Fuji Electric FRENIC-Ace series - Torque Boost

5.3 Description of Function Codes
5-85
FUNCTION CODES
Chap 5
When the variable torque V/f pattern is selected (F37 = 0 or 3), the output voltage may be low at a low
frequency zone, resulting in insufficient output torque, depending on the characteristics of the motor and
load. In such a case, i
t is recommended to increase the output voltage at the low frequency zone using
the non
-linear V/f pattern.
Recommended value:
H50 = 1/10 of the base frequency
H51 = 1/10 of the voltage at base frequency
■ Torque boost
• Manual torque boost by F09 (Manual adjustment)
• Data setting range: 0.0 to 20.0 (%), (100%/base frequency voltage)
In torque boost using F09, constant voltage is added to the basic V/f pattern, regardless of the load. To secure a
sufficient starting torque, manually adjust the output voltage to optimally match the motor and its load by using F09.
Specify an appropriate level that guarantees smooth Startup and yet does not cause over-excitation at no or light
load.
Torque boost using F09 ensures high driving stability since the output voltage remains constant regardless of the
load fluctuation.
Specify the function code F09 data in percentage to the base frequency voltage. At factory shipment, boost amount
with which approx. 100% of starting torque can be assured, is specified.
• Specifying a high torque boost level will generate a high torque, but may cause overcurrent due to
over-excitation at no load. If you continue to drive the motor, it may overheat.
To avoid such a
situation, adjust torque boost to an appropriate level.
•
When the non-
linear V/f pattern and the torque boost are used together, the torque boost takes effect
below the frequency on the non-linear V/f pattern’s point.
Output voltage (V)
Rated voltage at
base frequency 1
Non-linear V/f
pattern 1 (voltage)
Non-linear V/f
pattern 1
(frequency)
V/f pattern of variable
torque V/f pattern
without non-linear V/f
V/f pattern of variable
torque V/f pattern with
non-linear V/f
Base
frequency 1
Output frequency
Rated voltage at
base frequency 1
Non-linear V/f
pattern 1 (voltage)
Increase output
voltage with Torque
boost 1 (F09)
Non-linear V/f
pattern 1
(frequency)
Base
frequency 1
Output frequency
Output voltage (V)
Torque boost 1