High-Efficiency Operation Voltage Reduction Time [Sec]; High-Efficiency Operation Voltage Lower Limit Setting Value [%]; High-Efficiency Operation Principle; Dbr Option Selection - GE VAT2000 Instruction Manual

C25-0

High-efficiency operation Voltage reduction time [sec]

This setting value is the time to
reduce the output voltage from the
V/f setting value to 0V after the
output frequency reaches the set
frequency.
Normally, set the specified value
(1.0). When using for loads with
sudden torque fluctuations, and the
output frequency drops remarkably
with the overcurrent limit function,
set a lower value. If the rotation
becomes unstable during the voltage
reduction or recovery operations, even causing a trip, set an higher value.
C25-1

High-efficiency operation Voltage lower limit setting value [%]

Set a value between 10 and 99 while
the inverter is stopped to select the
high-efficiency operation function.
When not using the high-efficiency
operation function, set 100 while the
inverter is stopped.
This setting value is the lower limit of
the output voltage reduced when the
high-efficiency operation function is
selected, and uses the V/f setting
voltage (output voltage when not
using high-efficiency operation) as
the reference.
Normally, the minimum value (10) is set. When using for loads with sudden torque
fluctuations, and the output frequency drops remarkably with the overcurrent limit function,
set an appropriately high value.

high-efficiency operation principle

Normally for the V/f constant operation, the no-load loss is large with a light load, and the
motor efficiency drops remarkably. Thus, according to the load, the output voltage is reduced
using the C25-1 setting value as the lower limit in respect to the voltage set with V/f, and the
motor efficiency is improved.
(Note) Slipping will increase during high-efficiency operation, so it is recommended to
C31-0

DBR option selection

Select the usage of the motor loss braking and DBR resistor (built-in or external).
Refer to the explanation on the motor loss braking setting (C22-4) for details on the motor
loss braking function.
The motor loss braking function is valid only when the V/f control mode (C30-0 = 1, 2) is
selected.
6. Control Functions and Parameter Settings
execute automatic tuning before operation and set the automatic torque boost
selection to valid (A02-1 =2).
O u tp u t vo lta g e
V /f s ettin g v o lta g e
R e d u ce d vo lta g e
O utpu t vo lta ge
V /F settin g vo lta g e
6-69
C 2 5 -0
(0 .1 ~ 3 0 .0 )
1 00 %
O utpu t vo lta ge fluctu atio n
a t fre q ue ncy f
C 2 5-1 settin g (10 -10 0% )
L ow e r lim it of ou tp ut vo lta g e
to b e red uced
Fre q ue ncy
f
1 0 0 %
C 2 5 -1
(1 0 ~1 0 0 )
Tim e