Rockwell Automation 2090-UCSR-A300 300 W Active Shunt Regulator - Manual (Page 11)

Publication 2090-IN002C-EN-P — June 2007
300 W Active Shunt Regulator 11
Troubleshoot
If this fault appears Then
Overtemp light is on
The internal thermostat in the shunt unit is
getting too hot. To fix this problem:
•
reduce the average shunt power,
• reduce the ambient temperature of the air
around the shunt, or
•
increase the amount of air passing over the
heat-sink fins.
Once this LED turns on, only removing power will
shut it off; even when the active shunt unit has
cooled and is functioning again.
Drive registers Bus Overvoltage faults, but the
active shunt is functioning and the Overtemp light
is off.
There are two situations where this can happen.
•
First, if the Bus Overvoltage trip level on the
drive is too low. Since this is not adjustable
on the drive, the solution is to reduce the
turn-on threshold level of the active shunt.
This is done by turning the Adjust pot
counter-clockwise.
• Second, if the regeneration power exceeds
the shunt power for too long. It is possible
for the drive to generate more power than
the active shunt can handle. There are two
possible solutions to this situation.
•
Adjust the regeneration profile so that
the drive generates less power for a
longer time. The drive current limit
parameters may be useful here.
• Reduce the turn-on threshold level of
the active shunt, which turns on the
shunt earlier in the regeneration
profile.
Adjust
Overtemp
DC Bus
Active
Active Shunt