that in parameter 120
Start delay
a time is set, and that
a reference signal is present.
132
DC brake voltage
(DC BRAKE VOLTAGE)
Value:
0 - 100% of max. DC brake voltage
0%
Function:
In this parameter, the DC brake voltage is set which is
to be activated at stop when the DC brake frequency
set in parameter 127
DC brake cut-in frequency
is
reached, or if
DC braking inverse
is active via a digital
input or via serial communication. Subsequently, the
DC brake voltage will be active for the time set in pa-
rameter 126
DC brake time
.
Description of choice:
To be set as a percentage value of the max. DC brake
voltage, which depends on the motor.
133
Start voltage
(START VOLTAGE)
Value:
0.00 - 100.00 V
Depends on unit
Function:
A higher start torque can be obtained by increasing the
start voltage. Small motors (< 1.0 kW) normally require
a high start voltage.
Description of choice:
The factory setting will be suitable for must applica-
tions, the value may need to be increase gradually for
high torque application.
Warning: If the use of start voltage is ex-
aggerated, this may lead to over-energiz-
ing and overheating of the motor and the
frequency converter may cut out.
134
Load compensation
(LOAD COMPENSATIO)
Value:
0.0 - 300.0%
100.0%
Function:
In this parameter, the load characteristic is set. By in-
creasing the load compensation, the motor is given an
extra voltage and frequency supplement at increasing
loads. This is used e.g. in motors/applications in which
there is a big difference between the full-load current
and idle-load current of the motor.
NB!
If this value is set too high, the frequency
converter may cut out because of over-
current.
Description of choice:
If the factory setting is not adequate, load compensa-
tion must be set to enable the motor to start at the given
load.
Warning: Should be set to 0% in connec-
tion with synchronous and parallel-cou-
pled motors and in the case of quick load
changes. Too high load compensation
may lead to instability.
135
U/f-ratio
(U/f RATIO)
Value:
0.00 - 20.00 at Hz
Depends on unit
Function:
This parameter enables a shift in the ratio between
output voltage (U) and output frequency (f) linearly, so
as to ensure correct energizing of the motor and thus
optimum dynamics, accuracy and efficiency. The U/f-
ratio only affects the voltage characteristic if a selec-
tion has been made of
Constant torque
[1] parameter
101
Torque characteristic.
Description of choice:
The U/f-ratio is only to be changed if it is not possible
to set the correct motor data in parameter 102-109.
The value programmed in the factory settings is based
on idle operation.
= factory setting, () = display text, [] = value for use in communication via serial communication port
74
MG.27.E2.02 - VLT is a registered Danfoss trademark
