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List of fault or alarm indications
Fault
∗5
Overcurrent trip during
constant speed
Appears when an overcurrent occurred during
constant speed operation.
y Keep load stable.
y Check the wiring to make sure that output short circuit/
ground fault does not occur.
y Lower the setting of stall prevention operation level.
y Activate the fast-response current limit operation.
Overcurrent trip during
deceleration or stop
Appears when an overcurrent occurred during
deceleration and at a stop.
y Increase the deceleration time.
y Check the wiring to make sure that output short circuit/
ground fault does not occur.
y Check the mechanical brake operation.
y Lower the setting of stall prevention operation level.
y Activate the fast-response current limit operation.
Regenerative
overvoltage trip during
acceleration
Appears when an overvoltage occurred during
acceleration.
y Decrease the acceleration time.
y Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885,
Pr. 886).
y Set the Pr.22 Stall prevention operation level correctly.
Regenerative
overvoltage trip during
constant speed
Appears when an overvoltage occurred during
constant speed operation.
y Keep load stable.
y Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885,
Pr. 886).
y Use the brake resistor, brake unit or power regeneration
common converter (FR-CV) as required.
y Set the Pr.22 Stall prevention operation level correctly.
Regenerative
overvoltage trip during
deceleration or stop
Appears when an overvoltage occurred during
deceleration and at a stop.
y Increase the deceleration time. (Set the deceleration time
which matches the moment of inertia of the load)
y Make the brake cycle longer.
y Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885,
Pr. 886).
y Use the brake resistor, brake unit or power regeneration
common converter (FR-CV) as required.
Inverter overload trip
(electronic thermal relay
function)
Appears when the electronic thermal relay
function for inverter element protection was
activated.
y Increase acceleration/deceleration time.
y Adjust the torque boost setting.
y Set the load pattern selection setting according to the load
pattern of the using machine.
y Reduce the load weight.
y Set the surrounding air temperature to within the
specifications.
Motor overload trip
(electronic thermal relay
function)
∗1
Appears when the electronic thermal relay
function for motor protection was activated.
y Reduce the load weight.
y For a constant-torque motor, set the constant-torque motor in
Pr. 71 Applied motor.
y Check that stall prevention operation setting is correct.
Heatsink overheat Appears when the heatsink was overheated.
y Set the surrounding air temperature to within the
specifications.
y Clean the heatsink.
y Replace the cooling fan.
Input phase loss ∗6 ∗7 ∗8
Appears if one of the three phases on the
inverter input side is lost. It may also appear if
phase-to-phase voltage of the three-phase
power input becomes largely unbalanced.
y Wire the cables properly.
y Repair a break portion in the cable.
y Check the Pr. 872 Input phase loss protection selection setting.
y Set Pr. 872 = "0" (without input phase loss protection) when
three-phase input voltage is largely unbalanced.
Stall prevention stop
Appears when the output frequency drops to 1Hz
as a result of deceleration due to the excess
motor load.
Reduce the load weight. (Check the Pr. 22 Stall prevention
operation level setting.)
Brake transistor alarm
detection
This function stops the inverter output if an alarm
occurs in the brake circuit, e.g. damaged brake
transistors. In this case, the inverter must be
powered off immediately.
Replace the inverter.
Output side earth
(ground) fault
overcurrent at start ∗6
Appears when an earth (ground) fault occurred
on the inverter's output side. (detects only at a
start)
Remedy the ground fault portion.
Output phase loss
If one of the three phases (U, V, W) on the
inverter's output side (load side) is lost during
inverter operation (except during DC injection
brake operation and when output frequency is
under 1Hz), inverter stops the output.
y Wire the cables properly.
y Check the Pr. 251 Output phase loss protection selection setting.
Function Name Description Corrective action Display