Background: for the last six months or so, we have been having "over voltage" excursions, i.e. more than 250V AC at the meter. It took me a while to realize that the system response on one of UPS units was caused by it detecting an over voltage situation and going into a protective mode to reduce the voltage. Meanwhile, Tesla support had noticed some "over voltage" codes on the Powerwalls and let me know.
We normally have line voltage in the higher end of the spectrum, something I had put down to being rural, and in a branch circuit that goes 35-50 miles or so. Before we had solar, our line voltage at the meter ran about 248V most of the time. In the past, solar might have pushed it up a volt or so, but not more. A series of things have occurred over the last year;
The utility inspector was out today on a call from me on the higher voltage, and the inspector was of the opinion that it was being caused by solar. I flipped the main breaker, and the voltage at the meter dropped from 253 to 250V. The inspector was of the opinion that perhaps we might need a larger service drop and/or a larger transformer, to lower the impedance, and planned to bring the issue up with engineering. Reducing the impedance would drop the voltage needed to get our exports back on the grid, so that made sense to me.
The follow up several hours later is that the utility had found a second customer, also having voltage issues. They took a local capacitor bank offline and seem to have resolved the issue, at least for the moment.
Has anyone seen anything like this? Does any of this make sense?
Thanks!
BG
We normally have line voltage in the higher end of the spectrum, something I had put down to being rural, and in a branch circuit that goes 35-50 miles or so. Before we had solar, our line voltage at the meter ran about 248V most of the time. In the past, solar might have pushed it up a volt or so, but not more. A series of things have occurred over the last year;
- A neighbor finally got PTO (after 27 months, due to their installer messing up). 12kWDC
- A second neighbor installed about 6kW DC solar.
- All of the thirty or so neighbors on the same branch medium voltage line got new transformers, almost all the same exact model. (As far as I can tell.)
- The utility meter reports highly variable power exports
The utility inspector was out today on a call from me on the higher voltage, and the inspector was of the opinion that it was being caused by solar. I flipped the main breaker, and the voltage at the meter dropped from 253 to 250V. The inspector was of the opinion that perhaps we might need a larger service drop and/or a larger transformer, to lower the impedance, and planned to bring the issue up with engineering. Reducing the impedance would drop the voltage needed to get our exports back on the grid, so that made sense to me.
The follow up several hours later is that the utility had found a second customer, also having voltage issues. They took a local capacitor bank offline and seem to have resolved the issue, at least for the moment.
Has anyone seen anything like this? Does any of this make sense?
Thanks!
BG