Mitsubishi Electronics FR-S500 instruction manual Stall prevention Pr. 22 , Pr. 23 , Pr, Setting

Explanation of functions (parameters)

2.3.13 Stall prevention (Pr. 22 , Pr. 23 , Pr. 28 )

Set the output current level (% value to the inverter rated current) at which the output frequency will be adjusted to prevent the inverter from stopping due to overcurrent etc.

During high-speed operation above the rated motor frequency, acceleration may not be made because the motor current does not increase. 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 range on a centrifugal separator etc. Normally, set 60Hz in Pr. 28 "stall prevention operation reduction starting frequency" and 100% in Pr. 23.

Parameter	Name	Factory	Setting	Remarks
		Setting	Range
22	Stall prevention operation	150%	0 to 200%	
	level				Setting is
	Stall prevention operation
			0 to 200%,	- - -: Pr. 22	enabled
23	level compensation factor at	- - -
			- - -	equally	when
	double speed
					Pr. 30 = "1".
28	Stall prevention operation	60Hz	0 to 120Hz	
	reduction starting frequency

						(%)
						compensation factor		Setting example
		Pr.22	When Pr.23 ="- - -"						(Pr.22= 150%,
								150	Pr.23=100%, Pr.28=60Hz)
								112.5
								90
				Pr.23				75
preventionStall	operationlevel(%)				Reductionratio		preventionStall	operationlevel(%)
			Pr.28	120Hz Output				0	6080100120 Output
				frequency (Hz)					frequency (Hz)
<Setting>

•Generally, set 150% (factory setting) in Pr. 22 "stall prevention operation level". Setting "0" in Pr. 22 disables stall prevention operation.

•To reduce the stall prevention operation level in the high frequency range, set the reduction starting frequency in Pr. 28 "stall prevention operation reduction starting frequency" and the reduction ratio compensation factor in Pr. 23.

Formula for stall prevention operation level

Stall prevention operation level (%) = A + B ×[				Pr. 22-A	]×[	Pr. 23-100	]
				Pr. 22-B		100
where, A =	Pr. 28 (Hz) × Pr. 22 (%)	, B =	Pr. 28 (Hz) × Pr. 22 (%)
	output frequency (Hz)			120Hz

•By setting "- - -" (factory setting) in Pr. 23, the stall prevention operation level is constant at the Pr. 22 setting up to 120Hz.

2

FUNCTIONS

77