5-19
When the variable torque V/f pattern is selected (F37 = 0 or 3), the output voltage
ay be low and insufficient voltage output may result in less output torque of the
otor at a low frequency zone, depending on some characteristics of the motor itsel
m
m
f
an
mmended to increase the output voltage at the lo
d load. In such a case, it is reco
w
frequency zone using the non-linear V/f pattern.
R
cy
ecommended value: H50 =
H51 =
1/10 of the base frequency
1/10 of the voltage at base frequen
Torque boo
• Manual tor
st (F09
In tor
boost u
, co
t voltage is
the
f the
load, to give
olt
re a sufficient st
lly adjust the
outpu
oltage
m
nd its load by
te
level that guarantees smooth
p and yet does not c
no or light
load.
Torque boost
sure
stability since t
rega
ss of the load fluctua
Specify
e F0
rc
rated voltage at
shipment, F09
a
ides approx. 1
st
que boo
)
nstan
que
sing F09
the output v
to optimally
added to
basic V/f pattern, regardless o
age. To secu
atch the motor a
start-u
arting torque, manua
using F09. Specify an appropria
ause over-excitation with
t v
per F09 en
s high driving
tion.
he output voltage remains constant
rdle
th
9 data in pe
is preset to
entage to the
level that prov
base frequency 1 (F05). At factory
00% of starting torque.
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
t. To avoid such a situation, adjust torque boost to an appropriate level.
n-linear V/f pattern and the torque boost are used together, the torque
may overhea
When the no
boost takes effect below the frequency on the non-linear V/f pattern’s point.
Summary of Contents for FRENIC-Multi series
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