Hitachi SJ300 Series Basic Parameter Settings, SRW Display, “A” Function

3–9

SJ300 Inverter

“A” Group: Standard Functions

Basic Parameter Settings

These settings affect the most fundamental behavior of the inverter—the outputs to the motor. The frequency of the inverter’s AC output determines the motor speed. You may select from three different sources for the reference speed. During application development you may prefer using the potentiometer, but you may switch to an external source (control terminal setting) in the finished application, for example.

The base frequency and maximum frequency settings interact according to the graph below (left). The inverter output operation follows the constant V/f curve until it reaches the full-scale output voltage. This initial straight line is the constant-torque part of the operating characteris- tic. The horizontal line over to the maximum frequency serves to let the motor run faster, but at a reduced torque. This is the constant-horsepower part of the characteristic. If you want the motor to output constant torque over its entire operating range (limited to the motor nameplate voltage and frequency rating), then set the base frequency and maximum frequency equal as shown (below right).

V			V		A003
100%	A003	A004	100%		A004
				Constant torque

0			t	0		t
	Base	Maximum			Base frequency =
	Frequency	Frequency			maximum frequency

NOTE: The “2nd motor” and “3rd motor” settings in the tables in this chapter store an alternate set of parameters for additional motors. The inverter can use the 1st, 2nd, or 3rd set of parameters to generate the output frequency to the motor. See “Configuring the Inverter for Multiple Motors” on page 4–72.

Parameters Drive Configuring

		“A” Function			Run		Defaults
					Mode				Units	SRW Display
Func.					Edit	–FE	–FU	–FR
		Name		Description
	Code				Lo Hi	(EU)	(US)	(JP)
A001		Frequency source	Six options; select codes:		✘ ✘	01	01	02	—	>A001 F-SET
		setting	00 Keypad potentiometer							SELECT	TRM
			01	Control terminal
			02	Function F001 setting
			03	RS485 serial command
			04	Expansion board 1
			05	Expansion board 2
A002		Run command source	Five options; select codes:		✘ ✘	01	01	02	—	>A002 F/R
		setting	01 Input terminal [FW] or							SELECT	TRM
				[RV] (assignable)
			02	Run key on keypad, or
				digital operator
			03	RS485 serial command
			04	Start/Stop, expansion
				card #1
			05	Start/Stop, expansion
				card #2
A003		Base frequency setting	Settable from 30 Hz to the		✘ ✘	50.	60.	60.	Hz	>A003 F-BASE
			maximum frequency							F	0060Hz