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Gem6K Hardware Installation Guide
Protective Circuits
Short Circuit Protection
The Gem6K drive has an internal circuit that protects it from short circuits
between one motor terminal to another (phase to phase), or from any motor
terminal to earth. A short circuit fault is a latched fault.
Short circuit fault caused by:
Phase to phase short circuit
Phase to earth short circuit
Results of Fault:
Power to motor is turned OFF
LEDs: Left = illuminated RED; Right = off
Fault output is activated
Latched fault
Inrush Current Protection
The Gem6K drive has internal circuitry that protects it from high inrush current
when power is initially applied to the drive. The circuitry works automatically.
Inrush Current
Current limiter bypassed
Drive
Limiter (ohms):
with shorting relay:
GV6K-L3n
5
Ω
yes
GV6K-U3n
10
Ω
yes
GV6K-U6n
10
Ω
yes
GV6K-U12n
10
Ω
yes
GV6K-H20n
10
Ω
yes
GV6K-H40n
20
Ω
yes
GT6K-L5
5
Ω
yes
GT6K-L8
5
Ω
yes
The shorting relay removes the inrush current limiter after drive startup. This
allows maximum bus voltage during high acceleration/peak torque/maximum
speed applications.
Inrush current is temperature dependent:
Ambient Temperature:
Inrush Current Limit:
25
°
C (77
°
F)
less than 35 amps
50
°
C (122
°
F)
less than 70 amps
50
°
C (122
°
F)
less than 70 amps
Drive Overtemperature Protection
The Gem6K drive’s overtemperature circuit monitors the drive’s internal tempera-
ture sensors. If the sensors exceed the threshold temperature, the drive issues an
overtemperature fault.
Threshold Temperature:
All drives except GV6K-H20n: 80
°
C (176
°
F)
GV6K-H20n:
90
°
C (194
°
F)
Results of Fault:
Power to motor is turned OFF
LEDs: Left = illuminated RED; Right = off
Fault output is activated
Latched fault
Motor Overtemperature Protection – GV6K Servos Only
The GV6K drive has two motor overtemperature circuits:
Hardware Switch:
a thermal switch is embedded in Compumotor motor windings
I
2
t
Thermal Model:
the drive’s internal operating software predicts motor winding
temperature, based on motor current.
