Mitsubishi Electric FR-A700 Series, Technical Manual

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337
PARAMETER
2
P
ARAM
ETE
R
*1 The smaller setting of the stall prevention operation
levels set in [
Pr. 22 ] and [ Pr. 48 ] has a higher priority.
When [ Pr. 48 = 0], stall prevention level operates as 0%.
*2 Even when stall prevention operation level is variable by
analog input, turning the RT signal ON also switches
from analog input level to the stall prevention operation
level using [
Pr. 48 ]. (The second stall prevention
operation level cannot be input by analog.)
*3 When [ Pr. 48 = 0], stall prevention operation is not
performed.
*4 When X9 signal is turned ON, the third stall prevention
function has precedence.
*1 As set in Second stall prevention operation.
*2 Stall operation level is as set in [ Pr. 48 ] when the RT
signal is ON with [ Pr. 49 = 9999]. When [ Pr. 48 = 0], stall
prevention operation is not performed.
*3 The smaller setting of the stall prevention operation
levels set in [
Pr. 22 ] and [ Pr. 114 ] has a higher priority.
When [ Pr. 114 = 0], stall prevention level operates as 0%.
(3) Stall prevention at double speed [Pr. 23,
Pr. 66]
During high-speed operation above the rated motor
frequency, acceleration may not be made because
the motor current does not increase. If operation is
performed in a high frequency range, the current at
motor lockup becomes smaller than the rated output
current of the inverter, and the protective function
(OL) is not executed even if the motor is at a stop.
To improve the operating characteristics of the motor
in this case, the stall prevention level can be reduced
in the high frequency range. This function is effective
for performing operation up to the high-speed range
on a centrifugal separator etc. Normally, set [
Pr. 66 =
60Hz] and [
Pr. 23
= 100%].
Setting [ Pr. 23 Stall prevention operation level
compensation factor at double speed = 9999] (initial
value) will make the stall prevention operation level
constant up to 400Hz with [
Pr. 22
] setting.
[Setting example] [ Pr. 22 = 120%], [ Pr. 23 = 100%], [ Pr. 66 =
60Hz]
[Pr. 49]
Setting
Stall Prevention Operation Level
RT signal-OFF RT signal-ON
0(initial
value)
[ Pr. 22 ] (Second stall prevention function is not
activated)
0.01 to
400Hz
9999
*2
[ Pr. 22 ] [ Pr. 48 ]
*3
[Pr. 115]
Setting
Stall Prevention Operation Level
X9
Signal-
OFF:
X9 Signal-ON:
0(initial
value)
[ Pr. 22 ] *1 (Third stall prevention function is not
activated)
0.01 to
400Hz
[ Pr. 22 ] *1
A700 F700
Output
frequency
≤
[Pr. 49]
[Pr. 49]
< Output
frequency
Acceleration [
Pr. 22
]
Constant
speed
Deceleration
[ Pr. 48 ] *1 [ Pr. 22 ]
A700
Output
frequency
≤
[Pr. 115]
[Pr. 115] <
Output
frequency
Accelera
tion
[ Pr. 22 ]
*2
Constant
speed
Decelera
tion
[ Pr. 114 ]
*3
[ Pr. 22 ]
*3
Stall prevention
operation level at = A+B
[ Pr. 22 ]-A [ Pr. 23 ] -100
[ Pr. 22 ]-B 100
Note that A =
[ Pr. 66 ](Hz) [ Pr. 22 ](%)
Output frequency (Hz)
B =
[ Pr. 66 ](Hz) [ Pr. 22 ](%)
400 (Hz)
common
(
(
(
(
Output frequency (Hz)
= Pr.22 ]
When [ Pr.23 = 9999]
=
Pr.66 ]
400Hz
Stall prevention operation level (%)
18
0 100 60 200 300 400
24
36
72
120
Output frequency (Hz)
Stall prevention operation level (%)