Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 653)

Section 13A
Connecting 8520 Digital Drive Systems
13A-19
For 300% of motor rated current, the following jumpers are open:
- AXIS 1: J5, J6, J11, J12 AXIS 2: J17, J18, J23, J24
- AXIS 3: J29, J30, J35, J36
Table 13A.L
3AX-D Servo Amplifier Jumper Settings (continued)
J37 Short -- Enable Axis 1 Motor
Open -- Disable Axis 1 Motor
J38 Short -- Enable Axis 2 Motor
Open -- Disable Axis 2 Motor
J39 Short -- Enable Axis 3 Motor
Open -- Disable Axis 3 Motor
J40 Short -- Bus Under Voltage FAULT not Latched
Open -- Bus Under Voltage FAULT Latched
J41 Short -- Internal Shunt Resistor Used
Open -- External Shunt Resistor Used
When the servo amplifier is installed as recommended and E-STOP occurs,
the control sets the velocity command to zero. If the axes are in motion at
that time, they will coast to a stop rather than being rapidly decelerated as
they would be under servo amplifier control.
To improve axis stopping time when E-STOP occurs, the 8520 digital
servo amplifier employs a dynamic brake. This brake is in the form of a
power resistor that is shunted across the motor terminals. Power generated
by the motor is dissipated through this resistor, thereby driving the motor
to a rapid stop even though the 8520 digital servo amplifier is off.
There are three shunt resistor options that can be used with the 8520 digital
servo amplifiers. One involves using the internal shunt resistor supplied
with the amplifiers, while the others require purchase and installation of an
external shunt resistor.
The following equations should be used to size a shunt resistor for the
desired application. First, use these equations to solve for the peak power
P, and the average power W. Then apply those values to the chart below to
determine the appropriate shunt option.
P = (.00054) (J) (N
2
)
W = (.0000108) (J) (N
2
)
(T)
13A.6
8520 Digital Servo Amplifier
Shunt Specifications