Hitachi SJ300 Series Engineering Note

Brand: Hitachi

Model: SJ300 Series

Type: Engineering Note

This manual is also suitable for

L300P Series

Hitachi SJ300 Series is a versatile frequency inverter that provides precise control of AC induction motors in various industrial applications. With its advanced features like Optimal Accel/Decel Operation, Energy-Saving Operation, and support for V/F Control modes, the SJ300 Series optimizes motor performance and efficiency. It enables dynamic adjustment of acceleration and deceleration times based on load conditions, resulting in shorter cycle times and improved productivity.

Hitachi America, Ltd.

EN-021302-1

ENGINEERING NOTE

SUBJECT: Parameter A85, Operation Mode Selection

AFFECTED MODELS: L300P and SJ300

The manuals for the SJ300 and L300P show three settings for Parameter A85.

This is ONLY correct for the SJ300.

There are only TWO settings for the L300P: “00” for Normal Operation, and “01”

for Energy-Saving Operation. The latter setting seeks to adjust the output voltage

at any given output frequency to minimize the motor current, and hence power

consumption at that speed. This function only acts at constant speed – not during

acceleration or deceleration.

Optimal Accel/Decel Operation (SJ300 ONLY)

In addition to “Normal” and “Energy Saving” modes, the SJ300 offers a third

setting option, “02” for Optimal Accel/Decel Operation. This function is an

implementation of a “fuzzy logic” algorithm. In real time, the function

automatically adjusts the acceleration and deceleration times in response to

changes in load or inertia, to take advantage of the maximum output current

capability of the inverter. In general, this mode will allow for the shortest accel

and decel times based on the actual load conditions. The function continuously

monitors output current and DC bus voltage to ensure that their respective trip

levels are not reached. In this mode, the settings of acceleration and deceleration

times (F002 and F003) are disregarded.

The acceleration time is controlled to maintain output current below the level set

by the Overload Restriction Function if enabled (Parameters B21/B24, B22/B25,

and B23/B26). If Overload Restriction is not enabled, then the current limit used

is 150% of the inverter’s rated output current.

The deceleration time is controlled so that the output current is maintained below

150% of the inverters rated current, AND the DC bus voltage is maintained below

the OV Trip level (358V or 770V).

PGC - 2/13/02 Page 1 of 2

EN-021302-1

Notes and Precautions

1. Do not use this setting (A85 = 02) on a machine where a constant

acceleration and/or deceleration time is desired.

2. Do not use this setting (A85 = 02) if the load inertia exceeds about 20 times

the motor shaft inertia.

3. Do not use this setting (A85 = 02) if the inverter will increase and decrease

speed frequently, as nuisance trips may occur.

4. Do not use this setting (A85 = 02) if internal or external regenerative braking

is being used.

5. Do not use this setting (A85 = 02) with any of the Vector Control modes

(A44 = 03, 04, or 05). This function is ONLY compatible with V/F Control

modes (A44 = 00, 01, or 02).

6. If the load exceeds the rating of the inverter, the acceleration time may be

increased.

7. If using a motor the capacity of which is one size smaller than the inverter

rating, enable the Overload Restriction function (B21/B24) and set the

Overload Restriction Level (B22/B25) to 1.5 times the motor nameplate

current.

8. Be aware that the acceleration and deceleration times will vary depending on

the actual load conditions that exist during each individual operation of the

inverter.

PGC - 2/13/02 Page 2 of 2

Hitachi SJ300 Series Engineering Note

Brand: Hitachi

Model: SJ300 Series

Type: Engineering Note

This manual is also suitable for

L300P Series

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Hitachi SJ300 Series Engineering Note

This manual is also suitable for

Hitachi SJ300 Series Engineering Note

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