As far as published standards or “treaties” between utilities and appliance manufacturers in the US, the granddaddy reference is ANSI C84.1-1995, but you have to buy that. An adopted, condensed version {that differs on one entry} for 600-volt systems is ARI Std 110-2002 at
www.ari.org/std/standards.html It is very important to understand that, before placing blame on voltage levels, you have a meter that is known to be accurate—typically having a met-lab sticker less than a year old. Also, understand the potential for published errors of the meter used. For instance, a Fluke 87 on a higher AC-volt range for 60Hz is listed at ±0.7% + 2 counts. So, for a 120V measurement, the acceptable displayed range for that particular “in-calibration” meter could be 118.96 — 121.04V.
Do not confuse resolution with accuracy in electrical measurements with digital meters. Also, operating temperature, battery condition, signal frequency and deviation from a zero-distortion sine wave affect measurement accuracy.
Be aware of the difference between service and utilization voltage, and how the two relate to utilization-equipment nameplate voltage.
[This message has been edited by Bjarney (edited 11-30-2003).]
