Mitsubishi Electric FR-D720 K Series Instruction Manual page 265

Operation panel
SA
indication
Name Safety stop
Description Appears when safety stop function is activated (during output shutoff). (Refer to page 27.)
Check if the shorting wire between S1 and SC or between S2 and SC is disconnected when not using the safety stop
Check point
function.
 When not using the safety stop function, short across terminals S1 and SC and across S2 and SC with shorting
wire for the inverter to run.
Corrective action
 If "
function (drive enabled), internal failure might be the cause. Check the wiring of terminals S1, S2 and SC and
contact your sales representative if the wiring has no fault.
(3) Alarm
When an alarm occurs, the output is not shut off. You can also output an alarm signal by making parameter setting.
(Set "98" in Pr. 190, Pr. 192 or Pr. 197 (output terminal function selection). Refer to page 122.)
Operation panel
FN
indication
Name
Fan alarm
For the inverter that contains a cooling fan, "
Description
an alarm or different operation from the setting of Pr. 244 Cooling fan operation selection.
Check point Check the cooling fan for an alarm.
Corrective action Check for fan alarm. Please contact your sales representative.
(4) Fault
When a fault occurs, the inverter output is shut off and a fault signal is output.
Operation panel
E.OC1
indication
Name Overcurrent trip during acceleration
When the inverter output current reaches or exceeds approximately 200% of the rated current during acceleration, the
Description
protective circuit is activated and the inverter output is shut off.
 Check for sudden acceleration.
 Check that the downward acceleration time is not long for the lift.
 Check for output short-circuit/ground fault.
 Check that the Pr. 3 Base frequency setting is not 60Hz when the motor rated frequency is 50Hz.
Check point
 Check if the stall prevention operation level is set too high.
Check if the fast-response current limit operation is disabled.
 Check that regeneration is not performed frequently. (Check that the output voltage becomes larger than the V/F
reference value at regeneration and overcurrent occurs due to increase in motor current.)
 Increase the acceleration time. (Shorten the downward acceleration time for the lift.)
 When "E.OC1" is always lit at starting, disconnect the motor once and start the inverter.
If "E.OC1" is still lit, contact your sales representative.
 Check the wiring to make sure that output short circuit/ground fault does not occur.
Corrective action
 Set 50Hz in Pr. 3 Base frequency. (Refer to page 88.)
 Lower the setting of stall prevention operation level.
Activate the fast-response current limit operation. (Refer to page 82.)
 Set base voltage (rated voltage of the motor, etc.) in Pr. 19 Base frequency voltage. (Refer to page 88.)
Operation panel
E.OC2
indication
Name Overcurrent trip during constant speed
When the inverter output current reaches or exceeds approximately 200% of the rated current during constant speed
Description
operation, the protective circuit is activated and the inverter output is shut off.
 Check for sudden load change.
 Check for output short-circuit/ground fault.
Check point
 Check if the stall prevention operation level is set too high.
Check if the fast-response current limit operation is disabled.
 Keep load stable.
 Check the wiring to make sure that output short circuit/ground fault does not occur.
Corrective action
 Lower the setting of stall prevention operation level.
Activate the fast-response current limit operation. (Refer to page 82.)
FR-PU04
FR-PU07
" is indicated when across S1 and SC and across S2 and SC are both shorted while using the safety stop
FR-PU04
FR-PU07
FR-PU04
FR-PU07
FR-PU04
FR-PU07
Causes and corrective actions
——
FN
" appears on the operation panel when the cooling fan stops due to
OC During Acc
Stedy Spd OC
5
261