Load Compensation - Danfoss VLT 2800 Series Operating Instructions Manual

Description of choice:
To be set as a percentage value of the max. DC
brake voltage, which depends on the motor.
133 Start voltage
133
(START VOLTAGE)
Value:
0.00 - 100.00 V
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 exaggerated, this may lead to over-
energizing and overheating of the motor
and the frequency converter may cut out.

134 Load compensation

134
(LOAD COMPENSATIO)
Value:
0.0 - 300.0%
Function:
In this parameter, the load characteristic is set. By
increasing the load compensation, the motor is given
an extra voltage and frequency supplement at
increasing loads. This is used e.g. in motors/applica-
tions 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 overcurrent.
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.A5.02 - VLT is a registered Danfoss trade mark
VLT
Description of choice:
If the factory setting is not adequate, load compen-
sation must be set to enable the motor to start at the
given load.
load changes. Too high load compensation may lead
to instability.
Depends on unit
135 U/f-ratio
135
Value:
0.00 - 20.00 at Hz
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 selection 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 possi-
ble to set the correct motor data in parameter
102-109. The value programmed in the factory set-
tings is based on idle operation.
136 Slip compensation
136
Value:
-500 - +500% of rated slip compensation
Function:
Slip compensation is calculated automatically , on the
basis of such data as the rated motor speed n
100.0%
this parameter, the slip compensation can be fine-
tuned, thereby compensating for tolerances on the
value for n
selection has been made of Speedregulation, open
loop [0] in parameter 100 Configuration and Constant
torque [1] in parameter 101 Torque characteristic.
®
2800 Series
Warning: Should be set to 0% in
connection with synchronous and parallel-
coupled motors and in the case of quick
(U/F RATIO)
(SLIP COMP .)
. Slip compensation is only active if a
M,N
Depends on unit
100%
. In
M,N
21