Understanding Analog Servo System Module Faults - AB Quality Allen-Bradley 1394 User Manual

9-10 Troubleshooting
Understanding Analog Servo
System Module Faults
Fault Message: Description:
Bus Config
The configured bus
voltage mode does not
match the hardware.
Bus Low Vlt
The DC power bus
activates undervoltage
limit when the bus drops
to 275V DC or less. It
will clear at 300V DC.
Bus Ovr Vlt
The DC Power Bus is
continuously monitored.
If it exceeds a preset
level (810V DC), a fault
is sensed and the power
supply is disabled.
Bus Voltage Operation
Shunt turns on at
800V DC
Shunt turns off at
750V DC
Over voltage trip point
810V DC
Under voltage trip point
275V DC
Under voltage fault
clears at 300V DC
CAN Hdwr SCANport hardware
error detected.
Cntctr Flt
Three-phase power is
either detected when it
shouldn't be or not
detected when it should
be.
Cur Limit
The system module has
reach its current limit.
Publication 1394-5.0 — May 2000
The faults that apply to the Analog Servo System's system module
appear in the following tables.
Note: Although these faults are for the Analog Servo version, in many
instances, the descriptions, causes, and resolutions can also
apply to the GMC version. The fault messages, however, would
be different. Refer to the GML Programming Manual
(publication 999-104) for more information.
Potential cause:
The system module detected an incorrect
shunt module configuration (wrong shunt
installed).
Custom shunt parameters exceed the system
module shunt limits.
The voltage on the 360/480V AC input power
is low.
If this fault occurs when you power up the
system module with the M-contactor, the
power distribution impedance might be stiff or
line voltage might be too high.
The position controller acceleration /
deceleration rate is incorrectly set.
The system inertia is too high causing
excessive energy to be returned to the power
supply bus.
A vertical axis with insufficient
counterbalancing is overdriving the servo
motor and causing excessive energy to be
returned to the power supply bus.
Input line voltage exceeds the maximum input
voltage rating.
Power Driver Board is malfunctioning and is
incorrectly sensing the bus voltage.
The shunt regulator or transistor has
malfunctioned.
External shunt regulator fuse has blown.
The SCANport device or cable is faulty.
The contactor is welded or failed to open.
The input wiring to your contactor is incorrect. Correct wiring.
The motoring/regenerative current produced
by the motor(s) and axis module(s) exceeds
the current limit allowed by the system
module.
Possible resolutions:
• Verify that the shunt module is rated for
and compatible with your system
module.
• Verify custom shunt parameters do not
exceed the system module limitations.
Verify incoming AC voltage and change
the supply source, if needed.
• Perform line conditioning.
• Verify that line voltage is within
specifications.
Change the command profile to reduce
speed or increase time.
• Change the command profile to reduce
speed or increase time.
• Use a larger external shunt resistor.
• Use the external shunt resistor.
• Increase the mechanical
counter-balance on the machine.
Verify incoming 360/480V AC input
voltage and change the supply source, if
needed.
Replace the system module.
Replace the system module.
Check and possibly replace the shunt
resistor.
Check SCANport connections.
• Correct wiring.
• Replace the contactor.
• Increase system module size. The sum
of the axis modules continuous current
exceeds the system module current
limit rating.