
power will be further consumed by the regen resistor if the chargeable energy limit of the
capacitor is exceeded. The servomotor is operated in the regen (electrical generator) mode in
the following situations:
• Deceleration to stop time during acceleration/deceleration operation
• Vertical axis load
• Continuous operation where the servomotor continues rotating from the load side
(overhauling load)
The capacity of the regenerative resistor integrated within the digital torque amplifier is
designed for short-term operation only, such as the deceleration to stop period. Operation is
not possible with an overhauling load. Install an external regen resistor if the regen power
exceeds the processing capability of the digital torque amplifier. The specifications of regen
resistors integrated in digital torque amplifiers and the regen power they can process
(average) are shown below.
＊ The regen capacity (average) which can be processed is a 20% rating of the regenerative resistor capacity
integrated within the digital torque amplifier.
When installing an external regen resistor, make the resistance the same as that of the resistor
integrated within the digital torque amplifier. When using several resistors with small
resistance combined in a group to increase the capacity (W) of the regen resistor, select
resistors so that the value including the resistance error is equal to or greater than the
“minimum allowable resistance” in the above table.
1CN Pin No. Signal Name Content
28
Analog Monitor 1 Motor speed
: 1V/1000r/min or 1V/1000mm/sec
29 Analog Monitor 2 Torque = 5V/Max. Torque
Applied Digital Torque
Amplifier
Integrated Regen Resistor
Specifications
Regen Power
Processed by
Integrated
Resistor (W)
Minimum
Total
Resistance
(
Ω) Resistance (
Ω)
Capacity (W)
SGDG-01GT/-04GT － － － 40
SGDG-10GT 50 60 12 40
SGDG-15GT 30 70 14 20