Fuji Electric frenic mini series, User Manual

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F43 Current Limiter (Operation condition)
F44 Current Limiter (Limiting level)
F43 enables or disables the current limiter. If it is enabled, the inverter controls the output
frequency while keeping the current set to F44 in order to prevent the motor from stalling.
With F43, you may select whether the current limiter works during constant speed operation
only (F43 = 1) or during both acceleration and constant speed operation (F43 = 2). Set F43
to 1, for example, to drive the motor at maximum performance in the acceleration zone and
to limit the drive current in the constant speed zone.
Operation condition (F43)
Select the motor running state in which the current limiter will work.
Set F43 to: The current limiter will work:
0 Disabled
1 During constant speed operation
2
During acceleration and constant
speed operation
Limiting level (F44)
Select the level at which the current limiter will be activated.
- Data setting range: 20 to 200% (Percentage ratio of rated current of the inverter)
• The current limiting feature selected by F43 and F44 are implemented by
software, so an operational delay may occur. To avoid the delay, use the current
limiter (hardware) simultaneously (H12 = 1).
• If an overload is applied when the limiting level is set extremely low, the
inverter will immediately lower its output frequency. This may cause an
overvoltage trip or dangerous turnover of the motor rotation due to
undershooting.
F50 Electronic Thermal Overload Relay (Discharging capability)
F51 Electronic Thermal (Allowable loss)
These function codes configure the electronic thermal overload relay to protect the braking
resistor from overheating.
To F50, enter the discharging capability described in the braking resistor specifications or
calculated by equation (1) or (2) on the next page. To F51, enter the allowable loss
calculated by equation (3) or (4).
For built-in braking resistors, set function codes F50 and F51 to 0 and 0.00, respectively.
Refer to Chapter 7, Section 7.2 "Selecting a Braking Resistor" for details.
Depending on the discharging capability margin of a braking resistor, the
electronic thermal facility may operate and issue the overheat alarm "
dbH ," even
if the actual temperature of the resistor is lower than that specified. Check braking
resistor performance again and review the data setting of function codes F50 and
F51.