Appendix A – Specifications
85
Undervoltage Protection
The Gem6K drive’s undervoltage protection circuit monitors AC input voltage. If
the voltage falls below 75VAC while the drive is operating (85VAC for GV6K-
H20), the drive issues an undervoltage fault and turns off power to the motor.
Undervoltage protection has the following features:
Threshold Voltage:
Voltage falling below 75VAC trips fault
(85VAC for GV6K-H20n)
Results of Fault:
Power to motor is turned OFF
LEDs: Left = illuminated RED; Right = off
Fault output is activated
Latched fault
Overvoltage Protection – GV6K Servos Only
The GV6K drive’s overvoltage circuit protects the drive from excessive regenera-
tion. If the voltage on the motor output terminals rises above the threshold voltage,
the drive disables its output terminals, and the motor will freewheel.
Threshold Voltage:
GV6K-L3n:
212VDC
GV6K-U3n/6n/12n/H20n/H40n: 410VDC
Results of Fault:
Power to motor is turned OFF
LEDs: Left = illuminated RED; Right = off
Fault output is activated
Latched fault
CAUTION
Overvoltage protection monitors only the motor output terminals (DC motor bus). It
does not protect against an overvoltage on the AC input terminals.
Current Foldback – GV6K Servos Only
The GV6K drive’s current foldback circuit helps to protect the motor from damage
due to prolonged high currents.
If your drive is operating above its continuous rating, use the figure below to
predict the number of seconds until foldback will occur. For example, the figure
shows that at the drive’s peak current rating (250% of continuous), foldback will
occur after six seconds.
1
10
100
10
3
10 4
0
Peak Rating = 250 %
150 %
200 %
Continuous Rating = 100 %
50 %
Time (seconds)
Drive Current Rating vs. Time
Time Until Foldback
See
Chapter 3 Configuration
for more information on how to configure the current
foldback circuit to protect your motor.
