Altivar® 58 TRX AC Drives
Drive and Motor Configuration Parameters
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09/2003 © 2000–2003 Schneider Electric All Rights Reserved
A higher switching frequency will produce a wa veform with l ess harmonic distortion and al low the current
regulator in the drive controller to perform better. Cable lengths greater than 330 feet (100 m) may
require adjusting the switching frequency to lower settings to redu ce the tr ansmission line phenomena
that tends to develop in long conductors.
Motor Noise Reduction
When this parameter is enabled, the switching frequency is randomly modulated to avoid audible
resonance from the motor. This parameter is useful in applications where audible motor noise is
undesirable.
Energy Economizer
This function is enabled when the Variable T orque macro-configurat ion is selected. W hen this para meter
is enabled, the drive controller optimizes the motor efficiency b y au tom ati cal ly adj us tin g the volts/hertz
ratio. The drive controller accelerates the load with a constant volts/hertz ratio. When the reference
speed is attained, the drive controller begins lowering the voltage app lied until the curren t begins to rise.
It operates at this point until the speed reference is cha nged. This param eter is usefu l f or sa ving ene rgy
in all variable torque applications.
Volts/Hertz Adjustment
This function is available in variable torque mode and if the Energ y Economize r function is disable d. This
parameter is useful in applications where the user wishes to define the volts/hertz profile manually
instead of having the drive controller perform this function with the Energy Economizer function.
The factory default is set to 20%, with an adjustment range of 0 to 100%.
Current Limit Adaptation
This function is available in variable torque mode, and provides for the automatic adaptation of the
current limit according to the speed to avoid a motor overload fault. It is used in applications involving
fans where the load curve of the fan changes with the air density, as shown in the graph to the left.
Special Motor Adaptation
This parameter should be enabled when using special mo tors such as s ynchronous permanent magnet
motors, synchronous wound field motors, or synchronous reluctance motors. This parameter should
also be enabled when one drive is used to control multip le motors in para llel. See the Thermal Prot ection
of Motor below for more information. Enabling t his parameter incr eases the IR c ompensation adju stment
range from 0 to 800%. This parameter can also be used in test ing when a ve ry small motor is used o nly
to verify proper operation of a drive system wiring and control.
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Current Limit
Adaptation Curves