TDE MACNO MINIOPD EXP User Manual page 20

is enabled with connection C42: this test must be carried out with the motor decoupled from the load.
Failure to do so may invalidate the results.
If the tests cannot be carried out for any reason, these values will have to estimated by reading the
motor plate and following these points:
•
The magnetizing current value is sometimes shown on the motor plate under I
P73 = I / Inom motore. If this value is not available, it will have to be estimated: set P73 to a value
0
that supplies a no-load motor running at rated speed with a three-phase alternate voltage which is
effective but slightly lower than the rated motor voltage. Then change P73 until d18 displays a
value of about 96 - 97% .
•
Once P73 is established, rated torque current P72 can be established as:
•
The rotor time constant (in seconds) can be calculated with the following formula:
1 1 P72
= ⋅ ⋅
Tr
6,28 fs P73
Establish fs by reading the rated slip value, usually in rpm, on the motor plate, then compare it
with the rated speed and multiply everything by the rated motor frequency.
Check P74 by forcing the motor to request a torque current:
- changing the speed reference value brusquely
- applying different loads to the motor
and observing the behaviour of the stator voltage module. If this value is correct, the voltage
should only vary slightly in the transient phase.
These other parameters are not as important and the default values may be left if more reliable data
are unavailable.
This test reads the basic electrical parameters that characterise the induction motor being used so
that it can be modelled according to the rotor magnetic flux. After these values have been
established, the PI regulators in the current and flux loops are self-set .
There are 4 test functions. Each requires a no-load motor, i.e. decoupled from the load, if they
Connection C42 is used to enable these tests. See the table below:
The display will show the following setting according to which tests are enabled:
The drive is now ready to start the test. Start reading by enabling RUN with its digital input and
setting C21=1 (command in series).
Once the tests have started, this setting will appear alongside:
The test finishes successfully if this setting appears the following indicaton and the drive does not
trigger an alarm.
Now disable RUN by setting its digital input to 0 or clearing C21=0.
20
with fs rated slip frequency.
are to function correctly.
C42
0
Only Tests 1 and 2 enabled. Motor does not
1
Only Tests 3 and 4 enabled. Motor needs to be
2
All tests enabled. Tests carried out in quick
3
Test 1 and 2 enabled
Test 3 and 4 enabled
P74 = Tr in milliseconds
Enabled function
No test enabled
need to be rotating.
rotating.
succession.
. In this case,
0
− P73
2 2
100