Hitachi SJ700-2 Series - Manual (Page 29)

2 - 1
OC.Drive
OC.Decel
OC.Accel
Over.C
Over.L
OL.BRD
Over.V
EEPROM
2. Troubleshooting
2.1 Inverter trip contents,remedy,advise
Name Description
Display on
digital operator
Display on
remote operator
Troubleshooting and corrective action
During
constant-
speed
operation
Check whether the load has fluctuated sharply.
(Eliminate the load fluctuation.)
Check for the short circuit of output
connections.
(Check the output cables.)
Check for the ground fault.
(Check the output cables and motor.)
During
deceleration
Check whether the inverter has decelerated the
motor quickly.
(Increase the deceleration time.)
During
acceleration
Check whether the inverter has accelerated the
motor quickly.
(Increase the acceleration time.)
Check whether the motor has been locked.
(Check the motor and wiring.)
Check whether the torque boost current has
been set too high.
(Reduce the boost current.)
Overcurrent
protection
If the motor is constrained
or suddenly accelerated
or decelerated, a high
current will flow in the
inverter and the inverter
may fail. To avoid this
problem, the inverter
shuts off its output and
displays the error code
shown on the right when it
detects a current higher
than a specified level.
This protective function
uses a DC current
detector (CT) to detect
overcurrent.
When a current as high as
about 220% of the
inverter's rated output
current is detected, the
protective circuit operates
and the inverter trips.
Others
Check whether the DC braking force is too high.
(Reduce the braking force.)
Check whether the current detector (CT) is
normal.
(Replace or repair the CT.)
Overload
protection
(*1)
This protective function monitors the
inverter output current, and shuts off the
inverter output and displays the error code
shown on the right when the internal
electronic thermal protection circuit
detects a motor overload.
If the error occurs, the inverter will trip
according to the setting of the electronic
thermal function. Check whether the motor load is too high.
(Reduce the load factor.)
Check whether the thermal level is appropriate.
(Adjust the level appropriately.)
Note:
The electronic thermal protection is easily
triggered when the output frequency is 5 Hz or
less. If the moment of inertia of the load is large,
this protective function may operate when the
inverter accelerates the motor and the
acceleration may be disabled. If this problem
occurs, increase the torque boost current or
adjust other settings as needed.
Braking
resistor
overload
protection
When the BRD operation rate exceeds
the setting of "b090", this protective
function shuts off the inverter output and
displays the error code shown on the
right. Check whether the inverter has decreased the
motor quickly.
(Increase the deceleration time.)
Check whether the operation cycle is too short.
(Prolong the operation cycle.)
Check whether the set BRD operation rate is
too low.
(Adjust the setting to an appropriate level.)
Note: confirm the maximum allowable capacity
of the resistor.
Overvoltage
protection
If the DC voltage across the P and N
terminals rises too high, an inverter failure
may result. To avoid this problem, this
protective function shuts off the inverter
output and displays the error code shown
on the right when the DC voltage across
the P and N terminals exceeds a specified
level because of an increase in the energy
regenerated by the motor or the input
voltage (during operation).
The inverter will trip if the DC voltage
across the P and N terminals exceeds
about 400 VDC (in case of the 200 V class
models) or about 800 VDC (in case of the
400 V class models).
Check whether the inverter has decreased the
motor quickly.
(Increase the deceleration time.)
Check for a ground fault.
(Check the output cables and motor.)
Check whether the motor has been rotated by
the action of the load.
(Reduce the regenerative energy.)
EEPROM
error
(*2) (*3)
When an internal-EEPROM is caused by
external noise or an abnormal
temperature rise, the inverter shuts off its
output and displays the error code shown
on the right.
Note: An EEPROM error may result in a
CPU error. Check for the noise sources located near the
inverter.
(Remove noise sources.)
Check whether the cooling efficiency has
deteriorated.
(Check the heat sink for clogging, and clean it.)
(Replace the cooling fan.)
*1 The inverter will not accept any reset command within about 10 seconds after tripping (i.e., after the protective function operates).
*2 The inverter will not accept any reset command after an EEPROM error occurs with error code displayed. Turn off the
inverter power once. If error code "E08" is displayed when the inverter power is turned on subsequently, the internal memory
device may have failed or parameters may have not been stored correctly. In such cases, initialize the inverter, and then re-set the
parameters.
*3 The inverter will not accept reset commands input via the RS terminal or entered by the STOP/RESET key. Therefore, turn off the
inverter power.