Mitsubishi Electric FR-A700 Series, Technical Manual

Page: 367 / 550

401
PARAMETER
2
P
ARAM
ETE
R
(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.
(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
Description
E.MB1 *1
During encoder feedback control
When (detected frequency) - (output
frequency) [ Pr. 285 ]
When [ Pr. 285 = 9999 ] (overspeed detection
function), overspeed is not detected.
E.MB2
*1
When deceleration is not normal during
deceleration operation from the set frequency
to the frequency set in [
Pr. 282 ]. (When [ Pr. 284
= 1 ]) (except stall prevention operation)
E.MB3
*1
Brake opening request signal (BOF) turned
ON though the motor is at a stop. (gravity drop
prevention function)
E.MB4
Although more than 2s have elapsed after the
start command (forward or reverse rotation) is
input, the brake opening request signal (BOF)
does not turn ON.
E.MB5
Although more than 2s have elapsed after the
brake opening request signal (BOF) turned
ON, the brake opening completion signal (BRI)
does not turn ON.
STF
ON
I
ON
[ Pr.278 ]
[ Pr.282 ]
Target frequency
(Hz)
[ Pr.281 ]
[ Pr.283 ]
[ Pr.280 ]
[ Pr.279 ]
[ Pr.13 ]
Output frequency
Output
Brake opening request
(BOF signal)
Electromagnetic brake
operation
Closed Opened Closed
Time
E.MB6
Though the inverter had turned ON the brake
opening request signal (BOF), the brake
opening completion signal (BRI) turned OFF
midway.
E.MB7
Although more than 2s have elapsed after the
brake opening request signal (BOF) turned
OFF at a stop, the brake opening completion
signal (BRI) does not turn OFF.
*1 Not available for
*2 Overspeed detection ([
Pr. 285
]) is valid under
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 [
Pr. 278 Brake opening frequency
]
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.
Error
Display
Description
E700
Brake opening request
(BOF)
ON
Time
[ Pr.278 ]
[ Pr.280 ]
[ Pr.13 ]
Output frequency
(Hz)
Output
frequency(Hz)
Less than 2s