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4.3 Troubleshooting
4.3.1 List of Protective Functions
When the protective function is activated, check the ON / OFF state of the transistor output (Y2 - Y4), based on the table
below, identify the protective function that worked. For information about how to deal with each protection function, please
refer to section 4.3.2.
Table 4.3-1 List of protective functions
transistor output
Num.
Name Description
Y4 Y3 Y2
[1]
Overcurrent
This function is activated if the current to the external braking resistor
exceeds the overcurrent level of the dynamic breaking unit.
OFF OFF ON
[2]
Overvoltage
This function is activated if the DC link bus voltage exceeds the overvoltage
detection level (1230 VDC) due to an increase of supply voltage or
regenerative braking current from the motor.
Note that the dynamic breaking unit cannot be protected from excessive voltage
(high voltage, for example) supplied by mistake.
OFF ON OFF
[3]
DC fuse blown
If a fuse in the main DC circuit blows to open the microswitch of the fuse due
to a short circuit in the IGBT circuit, then this protective function displays the
error to prevent the secondary damage. The dynamic breaking unit could be
broken, so immediately contact your Fuji Electric representative.
ON OFF OFF
[4]
Memory error This function is activated when a memory error such as a data write error occurs.
[5]
CPU error
This function is activated if a CPU error occurs.
[6]
Hardware error
Upon detection of an LSI failure on the printed circuit board, this function is
activated
ON OFF ON
[7]
Heat sink
overheat
This function is activated if the temperature surrounding the heat sink (that
cools down the IGBTs) increases due to stopped cooling fans.
[8]
Dynamic
breaking unit
internal
overheat
This function is activated if the temperature surrounding the control printed
circuit board increases due to poor ventilation inside the dynamic breaking
unit.
ON ON OFF
[9]
Inter-
dynamic
breaking unit
communicatio
ns link error
This function is activated if a communications error occurs in the
dynamic
breaking unit
-
to
-
dynamic breaking unit
communications link using a
high-speed serial communication terminal block (option).
ON ON ON
Notes
• All protective functions are automatically reset if the control power voltage decreases until the dynamic breaking
unit control circuit no longer operates.
• Stoppage due to a protective function can be reset by turning OFF and then ON between the X2 terminal (
Reset
alarm)
and the CM. This action is invalid if the cause of an alarm is not removed.
• The dynamic breaking unit cannot reset until the causes of all alarms are removed.
4.3.2 Possible causes of alarms, checks and measures
[ 1 ] Overcurrent
Problem The momentary current of the external braking resistor exceeded the overcurrent level.
Possible Causes
What to Check and Suggested Measures
(1) Connection of the external
braking resistor is wrong.
The external braking resistor
connecting terminal lines were
short-circuited or ground
faults.
Check three sets of external braking resistor is being connected properly in DB1,
DB2, and DB3 terminal between DC link bus N bars.
Correct the connection.
(2) Resistance of the external
braking resistor is too small.
Remove the wiring from (DB1, DB2, DB3) external braking resistor connection, it
is confirmed that the resistance of the external braking resistor is greater than the
minimum connectable resistance.
Connect the external braking resistor suitable.
Summary of Contents for BUC S-69D
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