Mitsubishi Electric 800 Series Instruction Manual page 324

• When the inverter decelerates to the frequency set to Pr.282 Brake operation frequency during deceleration, the inverter
turns OFF the brake opening request signal (BOF) and decelerates further to the frequency set in Pr.278. And after the
time set in Pr.283 Brake operation time at stop passes, the inverter decelerates again. The inverter output is shut off
when the frequency reaches Pr.13 Starting frequency setting or 0.5 Hz, whichever is lower.
Output frequency(Hz)
Output current or motor torque
Brake opening request
Electromagnetic brake
NOTE
• Even if the brake sequence operation has been selected, inputting the JOG signal (JOG operation) during an inverter stop
changes the operation method to normal operation and give a priority to the JOG operation. Note that the JOG signal input by
the brake sequence function is invalid during operation.
 Protective function
• If one of the following faults occurs while the brake sequence function is enabled, the inverter enters a fault status, shuts
off output, and turns OFF the brake opening request signal (BOF).
Fault
indication
When 2 seconds or more have elapsed after the start command (forward or reverse rotation) is input, but the BOF signal
E.MB4
does not turn ON.
E.MB5 When 2 seconds or more have elapsed after the BOF signal turned ON, but the BRI signal does not turn ON.
E.MB6 When the inverter had turned ON the brake opening request signal (BOF), but the BRI signal turned OFF.
E.MB7 When 2 seconds or more have elapsed after the BOF signal turned OFF at a stop, but the BRI signal does not turn OFF.
NOTE
• During deceleration, inverter output is shut OFF when the frequency reaches Pr.13 Starting frequency or 0.5 Hz, whichever
is lower. For Pr.278 Brake opening frequency, set a frequency equal to or higher than the Pr.13 setting or 0.5 Hz.
• Setting Pr.278 too high activates the stall prevention and may cause E.MB4.
• E.MB4 occurs when the time period calculated by adding Pr.280 to the acceleration time from Pr.13 to Pr.278 reaches or
exceeds 2 seconds.
Parameters referred to
Pr.13 Starting frequencypage 169
Pr.178 to Pr.189 (Input terminal function
Pr.190 to Pr.196 (Output terminal function
Target frequency
Pr.280
Pr.282
Pr.278
Pr.13
STF
Pr.279
(select by Pr.639)
(BOF signal)
Closed
operation
Pr.278
Pr.13
Brake opening request
(BOF signal)
selection)page 283
selection)page 250
Pr.13 setting
or 0.5Hz,
Pr.281
whichever is lower
Pr.283
ON
ON
Opened Closed
Description
Less than 2s
Output
frequency
(Hz)
Pr.280
Time
ON
Time
14. (A) Application Parameters
14.1 Brake sequence function
11
12
13
14
15
16
17
18
19
20
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