Commander SE User Guide
Issue Number 5
51
Although parameter 38 is defaulted to ‘no autotune’, on the very first power up, Enable
and Run command of the Drive after delivery from the factory, the Drive will initiate a
non-rotating static autotune. After this test, the autotune will be dependent on the value
set in parameter 38. The results of this test will depend on what is connected to the
Drive’s motor terminals.
When default parameters are set (see parameter 29) the first time the Drive is
given an Enable and Run command, a non-rotating autotune will be initiated.
No motor connected
With no motor connected, the Drive will trip on ‘rS’ which indicates a stator resistance
measurement failure. This will be stored in the Drive as zero ohms. The trip can be
reset and the Drive run as normal. If the Drive is powered down and then back up, after
an enable and run signal, it will again perform a non-rotating static autotune and trip
on ‘rS’.
Motor connected but stator resistance higher than allowable value
The Drive will again trip on ‘rS’ if the stator resistance being measured is greater than
the Drive’s internal maximum limit. This can happen if a star connected motor is
connected to a 200V Commander SE or a motor of a lower kW rating is connected to
a larger kW Commander SE. In this case, the Drive will store the maximum allowable
stator resistance for that size of Drive. If the Drive is powered down and then back up,
after an enable and run signal, it will not perform another autotune.
Motor connected but current levels required for successful autotune not reached
The Drive will trip on ‘rS’ if the current levels required to measure the stator resistance
are not reached in the allowable test time. This will be stored in the Drive as zero ohms.
This can occur because a combination of stator resistance and motor voltage prevents
the required current levels being reached. If the Drive is powered down and then back
up, after an enable and run signal, it will again perform a non-rotating static autotune.
The current levels required for a successful autotune are both half and full motor rated
current (parameter 06). Two measurements are taken to ensure accurate results.
Important Notes:
It is important to ensure that the motor wiring configuration is correct (i.e. Star
/ Delta) before performing an autotune.
If any changes are made to the Drive’s motor map parameters, system wiring,
motor wiring configuration or motor type, the Drive must be re-autotuned to
the motor. Not performing another autotune will result in poor motor
performance or OI.AC trips.
Enter the motor rated frequency (taken from motor rating plate).
Defines the voltage to frequency characteristic applied to the motor.
When Auto is selected, the Drive automatically calculates the number of motor poles
of the machine from the settings in parameters 07 and 39. If either of these parameters
are adjusted for a special motor or to modify the V/f characteristic, the automatic
NOTE
NOTE
NOTE
No.
Function
Type
Limitations
Range
Units
Defaults
39
Rated
frequency
RW
U
0 - 1000.0
Hz
50.0
EUR
60.0
USA
No.
Function
Type
Limitations
Range
Units
Defaults
40
No. of
poles
RW
T
Auto, 2P,
4P, 6P, 8P
Auto
EUR
Auto
USA