Brake Sequence Function (Pr. 278 To - Mitsubishi Electric FR-A700 Instruction Manual

Parameter
6.13.5 Brake sequence function
(Pr. 278 to Pr. 285, Pr. 292)
This function is used to output from the inverter the mechanical brake operation 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.
Pr.
Name
No.
278
Brake opening frequency
279
Brake opening current
Brake opening current
280
detection time
Brake operation time at
281
start
282
Brake operation frequency
Brake operation time at
283
stop
Deceleration detection
284
function selection
Overspeed detection fre-
285
quency
Automatic acceleration/
292
deceleration
When exercising vector control with the FR-A7AP, this parameter changes to excessive
speed deviation detection frequency (For details, refer to section 6.3.6)
When Pr. 570 Multiple rating setting ≠ "2", performing all parameter clear and inverter reset
changes the setting range. (Refer to section 6.7.5)
FR-A700 EC
Magnetic flux Magnetic flux Magnetic flux
Initial Setting
Description
Value Range
Set to the rated slip frequency of the
motor + about 1.0Hz.
3Hz 0–30Hz
This parameter may be set only 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 gravity at
130%
0–220%
start.
Suppose that the rated inverter current
is 100%.
Generally, set this parameter to about
0.3s 0–2s
0.1 to 0.3s.
When Pr. 292 = 7, set the mechanical
delay time until the brake is loosened.
0.3s 0–5s Set the mechanical delay time until the
brake is loosened + about 0.1 to 0.2s
when Pr. 292 = 8.
Set the frequency to activate the
mechanical brake by turning off the
brake opening request signal (BOF).
6Hz 0–30Hz Generally, set this parameter to the
Pr. 278 setting + 3 to 4Hz.
This parameter may be set only if Pr.
278 ≤ Pr. 282.
Set the mechanical delay time until the
brake is closed + 0.1s when Pr. 292 = 7.
0.3s 0–5s Sets the mechanical delay time until the
brake is closed + 0.2 to 0.3s when
Pr. 292 = 8.
0 Deceleration is not detected.
If deceleration is not normal during
0
1 deceleration operation,the inverter
alarm is provided.
If (detected frequency) - (output fre-
quency) If (detected frequency) - (out-
put frequency) >= Pr. 285 during
0–30Hz
9999
encoder feedback control, the inverter
alarm (E.MB1) is provided.
9999 Overspeed is not detected
0 Normal operation mode
Shortest acceleration/deceleration mode
1/11
(Refer to page 6-209)
Optimum acceleration/deceleration
3
9999 mode (Refer to page 6-210)
5/6 Elevator mode (Refer to section 6.9.3)
7 Brake sequence mode 1
8 Brake sequence mode 2
Motor brake and stop operation
Sensorless Sensorless Sensorless Vector Vector Vector
Parameters referred to
80
81
178–186
190–196
Refer to
Section
Motor capacity 6.2.2
Number of motor 6.2.2
poles
Input terminal 6.14.1
function selection
Output terminal 6.14.5
function selection
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