Aerotech Automation1 XC4e, Hardware Manual

Page: 84 / 122

2.8. External Shunt Option [-SX1]
DANGER : The shunt resistor dissipates a high quantity of power. To prevent the danger of
electric shock or fire, you must obey the precautions that follow:
l
Correctly size, mount, and protect the external shunt resistor.
l
Do not touch the shunt resistor terminals. There are lethal voltages on the ter-
minals.
l
Do not touch the surface of the drive or the external shunt resistor. The tem-
perature can exceed 70°C.
l
Restrict access to the shunt resistor while it is connected to a power source.
The -SX1 option provides a connection for a user-provided shunt resistor to dissipate excess energy and
keep the internal drive voltage within safe levels. The drive switches this resistor "ON" when the internal
bus voltage reaches approximately 380 VDC. This option is generally required for systems that have a
large amount of stored mechanical energy that must be dissipated during deceleration.
Table 2-54: -SX1 Component Information
Component Description Aerotech P/N
Recommended Shunt Resistor
50 Ω (min), 300 W
Vishay/Dale: RBEF030050R00KFBVT
ECR01039
1-Pin Mating Connector [QTY. 2]
Screw Torque Value : 0.6 - 0.8 N·m
Wire Size : 0.2 - 6 mm 2 [24-10 AWG]
Phoenix: 0708250
ECK02452
F101 Fuse on the Control Board 8 A S.B. EIF01022
Recommended Wire Size
16 AWG (1.3 mm
2
) High Temperature
--
Equation 1:
Calculate the kinetic energy of the system. Any energy that is not lost to the system could be
regenerated to the DC bus.
or
(for rotary motors) (for linear motors)
J
M
rotor inertia (kg·m 2 )
J
L
load inertia (kg·m
2
)
ω
m
motor speed before deceleration (rad/s)
M
M
forcer mass (kg)
M
L
load mass (kg)
v
m
velocity (m/s)
Equation 2:
You will need a shunt resistor if the regenerated energy is greater than the Maximum Additional Storage
Energy that the internal bus capacitor can store (
Table 2-55 ).
C bus capacitor (F) [1,200 µF]
V
M
turn on voltage for shunt circuit (V) [380 V]
V
NOM
nominal bus voltage (V) [160 V or 320 V, Typical]
[160 V or 320 V, Typical]
2.8. External Shunt Option [-SX1] XC4e Hardware Manual
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