# 128 Voltage



## MotoGP1199 (Aug 11, 2014)

simeon2014 said:


> I know voltage won't typically sit at 120 when reading from voltmeter, however, is 128 volt reading too high from an outlet at a school?
> 
> Panel is 300 feet away. 10 gauge ran to box above and converted to 12s to outlet .
> 
> ...


That's a little higher than what I would see normally but +10%(132 volts) would be in range. What is the voltage at the source feeding those outlets?

If it's the same or higher I would look at the transformer and see if you can adjust the taps. If it's lower you have some investigating to do.


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## Mbit (Feb 28, 2020)

I believe you'd want to reference ANSI C84.1 I could be wrong but here it is: 


Voltage Tolerance Standard – ANSI C84.1 – Voltage Disturbance



With that being said, you could put a small load on it with a wiggy and then put your fluke in parallel for a sanity check. If it's real you could start moving upstream and see where the voltage is going over at. Could the utility.


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## micromind (Aug 11, 2007)

If the service is 480, see what the actual 480 is. 

To get 128, you'd need more than 500 at the service. 

Is the service is closer to 480, you'll need to adjust the taps in the transformer.


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## oldsparky52 (Feb 25, 2020)

Almost as if someone was trying to get 220 between phases.


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