Fuji Electric FRENIC-MEGA - Page 219

5-130
F codes
E codes
C codes
P codes
H codes
A codes
b codes
r codes
J codes
d codes
U codes
y codes
Chap. 5 FUNCTION CODES
 Brake signal -- BRKS (E20 to E24 and E27, data = 57)
This signal outputs a brake control command that releases or activates the brake.
Releasing the Brake
When any of the inverter output current, output frequency, or torque command value exceeds the specified level of the
brake signal (J68/J69/J95) for the period specified by J70 (Brake signal (Brake-OFF timer)), the inverter judges that
required motor torque is generated and turns the signal
BRKS ON for releasing the brake.
This prevents a hoisted load from falling down due to an insufficient torque when the brake is released.
Function code Name Data setting range Remarks
J68 Brake-OFF current
0% to 300%:
Set it putting the inverter rated current at
100%.
See Note below.
J69 Brake-OFF frequency/speed 0.0 to 25.0 Hz
Available only under
V/f control.
J70 Brake-OFF timer 0.0 to 5.0 s
J95 Brake-OFF torque 0% to 300%
Available only under
vector control.
The inverter rated current differs depending upon the drive mode selected (HD, MD or LD).
Turning the Brake ON
When the run command is OFF and the output frequency drops below the level specified by J71 (Brake signal
(Brake-ON frequency/speed)) and stays below the level for the period specified by J72 (Brake signal (Brake-ON timer)),
the inverter judges that the motor rotation is below a certain level and turns the signal
BRKS OFF for activating the
brake.
Under vector control, when the reference speed or the detected one drops below the level of the stop frequency
specified by F25 (Stop frequency) and stays below the level for the period specified by J72 (Brake signal (Brake-ON
timer)), the inverter judges that the motor rotation is below a certain level and turns the signal
BRKS OFF for activating
the brake.
This operation reduces the load applied to the brake, extending lifetime of the brake.
Function code Name Data setting range Remarks
J71 Brake-ON frequency/speed 0.0 to 25.0 Hz
Available only under V/f
control.
J72 Brake-ON timer 0.0 to 5.0 s
J96 Speed selection
0: Detected speed
1: Reference speed
Speed selection under vector control.
Available only under vector
control.
When vector control without
speed sensor is selected, set
to "1: Reference speed."
• The brake signal control is only applicable to the 1st motor. If the motor switching function selects any o
f
the 2nd to 4th motor, the brake signal remains ON.
• If the inverter is shut down due to an occurrence of alarm state or by the terminal command
BX ("Coast to a
stop"), the brake signal is turned ON immediately.
Operation time chart under V/f control
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