Most Delco alternators have a minimum cut-in speed of 1200 RPM, but it can vary depending on exactly what regulator is stuck int there. When mounted on auto or truck engines, the engine speed to alternator speed ratio is usually at least 2.3 to 1, but many are up to 4 to 1. Tractors sometimes a litle slower at 1.9 to 1. At 2.3 to 1, and an engine idling at 600 RPM, the alternator is spinning at 1380 RPM.
It can depend on many things and not all alternators are the same, even when the same model #. There are several different regulators that can be installed and all have different cut-in values. Pulley size also changes things.
Some 12SIs and 17SSIs can self-excite with no field current and no self-excite regulator installed, if run fast enough. All depends on the condition of the residual magnetism.
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 - Third Brush Generators - by Chris Pratt. While I love straightening sheet metal, cleaning, and painting old tractors, I use every excuse to avoid working on the on the electrics. I find the whole process sheer mystery. I have picked up and attempted to read every auto and farm electrics book with no improvement in the situation. They all seem to start with a chapter entitled "Theory of Electricity". After a few paragraphs I usually close the book and go back to banging out dents. A good friend and I were recently discussing our tractor electrical systems when he stated "I figure it all comes back to applying Ohms Law". At this point
... [Read Article]
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.
