Mitsubishi Electric FR-A700 Technical Manual page 367

(3) Without brake opening completion signal
input [Pr. 278 to 283, Pr. 292 = 8]
When the start signal is input to the inverter, the
inverter starts running. When the output frequency
reaches the value set in [Pr. 278] and the output
current is more than the value set in [Pr. 279] , the
inverter outputs the brake opening request signal
(BOF) after the time set in [Pr. 280] has elapsed.
When the time set in [Pr. 281] elapses after the BOF
signal is output, the inverter increases the output
frequency to the set speed.
When the speed has decreased to the frequency set
in [Pr. 282] during deceleration, the brake opening
request signal (BOF) is turned OFF. When the time
set in [Pr. 283] has elapsed after the BOF signal is
turned OFF, the inverter output is switched OFF.
Output frequency (Hz)
Target frequency
[Pr.280]
[Pr.282]
[Pr.278]
[Pr.13]
STF
Output
I [Pr.279]
Brake opening request
(BOF signal)
Closed
Electromagnetic brake
operation
(4) Protective function [Pr. 284, Pr. 285]
If any of the following errors occurs in the brake
sequence mode, the inverter results in an alarm,
shuts off the output, and turns OFF the brake
opening request signal (BOF).
Error
Display
During encoder feedback control
When (detected frequency) - (output
E.MB1
*1 frequency)
When [Pr. 285 = 9999] (overspeed detection
function), overspeed is not detected.
When deceleration is not normal during
deceleration operation from the set frequency
E.MB2
*1
to the frequency set in [Pr. 282]. (When [Pr. 284
= 1]) (except stall prevention operation)
Brake opening request signal (BOF) turned
E.MB3 ON though the motor is at a stop. (gravity drop
*1
prevention function)
Although more than 2s have elapsed after the
start command (forward or reverse rotation) is
E.MB4
input, the brake opening request signal (BOF)
does not turn ON.
Although more than 2s have elapsed after the
brake opening request signal (BOF) turned
E.MB5
ON, the brake opening completion signal (BRI)
does not turn ON.
[Pr.281]
Time
[Pr.283]
ON
ON
Opened Closed
Description
[Pr. 285]
Error
Display
Though the inverter had turned ON the brake
opening request signal (BOF), the brake
E.MB6
opening completion signal (BRI) turned OFF
midway.
Although more than 2s have elapsed after the
brake opening request signal (BOF) turned
E.MB7
OFF at a stop, the brake opening completion
signal (BRI) does not turn OFF.
*1 Not available for
*2 Overspeed detection ([
encoder feedback control (used with the FR-A7AP
or FR-A7AL option) even if a value other than 7 or
8 is set in [
Pr. 292
*3 A too large setting of [
activates stall prevention operation and may cause
E.MB4.
*4 When the acceleration time from [Pr.13 Starting
frequency] to [Pr.278 Brake opening frequency] plus
[Pr.280 Brake opening current detection time] exceeds
2s, E.MB4 occurs.
Output frequency
(Hz)
[Pr.278]
[Pr.13]
Brake opening request
(BOF)
401
PARAMETER
Description
E700
]) is valid under
Pr. 285
].
Pr. 278 Brake opening frequency
Less than 2s
Output
frequency(Hz)
[Pr.280]
Time
ON
]
2