PWs and mini-split voltage

[zƬesla]

My outdoor Mitsubishi mini-split unit got a firmware upgrade and (unrelated) the tech mentioned they are seeing lots of issues with them as a result of over voltage (>240).

Has anyone encountered this?

Does having solar and Powerwalls in any way help with the situation, or is the voltage reaching the unit set by the grid?

Is the voltage reading available via the PW gateway API or do I need to use a Kill-a-Watt?

Thanks!

 

[GregBallantyne]

There is a product that monitors your household voltage 24/7. Perhaps there are many, but I recently got one from State Farm, my homeowner insurance carrier. The aim is to identify problems early before an electrical fire develops. The product is called Ting. It plugs into an outlet connected to your household wiring and monitors via constant sampling. The results are viewable via the app, which shows a graph of voltage. I'm not sure about 240 vs. 120, my results show a supply range mainly between 110 and 116 volts, with the occasional momentary lower excursion that so far has not gotten as low as 105. The Ting plugs into a 120V circuit.
I am assuming that monitoring a 240V circuit during the same period would simply show double what this thing is reporting.

Bottom line, with respect to your question, since receiving and using this Ting monitor (not quite 2 weeks) my household has been powered 100% by my Tesla Solar Roof and/or Powerwalls. The monitor hasn't been exposed to grid power supply yet. There has been no indication to date that the system has supplied an overpowered condition, or quite as high as 240V using my previous assumption. My PWs are PW2.
Anecdotal I guess, but maybe helpful.....

 

[BGbreeder]

My outdoor Mitsubishi mini-split unit got a firmware upgrade and (unrelated) the tech mentioned they are seeing lots of issues with them as a result of over voltage (>240).

Has anyone encountered this?

Does having solar and Powerwalls in any way help with the situation, or is the voltage reaching the unit set by the grid?

Is the voltage reading available via the PW gateway API or do I need to use a Kill-a-Watt?

Thanks!

The voltage is set by a combination of the grid, and the house load (import/export). Mostly, the base value is set by the grid. As the house imports power, there will be some voltage drop depending on the load, and your particular site (e.g. service drop resistance, transformer impedance), and similarly, as your system exports power, the voltage will go up. As your neighbors import/export their home loads/exports will push your local voltages around.

Bottom line, your utility should arrange to keep power within its "norm", and generally that is 252VAC maximum. I was having issues with overvoltage errors, and the local utility removed a capacitor bank that brought the line voltage back to a reasonable level.

Power quality issue: possible causes?

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...

teslamotorsclub.com

It is easy to check; if you check the split phase 120, be sure to check the other phase as well; imbalances can and do happen.

All the best,

BG