Another one of those fascinating "threads!" I have lived through the claimed 110, 117 and 120 volt periods and have been apparently lucky enough to not have suffered any device damage. At present I live on a hill and do worry about lightning strikes to ham radio antennas. The last time I counted I had over 20 standard eight foot plated ground rods driven at various places and the entrance point of these antennas to the house is protected by an additional 6 rods. All wiring in the house is either thin wall tubing or other armored cable. Thus I effectively have building perimeter protection as well. All grounds are tied together along with the power neutral. I also have an automatic transfer backup alternator with separate ground also tied to the entire system. I do disconnect antennas during storm threats but in the past thirty years have yet to have any "over voltage" damage. From time to time I do check the line voltage but not with any NBS standard voltmeter and have found that it does "drift" between 120 and 126 which I feel is outstanding given the general circumstances which include being several miles from the distribution point along a rural road and the possibility of some fairly demanding motor starting loads that I deal with. My input panel is over 200 ft. from the farmer's electric co-op transformer which I used to share with two neighbors but now I have "my own." Yes, I do have lightning rod protection.
73 Lee K9WRU ----- Original Message ----- From: Poul-Henning Kamp <p...@phk.freebsd.dk> To: Discussion of precise time and frequency measurement <time-nuts@febo.com>, Chuck Harris <cfhar...@erols.com> Sent: Mon, 02 Jan 2017 12:55:58 -0500 (EST) Subject: Re: [time-nuts] Line Voltage - USA -------- In message <586a8b40.4050...@erols.com>, Chuck Harris writes: >Back in the dark ages of ~220V electrical distribution systems in >Europe, the reaping due to unintentional grounding of a ~220V wire >was so common and extreme, whole house ground fault interrupters >were mandated for all residential/small business power systems >therein. Close, but no cigar. The main problem was that in many countries outlets did not have a protective ground terminal. That meant that an internal fault in your appliance had a 50/50 chance of lighting up some exterior metal part you could touch. The "obvious solution" isn't obvious in countries where the geography does not allow you to obtain proper "protective ground". Norway being a good example. But even countries with the "obvious solution" of protective ground in all outlets saw problems, because it took 10-16 ampere misdirected current to blow the fuse, and you can light most flameable stuff with a lot less energy than that. The "Residual Current Device" solved both problems. RCD's even protect you from internal faults where proper protective ground is not available, by providing neutral from "outside" the RCD as PG in the installation. You'll still be (horribly!) exposed of an accident in the distribution grid (or lightning!) fires up the neutral, but that's simply life - or death - without a grounding rod. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
