Fuji Electric FRENIC-HVAC User Manual page 393

• If an excessive load is applied when the current limiter operation level is set
extremely low, the inverter will rapidly lower its output frequency. This may
cause an overvoltage trip or dangerous turnover of the motor rotation due to
undershooting. Depending on the load, extremely short acceleration time may
activate the current limiting to suppress the increase of the inverter output
frequency, causing hunting (undesirable oscillation of the system) or activating
the inverter overvoltage trip (alarm OU). When specifying the acceleration time,
therefore, you need to take into account machinery characteristics and moment of
inertia of the load.
• The torque limiter and current limiter are very similar in function. If both are
activated concurrently, they may conflict with each other and cause hunting.
Avoid concurrent activation of these limiters.
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6.3 Details of Function Codes