Mitsubishi Electric FR-A800, Instruction Manual

Page: 501 / 1042

Parameters (H) Protective function parameter
FR-A800 5 - 321
When Pr. 868 = "4" (analog stall prevention), the other functions for terminal 1 (auxiliary input,
override function, PID control) will be disabled.
When Pr. 858 = "4" (analog stall prevention), PID control and speed commands using terminal 4
will not operate, even if the AU signal turns ON.
When both of Pr. 858 and Pr. 868 are set to "4" (stall prevention), terminal 1 functions take priority
and terminal 4 has no function.
To further prevent a trip (Pr. 154)
●
When Pr. 154 "Voltage reduction selection during stall prevention operation" = "0, 10", the output
voltage is reduced. By making this setting, an overcurrent trip becomes less likely to occur. Use
this setting when torque reduction does not pose a problem. (Under V/F control, the output
voltage is reduced only during the stall prevention operation is activated.)
●
Set Pr. 154 = "10, 11" when the overvoltage protective function (E.OV
첸
) activates during stall
prevention operation in an application with large load inertia. Note that turning OFF the start
signal (STF/STR) or varying the frequency command during stall prevention operation may delay
the acceleration/deceleration start.
4
0
(initial value)
Stall prevention
Auxiliary frequency
1
⎯
2
⎯
3
⎯ ⎯
4
⎯
Stall prevention
5
Stall prevention
⎯
6
⎯
9999
⎯
9999
⎯ ⎯ ⎯
NOTE The fast-response current limit cannot be set.
Pr. 154 E.OC
첸
countermeasure E.OV
첸
countermeasure
0 Effective
⎯
1 (initial value)
⎯ ⎯
10 Effective Effective
11
⎯
Effective
Tab. 5-124: Settings of parameter 154
E
CAUTION:
●
Do not set the stall prevention operation current too low.
Doing so will reduce the generated torque.
●
Be sure to perform a test run.
Stall prevention operation during acceleration may extend the acceleration time.
Stall prevention operation during constant-speed operation may cause sudden speed
changes.
Stall prevention operation during deceleration may extend the deceleration time.
Pr. 858 setting Pr. 868 setting
V/F, Advanced magnetic flux vector control
Terminal 4 function Terminal 1 function
Tab. 5-123: Functions of terminal 1 and 4 in dependence of the control mode (2)