stevenal wrote:
ktmrfs,
And I continue to spend my life in the power delivery industry. Our bible is ANSI (American National Standards Institute) C84.1 when it comes to voltage. It spells out two ranges A and B, with A being the range to meet the majority of the time. Each range includes service voltage (what we care about) plus utilization voltage (at the receptacle.) None of this works out to 10%, but can be approximated by 5 at the service. If your electronics meet a wider range, that's good. Maybe an excursion into range B won't kill them.
I see you are in Portland. Perhaps you've heard of PGE.
https://www.pge.com/includes/docs/pdfs/mybusiness/customerservice/energystatus/powerquality/voltage_tolerance.pdf
The NEMA standard is +/- 10, but starts at 115 nameplate instead of the 120 nominal used by ANSI.
probably a case of source tolerance spec vs. equipment tolerance voltage spec. With the ANSI source tolerance A & B and a 10% equipment tolerance pretty much assured equipment will operate with source tolerances at the limit along with unexpected drops in the wiring system, especially when it comes to the low voltage end where most equipment runs into trouble.