... Featuring the books written by ... DALE LEE SUMNER

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Informative Books for RV Enthusiasts & "the Forgotten Marines" - a novel

A company that sells educational books on RVs

SUMDALUS-USA is a Veteran Owned and Operated Company

"Non sibi sed patriae"

Interested in learning  how  "things" in a recreational vehicle actually work?   At SUMDALUS-USA, we offer down-to-earth, educational books about RVs that tell you  everything the owner's manuals DO NOT - and a great deal more!  

Please click through to order yours, today.  

Our Books are written for all RV enthusiasts, especially those who are:

  • initially "CONSIDERING" RVing;
  • just "BEGINNING" their RVing expereience;
  • have been "CAMPING" for years;  or 
  • living the dream of "FULL-TIMING."

AND . . . our books are EASY to read !!

Worried about Techno-Jargon that you won't understand?

Relax!   Dale’s writing style is educational, yet casual and entertaining. 

All topics, in each book, are written in an uncomplicated, nontechnical fashion 

so every reader can easily become familiar with the subject(s).

* * WELCOME * *

There's much to see here.  So, please,  scroll down, look around, 

and discover what our books are all about.  We hope you appreciate 

our site and will take a moment to drop us a line or place an order.

Please be advised:  Our website is best viewed via a PC or MAC.

Many have asked -- The name of our company is ancient Latin.

It is pronounced as "soom daaˊ lus"

Thank you for stopping by.  Enjoy your visit.

Understanding Your RV's "SHORE POWER"


 Ξ  120 Volt Electricity  Ξ   (4th Edition)

Learn the basics of 120 VAC and why it seems to function differently in an RV than it does in a house.  Discover the dangers of plugging your RV into any outlet, as well as the significant fire hazard of "Adapting Up/Down" to plug "in."  Become familiar with the menacing Wiring Faults at the "post" (Open Ground, Accidental 240 Volts, Reverse Polarity, & Open Neutral), along with damaging High/Low Voltages; and how each one can dramatically affect your RV.  Find out what a “SURGE” really is.  Explore what “Whole RV, Electrical Protection Units” are all about.  And much, much more...

Paperback: 104 pages

Language: English

ISBN-13: 978-0-9974634-1-5

Product Dimensions: 9" x 6" x 0.2" 

Now available as a Printed or Digital Book!

Understanding Your RV's "APPLIANCES"


 Ξ  Refrigerator, Furnace, Water Heater, and Rooftop Air Conditioner  Ξ 

 (4th Edition)


Learn how these RV “unique” (you won't find them anywhere else) appliances really work.  Discover why these RV appliances are NOT the same as your familiar house appliances, even though they provide similar results.  Become familiar with each individual appliance's “sequence of operation.”  Explore lots of "tips and tricks" on how to help your RV unique appliances work more efficiently and survive longer.  (Especially, the real answer to preventing the build-up of “fin” ice in the refrigerator!)  Find out why annual maintenenace/service is so important.  And much more...

Paperback: 80 pages

Language: English

ISBN-13: 978-0-9974634-2-2

Product Dimensions: 9" x 6" x 0.2"

"APPLIANCES" - $16.65

Understanding Your RV's "HOLDING TANKS"


 Ξ  Bio-Waste Management  Ξ   (2nd Edition)

Learn what you don’t know about your holding tanks.  Discover the six secrets to obtaining and maintaining odor-free and healthy holding tanks. Find out why most tank treatments don’t really work.  Become familiar with the seven items necessary to safely "dump" the tanks.  Explore how to promote biology and physics to work in your behalf, instead of their normal opposition in your holding tanks.  Understand the necessity of professional (Hydro-Jet) tank cleaning and how often to have it done.  And much more...

Paperback: 84 pages

Language: English

ISBN-13: 978-0-9974634-3-9

Product Dimensions: 9" x 6" x 0.2"

"HOLDING TANKS" - $16.65



- A Vital Record of My RV's Equipment & Appliance Information - 

 * NEW! *    

A concisely laid-out logbook for self-recording all the manufacturer's Product Label data of the repairable equipment and appliances on, in, and under your RV.

Paperback: 96 pages

Language: English

ISBN-13: 978-0-9974634-4-6

Product Dimensions: 9" x 6" x 0.2"

Please see our BLOG article:  Why every RV owner needs a copy of My RV LOGBOOK,” for more information.

My RV "LOGBOOK" - $13.50