3 phase voltage

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Might be normal. What % of your load is 3 phase equipment ?
 
Much depends on what was running when you took the measurements. If, for example, you had a single phase instant hot water heater on phase A that was running at full load when you took the readings, and that was not running three minutes later, a second set of readings might be closer to each other.
 
Since all voltages are skewed, a compromised neutral is the prime suspect. Agreed with comparing voltages to ground to those to neutral, and voltage between ground and neutral.
 
johnjohnls.js said:
On a 120/208 3 phase panel im seeing 145 on A. 119 on B. And 95 on C. Any ideas on why?

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Sure it is 120/208 and not 120/240? 145 + 95 = 240, is main reason I ask, lost neutral between those two could give results you have, would think the 119 would likely drift also, but depends on conditions, but one of them should be a high leg in such system. Bottom line be sure what you are supposed to have. Bad neutral seems most likely, could be lost phase as well and motor(s) are generating whatever amount of a third phase you have.
 
iceworm said:
I was curious, so I graphed it - low tech, pen and straight edge on 1/10" paper.
I looks like 208/120 with the neutral displaced ~ 35 volts.
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Probably most likely lost neutral. Lost phase can be regenerated by motors, won't be 100% of what it initially was but should still have reasonably close to 120 volts to neutral on both the remaining good lines.
 
I averaged the three voltage readings and came up with 119. 119*1.73 gives me the expected 207 L-L.
Rounded. Close enough.

Would be nice to know L-L,& N-G voltages.

Could these be Voltages L-Earth for a transformer that does not have its center point properly grounded?
 
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