Toshiba TOSVERT VF-A7 Instruction Manual page 244

(Continued from the preceding page)
Contents
Indication
Over-voltage
 during fixed
speed
Inverter

overloaded
Motor

overloaded
Dynamic braking

resistor overload
Overheat

Emergency

stop
EEPROM error

Initial read-error

Initial read-error

Main RAM fault

Main ROM fault

CPU fault

Interruption
communication

fault
Gate array

fault
Output current

detector error
Optional unit

fault
Flush memory

fault
low-current
(*1)
operation
(Continued on the following page)
Expected causes
Input voltage abnormally varied.
1 Power capacity is 500 kVA or
more.
2 Power-factor improving
capacitor was turned on/off.
3 Some unit using thyrister is
connected with the same
power supply line.
Motor falls into regeneration status
because it is rotated fast
exceeding inverter's output
frequency by power of loaded
side.
Rapid acceleration is operated.
DC breaking rate is too high.
V/f parameter is improperly set.
Running motor is started during
momentary power failure status
or so.
Load is too heavy.
V/f parameter is improperly set.
Motor is locked.
Continuous operation in low
speed range.
Motor is operated with overload.
Rapid deceleration is operated.
Dynamic braking rate is too high.
Set over-voltage limit operation
revel parameter  too small.
Cooling fan is not actuated.
Ambient temperature is too high.
Vent of cooling fan is shut.
Some heat generating matter is
located nearby.
Internal thermistor of unit is
disconnected.
Inverter is stopped by panel operation
during automatic or remote operation.
Error occurs during writing data.
Something abnormal in internal data.
Something abnormal in internal data.
Something abnormal in control RAM.
Something abnormal in control ROM.
Something abnormal in control CPU.
Something abnormal occurred
during communication operation.
Main gate array is abnormal.
Main output current detector is
abnormal.
Something abnormal occurred in
some optional unit (including
abnormal communication [optional
add-on cassettes]).
Something abnormal in flush
memory.
Output current declined to the
low-current detection level during
operation.
L-2
Countermeasures
Try to insert input reactor.
Install dynamic braking resistor.
Extend acceleration time #1 .
Decrease values of DC injection
braking current  and DC
injection braking time .
Check V/f parameter.
Use  (Auto-restart) and 
(Regenerative power ride-through control).
Raise rating of the inverter.
Check V/f parameter.
Check loading unit.
Reset  properly to motor's
overload reduction start-up
frequency.
Extend deceleration time #1 .
Increase capacity (wattage) of
dynamic braking resistor and reset
the PBR capacity parameter .
Increase the setting value of .
After cooling down inverter, reset it
from failure and try to restart it.
If cooling fan does not work in
operation, it needs replacement.
Secure spaces in the periphery of the
inverter.
Don't locate any heat generating thing
near the inverter.
Make a service call.
Reset the inverter.
Again turn on the inverter. If it is not
reset, make a service call.
Make a service call.
Make a service call.
Make a service call.
Make a service call.
Make a service call.
Check communication units and their
connections.
Make a service call.
Make a service call.
Check connection of optional
board(s).
Refer to instructions of options
concerned.
Make a service call.
Check to see if low-current detection
level is set properly to the system or
not ().
If low-current detection level is
properly set, make a service call.