Secondary 480-240 Delta-Delta voltages
Secondary 480-240 Delta-Delta voltages
(OP)
Hi!
I have an application whereby I'm using a 3-phase 480-240 transformer to power a Variable Frequency Drive (VFD) for an AC motor, using the secondary 3-phase 240 VAC of the transformer for the Drive's power connection. However, since the secondary of the transformer is connected as Delta, I'm not only seeing 240 volts AC phase-to-phase, but also voltages of 100, 150 and 170 from each phase of the secondary to the ground connection of the VFD. Should I be concerned of these phase-to-ground voltages, or will the VFD just be looking at the 240 volt potential between each of the phases? Thanks!
Bill K.
I have an application whereby I'm using a 3-phase 480-240 transformer to power a Variable Frequency Drive (VFD) for an AC motor, using the secondary 3-phase 240 VAC of the transformer for the Drive's power connection. However, since the secondary of the transformer is connected as Delta, I'm not only seeing 240 volts AC phase-to-phase, but also voltages of 100, 150 and 170 from each phase of the secondary to the ground connection of the VFD. Should I be concerned of these phase-to-ground voltages, or will the VFD just be looking at the 240 volt potential between each of the phases? Thanks!
Bill K.






RE: Secondary 480-240 Delta-Delta voltages
However! General wisdom is to avoid running drives on ungrounded sources. Most are designed for use on a solidly grounded supply; unpredictable and generally bad things can happen when used on other supplies. See what the drive manual says about supply characteristics, or call the OEM tech support.
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