Brake Sequence Function; Speed Deviation Excess Detection - Mitsubishi Electric FR-A700 Manual

Pr.
Pr.
278 to 285, 292

Brake sequence function

Magnetic flux Magnetic flux Magnetic flux
Pr.278 Brake opening frequency
Pr.280 Brake opening current detection time
Pr.282 Brake operation frequency
Pr.284 Deceleration detection function selection
Pr.292 Automatic acceleration/deceleration
This function is used to output from the inverter the mechanical
brake opening completion signal timing signal in vertical lift and
other applications.
This function prevents the load from dropping with gravity at a start
due to the operation timing error of the mechanical brake or an
overcurrent alarm from occurring at a stop, ensuring secure
operation.
<Operation example>
At start: When the start signal is input to the inverter, the inverter
starts running. When the internal speed command reaches
the value set in Pr.278 and the output current is not less
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 brake opening
completion signal (BRI) was activated, the inverter
increases the output frequency to the set speed.
At stop: When the speed has decreased to the frequency set in
Pr.282 , the brake opening request signal (BOF) is turned
off. When the time set in Pr.283 elapses after the brake
operation confirmation signal (BRI) was activated, the
inverter output is switched off.
* If Pr.292 = "8" (mechanical brake opening completion signal
not input), this time is the time after the brake opening request
signal is output.
1)Pr.292 = "7" (brake opening completion signal input)
Output frequency(Hz)
Target frequency
Pr.280
Pr.282
Pr.278
Pr.13
STF
Pr.279
Output I
Brake opening request
(BOF signal)
Brake opening completion
(BRI signal)
Closed
Electromagnetic brake
operation
2)Pr.292 = "8" (brake opening completion signal not input)
Output frequency (Hz)
Target frequency
Pr.280
Pr.282
Pr.278
Pr.13
STF
Pr.279
Output I
Brake opening request
(BOF signal)
Closed
Electromagnetic brake
operation
When setting parameters, refer to the instruction manual (applied) and understand instructions.
Sensorless Sensorless Sensorless Vector Vector Vector
Pr.279 Brake opening current
Pr.281 Brake operation time at start
Pr.283 Brake operation time at stop
Pr.285 Overspeed detection frequency
Pr.281
Time
Pr.283
ON
ON
ON
Opened Closed
Pr.281
Time
Pr.283
ON
ON
Opened Closed
Setting
Pr.
Range
Number
Set to the rated slip frequency of the motor + about
278 0 to 30Hz
1.0Hz.
This parameter may be only set if Pr.278 ≤ Pr.282.
Generally, set this parameter to about 50 to 90%. If
the setting is too low, the load is liable to drop due to
279 0 to 220%
gravity at start.
Suppose that the rated inverter current is 100%.
280 0 to 2s
Generally, set this parameter to about 0.1 to 0.3s.
Pr.292 = 7: Set the mechanical delay time until the
brake is loosened.
281 0 to 5s
Pr.292 = 8: Set the mechanical delay time until the
brake is loosened+about 0.1 to 0.2s.
At this frequency, the brake opening request signal
(BOF) is switched off.Generally, set this parameter to
282 0 to 30Hz
the Pr.278 setting + 3 to 4Hz.
This parameter may only be set if Pr.282 ≥ Pr.278.
Pr.292 =7: Set the mechanical delay time until the
brake is closed + 0.1s.
283 0 to 5s
Pr.292 =8: Set the mechanical delay time until the
brake is closed + 0.2 to 0.3s.
0
Deceleration is not detected.
(initial value)
If deceleration is not normal during deceleration
284
operation, the inverter alarm (E.MB2) is provided to
1
shut off the output and turn off the brake opening
request signal (BOF).
When brake sequence function is made valid under
encoder feedback control
If (detected frequency) - (output frequency) > Pr.285
0 to 30Hz
the inverter alarm (E.MB1) is provided to shut off the
285
output and turn off the brake opening request signal
(BOF).
9999
Overspeed is not detected.
(initial value)
0, 1, 3,
Brake sequence function is made valid when a setting
292
5 to 8, 11
is "7 or 8".
Pr.
Pr.
285, 853

Speed deviation excess detection

Pr.285 Speed deviation excess detection frequency
If the difference (absolute value) between the speed command
value and actual speed exceeds the Pr. 285 Speed deviation excess
detection frequency setting for longer than the time set in Pr. 853 Speed
deviation time during speed control under vector control, speed
deviation excessive occurs and error "E. OSD" appears, resulting in
a stop.
(Hz)
Pr.853
Alarm output
OFF
(across A-C)
Speed deviation
excessive error activated
Description
Vector Vector Vector
Pr.853 Speed deviation time
Set frequency
Pr.285
Actual speed
Time
ON
(E. OSD)
64