On 01/01/2016 01:02 PM, John Thornton wrote: > So tie say the 48v side to ground to create the neutral? I attached the > drawing of what I have so far on the VFD side.
No, then you just short a capacitive path to ground. If you have no neutral, then you do not have it. All voltages you measure wrt. ground are relative values and are influenced by the induced phase angle of whatever you have on the lines wrt. ground. The ground line will be floating due to capacitive couplings and it may not be entirely symmetric from the phases L1 and L2. Therefore, if you mesaure wrt. ground, you see differences in the RMS voltage. The multimeter is no real load and will not influence the phase angle of any capacitive coupling. However, note that such measurements do not represent the the voltages you have at your displosal for the loads. There are in principle only two voltages you can measure: - input lines between L1 and L2 -> ~240V - after the transformer at the output of the transformer -> ~120V These are the only voltages that make sense to measure. There is one remaining measurement that you should do: Measure the DC resistance between the chassis and the protective ground of the wall-outlet. That should be close to zero. Then, assuming that the wall-outlet's ground is properly connected, you have assured that you actually have a protective ground connected to your equipment. -- Greetings Bertho (disclaimers are disclaimed) ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
