If you get voltage readings from phase to ground does this automatically mean you are working on a grounded system? I’m setting up a VFD drive and one of the parameters is to select if it is connected to a grounded system. So how would you classify the system? Here’s what is present:
30KVA delta-delta transformer (buck-n-boost)
Primary is fed from 3 phase 208/120 system.
Secondary is 440VAC 3 phase, no corner or center tap ground (ohmmeter readings are infinity from each phase to ground).
Actual readings on secondary are:
A-B=444V A-GND=239V
A-C= 442V B-GND=271V
B-C=443V C-GND=250V
Actual readings on primary are:
A-B=210V A-GND=121V
A-C=210V B-GND=122V
B-C-209V C-GND=121V
