VS65 SERIES MV SOFT STARTER
POWER ELECTRONICS
38
CONFIGURATION, LOW VOLTAGE TRIAL AND COMMISSIONING
8.2.
Low voltage Trial
CAUTION
Only qualified personal can make this test.
Otherwise, the equipment can be damaged and you may suffer electric shocks.
After treat all the things explained before, it is necessary to perform a low voltage test to allow the
personnel check soft starter’s electric configuration safely and in which test makers don’t need special
tools.
The VS65 is able to start and stop a low voltage three-phase motor, using only a low voltage transformer
connected instead of the medium voltage transformer.
This test will be first made in the Power Electronics facilities, where the test conditions can be simulated.
After, in the customer installation, it will be necessary to repeat the same test before connecting the soft
starter to the medium voltage network. Power Electronics qualified personnel must always make this test.
8.2.1.
Material
The following tools are needed to perform the low voltage test:
A low voltage 400/110VAC, 2kVA for soft starters with a rated voltage of 6000V or
more, or a low voltage 400/70VAC, 2kVA for soft starters with a rated voltage of 4160V
or less (approximately) three-phase transformer connected in configuration star-star
with phase angle 0º. A second alternative could be to use two single-phase
transformers with the same characteristics as in the following image.
Figure 8.1 Low voltage test transformer
•
Three 300k
Ω
/ 6W resistors (one per phase).
•
Three test bulbs of 100W and 230VAC with star connection as it is shown in the
following figure. The terminals U, V and W will receive 400VAC when the equipment is
connected to this voltage and started.
Figure 8.2 Connection of the test bulbs
•
One low voltage three-phase motor from 1 to 10CV.