Hitachi L100 Overload Restriction

3–25

L100 Inverter

Overload Restriction

If the inverter’s output current exceeds a preset current level you specify during acceleration or constant speed, the overload restriction feature automatically reduces the output frequency to restrict the overload. This feature does not generate an alarm or trip event. You can instruct the inverter to apply overload restriction only during constant speed, thus allowing higher currents for acceleration. Or, you may use the same threshold for both acceleration and constant speed. In the case of controlled deceleration, the inverter monitors both output current and DC bus voltage. The inverter will increase output frequency to try to avoid a trip due to over-current or over-voltage (due to regeneration).

Motor

Current

Restriction area

B 22

0

t

Output

frequency

0
		t
	B 23

When the inverter detects an overload, it must decelerate the motor to reduce the current until it is less than the threshold. You can choose the rate of deceleration that the inverter uses to lower the output current.

	“B” Function			Run		Defaults
Func.	Name /		Description	Mode	–FE	–FU	–FR	Units
				Edit
Code	SRW Display				(CE)	(UL)	(Jpn)
B_21	Overload restriction		Select the operating mode	✘	01	01	01	—
	operation mode		during overload conditions,
			three options, option codes:
	OLOAD MODE	ON
			00 ...Disabled
			01 ...Enabled for acceleration
			and constant speed
			02 ...Enabled for constant
			speed only
B_22	Overload restriction		Sets the level for overload	✘	Rated current x 1.25			A
	setting		restriction, between 50% and
			150% of the rated current of
	OLOAD LVL 03.75A
			the inverter, setting resolution
			is 1% of rated current
B_23	Deceleration rate at		Sets the deceleration rate when	✘	1.0	1.0	1.0	—
	overload restriction		inverter detects overload, range
			is 0.1 to 30.0, resolution is 0.1.
	OLOAD CONST 01.0

Parameters Drive Configuring