DH, Here a copy of what someone wrote in a discussion about this. I wouldn't have known about this hook up myself if I hadn't run into it and had to figure it out to get the lights working again.
Up until somewhere in the 1920's, there was no Code requirement that the lampholder had to have the neutral on the screw shell. One will find examples of this "Carter" 3-way in electrical inspector approved installations from the first decades of the 20th Century.
Many two story homes that were wired with Knob and Tube had lighting on the main stairs that was controlled by a 3-way switching setup.
One of the 3-way switching hookups that was used was this polarity-reversing method.
One brought a hot and a neutral to each switch location and hooked them to the switch traveler terminals, and then sent one wire off to the lampholder from each switch. There was a real economy here, for the installing electrician.
I have found that many times, on little two story homes, that the hot and neutral came from different circuits, on occasion. This is a particular delight to discover on a service upgrade, when one takes one of the two circuits (both should be on the same service leg) and inadvertently puts it on the "other side" of the panel.
When the light should be OFF with both the screw shell and the center button HOT, suddenly, becomes a 240 volt bolted short circuit.
We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]
Today's Featured Article - Field Modifications (Sins of the Farmer) - by Staff. Picture a new Chevrolet driving down the street without it's grill, right fender and trunk lid. Imagine a crude hole made in the hood to accommodate a new taller air cleaner, the fender wells cut away to make way for larger tires, and half of a sliding glass door used to replace the windshield. Top that off with an old set of '36 Ford headlight shells bolted to the hood. Pretty unlikely for a car... but for a tractor, this is pretty normal. It seems that more often than not they a
... [Read Article]
Latest Ad:
Sell 1958 Hi-Altitude Massey Fergerson tractor, original condition. three point hitch pto engine, Runs well, photos available upon request
[More Ads]
All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy
TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.