Warning - Mitsubishi Electric FR-F800 Instruction Manual

Causes and corrective actions
Warning
Output is not shut off when a protective function activates.
Operation panel
indication
Name
Description
Check point
Corrective action
Operation panel
indication
Name
Description
Check point
Corrective action
538
PROTECTIVE FUNCTIONS
OL
Stall prevention (overcurrent)
• When the output current of the inverter increases, the stall prevention (overcurrent) function activates.
• The following section explains about the stall prevention (overcurrent) function.
When the output current of the inverter exceeds the stall prevention level (Pr.22 Stall
prevention operation level, etc.), this function stops the increase in frequency until the
During
overload current decreases to prevent the inverter from resulting in overcurrent trip.
acceleration
When the overload current has reduced below stall prevention operation level, this
function increases the frequency again.
When the output current of the inverter exceeds the stall prevention level (Pr.22 Stall
During prevention operation level, etc.), this function reduces frequency until the overload
constant-speed current decreases to prevent the inverter from resulting in overcurrent trip. When the
operation overload current has reduced below stall prevention operation level, this function
increases the frequency up to the set value.
When the output current of the inverter exceeds the stall prevention level (Pr.22 Stall
prevention operation level, etc.), this function stops the decrease in frequency until the
During
overload current decreases to prevent the inverter from resulting in overcurrent trip.
deceleration
When the overload current has decreased below stall prevention operation level, this
function decreases the frequency again.
• Check that the Pr.0 Torque boost setting is not too large.
• The Pr.7 Acceleration time and Pr.8 Deceleration time settings may be too short.
• Check that the load is not too heavy.
• Check for any failures in peripheral devices.
• Check that the Pr.13 Starting frequency is not too large.
• Check that Pr.22 Stall prevention operation level is appropriate.
• Gradually increase or decrease the Pr.0 setting by 1% at a time and check the motor status.(Refer to
page 496.)
• Set a larger value in Pr.7 Acceleration time and Pr.8 Deceleration time. (Refer to
• Reduce the load.
• Try Advanced magnetic flux vector control.
• Change the Pr.14 Load pattern selection setting.
• The stall prevention operation current can be set in Pr.22 Stall prevention operation level. The
acceleration/deceleration time may change. Increase the stall prevention operation level with Pr.22 Stall
prevention operation level, or disable stall prevention with Pr.156 Stall prevention operation selection.
(Use Pr.156 to set either operation continued or not at OL operation.)
oL
Stall prevention (overvoltage)
• When the output voltage of the inverter increases, the stall prevention (overvoltage) function activates.
• The regeneration avoidance function activates due to excessive regenerative power of the motor. (Refer to
page 514.)
• The following section explains the stall prevention (overvoltage) function.
If the regenerative power of the motor becomes excessive to exceed the regenerative
power consumption capability, this function stops decreasing the frequency to prevent
During deceleration
overvoltage trip. As soon as the regenerative power has reduced, deceleration
resumes.
• Check for sudden speed reduction.
• Check if the regeneration avoidance function (Pr.882 to Pr.886) is being used. (Refer to
The deceleration time may change. Increase the deceleration time using Pr.8 Deceleration time.
FR-PU07
FR-PU07
OL
page 187.)
oL
page 514.)