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