Toshiba VF-SX - Manual (Page 130)

TOSHIBA
12-9
1. No-load Current Setting
The parameter [ CUrO] of the [Or.C C] group Is set by default to the
standard value, lOX. Additional adjustment is generally not required. However,
In the following cases adjustment of this parameter may be effective.
1. If an over-excited state occurs during low voltage output (when the output
frequency is low), slightly increase [
CUrO
]. If the torque is not
quite sufficient, lower this parameter slightly. The starting point of
the voltage can be adjusted with the torque boost setting value (parameter
[Ub ]
in family
[G f~. F ].)
This parameter regulates the lower limit
of the automatic torque boost function.
2. This parameter is also used as the setting data of the no-load current in
the slip frequency compensation function. When this parameter Is changed,
the setting data for the no-load current in slip frequency compensation
function will also be changed.
3. The value will not always be the same as the no-load current value noted
on the applicable motor data sheet or rating nameplate.
2. Torque Boost Maximum Value Setting
The maximum value of the automatic adjustment range is set by the parameter
[ U b H ]
of the
¡ O r . C C ]
group. The standard default value is
6 % .
The minimum value of the automatic adjustment at low frequencies is the torque
boost setting value [Ub ] of the fundamental group [0 f~. F]. The standard
default setting for parameter
[ U b ]
is 3%.
If the automatic torque boost setting [UbH] is set lower than the initial
starting torque boost [Ub ], then the automatic torque boost is not active at
any output frequency, and the starting torque boost is the only boost present,
and only at lower speeds.