This test is done using a digital multi-meter in diode test mode to check that the transistors and
diodes are not short-circuited. The absolute values are not so important because they depend
strongly on the test device. However, in function of each module, it is possible to find values include
in like indicate the following schematic. The uniformity of the measured values is more important.
Please further note, that the drives requires some time to load the intermediate circuit capacity.
There are 24 measurements to be made:
Checking the thyristors of the input bridge:
(Only for drives > 15KW 230V, P > 18.5kW 480V, and 690V range up to 90kW)
This test is done using a multi-meter in the ohmmeter position to check that the thyristors are not
short-circuited. The test is done like the preceding test between PO and L1, L2, L3.
Checking of the thyristor module only:
This test is done using an incandescent lamp and a 4.5 V battery connected. Using the schematic
below.
Switch open ⇒ the thyristor is in open circuit (lamp off).
Close the switch ⇒ the thyristor conducts (lamp on).
Open the switch ⇒ the thyristor remains conductive (lamp on).
Lower the voltage to turn off the thyristor.
If the operation is different than described, the thyristor is probably out of service.
diodes are not short-circuited. The absolute values are not so important because they depend
strongly on the test device. However, in function of each module, it is possible to find values include
in like indicate the following schematic. The uniformity of the measured values is more important.
Please further note, that the drives requires some time to load the intermediate circuit capacity.
There are 24 measurements to be made:
Checking the thyristors of the input bridge:
(Only for drives > 15KW 230V, P > 18.5kW 480V, and 690V range up to 90kW)
This test is done using a multi-meter in the ohmmeter position to check that the thyristors are not
short-circuited. The test is done like the preceding test between PO and L1, L2, L3.
Checking of the thyristor module only:
This test is done using an incandescent lamp and a 4.5 V battery connected. Using the schematic
below.
Switch open ⇒ the thyristor is in open circuit (lamp off).
Close the switch ⇒ the thyristor conducts (lamp on).
Open the switch ⇒ the thyristor remains conductive (lamp on).
Lower the voltage to turn off the thyristor.
If the operation is different than described, the thyristor is probably out of service.