Mitsubishi Electric FR-F800 Series Instruction Manual page 601

 Fault
When a protective function is activated, the inverter output is shut off and a Fault signal is output.
Operation panel
indication
Name
Description
Check point
Corrective action
Operation panel
indication
Name
Description
Check point
Corrective action
600
6. PROTECTIVE FUNCTIONS
6.5 Causes and corrective actions
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E.OC1
Overcurrent trip during acceleration
When the inverter output current reaches or exceeds approximately 170% (LD rating) / 148% (SLD rating) of the
rated current during acceleration, the protection circuit is activated and the inverter output is shut off.
• Check for sudden speed acceleration.
• Check if the downward acceleration time is too long in a lift application.
• Check for output short-circuit.
• Check that the Pr.3 Base frequency setting is not 60 Hz when the motor rated frequency is 50 Hz.
• Check if the stall prevention operation level is set too high. Check if the fast-response current limit operation is
disabled.
• Check that the regenerative driving is not performed frequently. (Check if the output voltage becomes larger
than the V/F reference voltage at regenerative driving and overcurrent occurs due to increase in the motor
current.)
• Check that the inverter capacity matches with the motor capacity. (PM motor control)
• Check if a start command is given to the inverter while the motor is coasting. (PM motor control)
• Set the acceleration time longer. (Shorten the downward acceleration time of the lift.)
• If "E.OC1" always appears at start, disconnect the motor once and restart the inverter.
If "E.OC1" still appears, contact your sales representative.
• Check the wiring to make sure that output short circuit does not occur.
• Set 50 Hz in Pr.3 Base frequency. (Refer to
• Lower the stall prevention operation level. Activate the fast-response current limit operation. (Refer to
290.)
• Set the base voltage (rated voltage of the motor, etc.) in Pr.19 Base frequency voltage. (Refer to
• Choose inverter and motor capacities that match. (PM motor control)
• Input a start command after the motor stops. Alternatively, use the automatic restart after instantaneous power
failure/flying start function. (Refer to
E.OC2
Overcurrent trip during constant speed
When the inverter output current reaches or exceeds approximately 170% (LD rating) / 148% (SLD rating) of the
rated current during constant-speed operation, the protection circuit is activated and the inverter output is shut
off.
• Check for sudden load change.
• Check for a short-circuit in the output circuit.
• Check if the stall prevention operation level is set too high. Check if the fast-response current limit operation is
disabled.
• Check that the inverter capacity matches with the motor capacity. (PM motor control)
• Check if a start command is given to the inverter while the motor is coasting. (PM motor control)
• Keep the load stable.
• Check the wiring to make sure that output short circuit does not occur.
• Lower the stall prevention operation level. Activate the fast-response current limit operation. (Refer to
290.)
• Choose inverter and motor capacities that match. (PM motor control)
• Input a start command after the motor stops. Alternatively, use the automatic restart after instantaneous power
failure/flying start function. (Refer to
search engine
FR-LU08 indication OC During Acc
page 552.)
page 472.) (PM motor control)
FR-LU08 indication OC During Cnst Spd
page 472.) (PM motor control)
page
page 552.)
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