Technical data

VLT 5000/5000 FLUX SyncPos Quick-Setup

MG.10.Q1.5B – VLT is a registered Danfoss trade mark16

... the tolerated position error is exceeded

If the test run is constantly interrupted with the

message “position error” set the parameter for

the

olerated position errorolerated position error

olerated position error POSERR (15) –

within the tolerable limits– as large as possible.

If the position error occur during the acceleration

phase that suggests that the set acceleration

cannot be achieved under the existing load

conditions. Increase the

olerated position errorolerated position error

olerated position error

POSERR (15) or determine a maximum

acceleration suitable for the entire system.

If position error do not occur until after the acce-

leration phase and they can be delayed but not

eliminated by increasing the

olerated positionolerated position

olerated position

errorerror

error

, this suggests that the maximum velocity

(rpm) chosen is too high. Determine a maximum

velocity suitable for the entire system.

.. the maximum acceleration is not achieved

In general, the technical data for a drive are only va-

lid for a freely rotating axle end. If the drive is carry-

ing a load the maximum acceleration is reduced.

The theoretical maximum acceleration will also

not be achieved if, for example, the PID controller

output is too small or the VLT/motor is not sized

correctly and therefore does not provide enough

energy for peak consumption during acceleration.

10 steps to optimise the PID loop