Mitsubishi Electronics FR-F700 Stall prevention operation, Input compensation of multi

Pr. 22, 23, 48, 49, 66, 148, 149, 154, 156, 157

Stall prevention operation

Pr.22 Stall prevention operation level

Pr.23 Stall prevention operation level compensation factor at double speed

Pr.48 Second stall prevention operation current	Pr.49 Second stall prevention operation frequency
Pr.66 Stall prevention operation reduction starting frequency
Pr.148 Stall prevention level at 0V input.	Pr.149 Stall prevention level at 10V input.
Pr.154 Voltage reduction selection during stall prevention operation
Pr.156 Stall prevention operation selection	Pr.157 OL signal output timer

This function monitors the output current and automatically changes the output frequency to prevent the inverter from coming to an alarm stop due to overcurrent, overvoltage, etc. It can also limit stall prevention and fast-response current limit operation during acceleration/deceleration, driving or regeneration.

￿ Stall prevention

If the output current exceeds the limit value, the output frequency

of the inverter is automatically varied to reduce the output current.

Also the second stall prevention function can restrict the output

frequency range in which the stall prevention function is valid.

(Pr.49)

￿ Fast-response current limit

If the current exceeds the limit value, the output of the inverter is

shut off to prevent an overcurrent.

￿ Set in Pr. 22 the ratio of the output current to the rated inverter

current at which stall prevention operation will be performed.

Normally set this parameter to120% (initial value).

￿ When “9999” is set in Pr. 22, stall prevention operation level can be

changed by the signal to the auxiliary input terminal (terminal 1). For

the adjustment of bias/gain of analog signal, use Pr. 148 and Pr. 149.

￿ 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

Pr. 49 Setting	Operation
0 (initial value)	Second stall prevention function is not activated
0.01Hz to 400Hz	If the output frequency is less than the frequency set in
	Pr. 49, the second stall prevention operation function is
	activated. (during constant speed or deceleration)
	The second stall prevention function is performed according to
9999	the RT signal.
	RT signal on ....... Stall level Pr. 48
	RT signal off ....... Stall level Pr. 22

￿Stall prevention operation and fast response current restriction function can be restricted according to the operation condition using Pr. 156.

Pr. 24 to 27			Refer to the section about Pr.4 to Pr.6
Pr.	28	Input compensation of multi-
		speed and remote setting

Pr.28 Multi-speed input compensation selection

By inputting the frequency setting compensation signal (terminal 1, 2), the speed (frequency) can be compensated for relative to the multi-speed setting or the speed setting by remote setting function.

Pr. 28 Setting	Definition
0 (initial value)	Without compensation
1	With compensation

Acceleration/ deceleration pattern
Pr. 29, 140 to 143 and back lash measures
Pr.29 Acceleration/deceleration pattern selection	Pr.140 Backlash acceleration stopping frequency
Pr.141 Backlash acceleration stopping time	Pr.142 Backlash deceleration stopping frequency
Pr.143 Backlash deceleration stopping time

You can set the acceleration/deceleration pattern suitable for application.

You can also set the backlash measures that stop acceleration/ deceleration once at the parameter-set frequency and time during acceleration/deceleration.

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executed 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

region. This function is effective for performing operation up to the

high speed region on a centrifugal separator etc. Normally, set

60Hz in Pr. 66 and 100% in Pr. 23.

￿ By setting "9999" (initial value) in Pr. 23 Stall prevention operation

level compensation factor at double speed, the stall prevention

operation level is constant at the Pr. 22 setting up to 400Hz.

Pr.22			Reduction ratio compensation
		When Pr.23=9999
Stall prevention operation level (%)		Pr.23		factor (%)
		400Hz
	Pr.66

Output frequency (Hz)

￿Setting "9999" in Pr. 49 Second stall prevention operation frequency and turning the RT signal on make Pr. 48 Second stall prevention operation current valid.

￿The stall prevention operation level from 0Hz to the output frequency set in Pr. 49 can be set in Pr. 48.

Set frequency exceeds Pr. 49 Set frequency is Pr. 49 or less

Output			Output
			frequency (Hz)
frequency (Hz)		Output
Set		frequency		Output
				frequency
frequency			Pr.49
Pr.49
			Set
			frequency
Stall		Time		Time
prevention
level	Pr. 22
	used	Pr. 48	Pr. 22	Pr. 48
			used	used
		used

Setting value "0"

Outputfrequency	[Linear acceleration
	/ deceleration]
	(Hz)
	Time

Setting value "1"

frequency	[S-pattern acceleration
	/deceleration A]
Output	fb
	(Hz)
	Time

Setting value "2"

		[S-pattern acceleration
		/deceleration B]
Set frequency	(Hz)
frequency	f1
Output	f2
	(Hz)	Time

(Hz)		Setting value "3"
	[Anti-backlash measure
frequency	function]
			f2
Output			Pr.142
		f1
		Pr.140
	t1	t2	Time
	Pr.141	Pr.143

￿Linear acceleration/deceleration (setting "0", initial value)

⋅When the frequency is changed for acceleration, deceleration, etc. in inverter operation, the output frequency is changed linearly (linear acceleration/deceleration) to reach the set frequency without straining the motor and inverter.

￿S-pattern acceleration/deceleration A (setting "1")

⋅For machine tool spindle applications, etc.

Use when acceleration/deceleration must be made in a short time to a high-speed region of not lower than base frequency.

￿S-pattern acceleration/deceleration B (setting "2")

⋅For prevention of load shifting in conveyor and other applications Since acceleration/deceleration is always made in an S shape from current frequency (f2) to target frequency (f1), this function eases shock produced at acceleration/ deceleration and is effective for load collapse prevention, etc.

￿Backlash measures (setting "3", Pr.140 to Pr.143 )

⋅To avoid backlash, acceleration/ deceleration is temporarily stopped. Set the acceleration/deceleration stopping frequency and time in Pr. 140 to Pr. 143.

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Pr. indicates simple mode parameters and Pr. indicates extended parameters. When setting parameters, refer to the instruction manual (applied) and understand instructions. 30