Form 26S utility meter

[aelectricalman]

I have wired a form 26S meter "the correct way" according to the manual however, I am getting 166 V on A phase and 345 V on C phase. If a form 26S is a delta configuration, why Im I getting a voltage imbalanced reading. Do I have to have PT's to get a reference to ground, to make this combination work? Goes against the logic of why I'm metering with a 26S doesn't it? Any help would be greatly appreciated. See attached configuration.

 

[aelectricalman]

The guy with company where I purchased the meter said, " Oh that's not a problem, just drive a ground rod and get your ground ref that way." [What the what?] I don't think I will. This is a 480V delta system. The meter is at 480V phase to phase.

 

[GoldDigger]

The guy with company where I purchased the meter said, " Oh that's not a problem, just drive a ground rod and get your ground ref that way." [What the what?] I don't think I will. This is a 480V delta system. The meter is at 480V phase to phase.

The fact that there is a lead identified as N shown and it is part of the potential coil input makes me uncomfortable with this working for Delta rather than wye.
Do you have a corner grounded delta? An ungrounded delta? Or a wye source with no access to the neutral?

 

[aelectricalman]

The fact that there is a lead identified as N shown and it is part of the potential coil input makes me uncomfortable with this working for Delta rather than wye.
Do you have a corner grounded delta? An ungrounded delta? Or a wye source with no access to the neutral?

This is an ungrounded delta configuration. The utility company here does not use form 5S meters on ungrounded deltas, they only use form 26S. So based on what you are telling me it almost sounds like we need to find a way to reference ground (IE...PT's). I don't understand why the utility would go through that expense of adding PT's when its not necessary for proper metering (when a 5S is available). Do you see this any other way?

 

[Bugman1400]

This is either a bad metering design (not the meter) or the wiring for the meter base is not complete. Since you have just the two phases of voltage and current then it seems your N should be somehow connected to Phase B.