Brake Opening Request (Bof) Signal (Pr. 281, Pr. 283) - Mitsubishi Electric FR-D720-0.2K-G Instruction Manual

Motor brake and stop operation

4.10.2 Brake opening request (BOF) signal (Pr. 281, Pr. 283)

Use the Brake opening request (BOF) signal to activate the electromagnetic brake.
The electromagnetic brake can be opened while voltage is output so that no drop may occur in a lift application.
Parameter
Name
Number
Brake operation time at
281
start
Brake operation time at
283
stop
.......Specifications differ according to the date assembled. Refer to page 294 to check the SERIAL number.
Interlock can be provided for the electromagnetic brake operation by setting a delay time from output of the Brake opening

request (BOF) signal to start of the actual operation in Pr. 281 Brake operation time at start.
Interlock can be provided for the electromagnetic brake operation or the output is shut off after electromagnetic brake

operation completes by setting a delay time from shutoff of the BOF signal to shutoff of the base circuit in Pr. 283 Brake
operation time at stop.
The delay time set in Pr. 281 and Pr. 283 are enabled even if the BOF signal is not assigned. Set "0" in both Pr. 281 and Pr.

283 if the delay time setting is not required.
To use the BOF signal, set "20 (positive logic) or 120 (negative logic)" in Pr. 190 or Pr. 192 (output terminal function selection)

to assign the function to an output terminal.
Additionally configure an external circuit, which can also command an emergency stop to the electromagnetic brake.

Power supply for
electromagnetic brake
STF
Base circuit
RY2
RY3
BOF
Electromagnetic
brake operation
 The release of the electromagnetic brake is delayed for the electromagnetic brake release/operation time and the operation time of the relays,
etc. in external circuits.
Start Signal
OFF (during a
stop)
RY
ON
RY2
OFF
RY3
OFF
RUN
OFF
BOF
OFF
 During a fault occurrence, or while the MRS signal is ON
NOTE
 Changing the terminal assignment using Pr. 190 or Pr. 192 (output terminal function selection) may affect the other functions. Set
parameters after confirming the function of each terminal. (Refer to page 123.)
 The BOF signal is not activated while the main circuit capacitor life is being measured. (Refer to page 231.)
112
Initial Value
0s
0s
Brake opening
request (BOF)
ON
Magnetic pole
detection
Pr. 281
100ms
Magnetic pole
detection
Open delay time +
external relay, etc.∗
Operation
Initial
Magnetic Pole Pr. 281
Detection
ON ON
OFF ON
OFF OFF
OFF OFF
OFF ON
Setting
Range
Set a time from output of the BOF signal to start of the actual
0 to 1s
operation (the electromagnetic brake open delay time)
Set a time from shutoff of the BOF signal to shutoff of the
0 to 1s
base circuit (the electromagnetic brake operation delay time)
Fault output Emergency stop
(ALM)
Pr. 11 Pr. 283
Voltage output
ON
ON
ON
Open
During DC
During
Injection Brake
Running
Operation
ON ON
ON ON
ON ON
ON OFF
ON ON
Description
B Electromagnetic brake
During DC injection
brake operation
Brake delay time +
external relay, etc.∗
Operation
Pr. 283
ON
ON
OFF
OFF
OFF
Output
Shutoff *
OFF
OFF
OFF
OFF
OFF