12v for dummies

[VanKitten]

I have read through the simple wiring here (Bobs how to)

What I need is a 12v wiring for dummies.

I cannot do the Ebook thing.   Most of the time during the day I have no wifi...so an online book cannot be my guide.

Anyone know of a good "dummies" level book out there in hardcover?

I am about to start the wiring.   I am stuck on wiring gauge.   If I do it all in 10 gauge...is that ok.   Good for fridge and lights.   I realize it might be over kill...but is that important?

The longest run I will have is 20 feet....do I even need to think of power loss over that short a distance?  

If I sound dumb..it is because I am.

 

[galladanb]

Good questions! It's as if you read my mind!!!!

Thx. Following along with ya!

 

[jonsun]

it can be ok yes. theres plenty of voltage drop calculators online.

the most important thing is the charger to the battery and you have 2 options. 1 use 10awg but do it with a sense wire so the controller will adjust itself. or 2 use 8 or 6.

 

[VanKitten]

Yes...I see the voltage drop calculator ... I just don't understand what it means.

Is there more voltage drop with larger gauge. Does AWG mean gauge?

This beginning is just the "rough in" wiring. I know where everything will go...so I am getting ready to string the wiring over the ceiling to the "kitchen" which will be located opposite side from battery, electric panel, etc.

I am also guessing that the fuse box can be in the same cabinet with all the rest of the elect. Basically near to the battery.

Yeah..basic questions. I need a book

 

[jonsun]

bigger number = smaller wire = MORE voltage drop

bigger wire = better (i.e. 8awg, 6awg)

sorry dont know of a book

 

[Optimistic Paranoid]

AWG stands for American Wire Gauge.  Bardo is right, the bigger the number, the smaller the wire.  In your house, I  believe the code calls for 12 gauge wire for 15 amp circuits, and 10 gauge wire for 20 amp circuits.  Common wiring runs from about 22 gauge up to 0 gauge.  And there are even bigger wires - 2/0, 3/0, and 4/0 used for things like arc welding cables.  Your computer may contain even smaller wire, like 28 gauge, 30 gauge, etc. which only carry small voltages used for control, rather than power.

Maximum SAFE  continuous current allowed on standard wires is:

12 gauge = 10 amps
10 gauge = 15 amps
8 gauge = 25 amps
6 gauge = 40 amps
4 gauge = 60 amps
2 gauge = 95 amps
1 gauge = 120 amps
0 gauge = 150 amps
2/0 gauge = 195 amps
3/0 gauge = 240 amps
4/0 gauge = 300 amps

That's with all wires separate so there are no cooling issues.  If wires are bundled together so the inner wires can't be cooled, they need to "derated" for less current.  The cable from your battery to your starter is probably 4 gauge, and it certainly carries more than 60 amps, but only for 10 to 30 seconds, so it never has a chance to overheat.

If you get a big inverter, you'll be using 0 gauge or bigger to run power to it.

As far as books go, I taught myself pretty much everything I know from the following books.  Your local public library can probably get any or all of them for you via inter-library loan.  The book on automotive wiring is the one to learn nuts and bolts of working with wires.

https://www.amazon.com/Automotive-W...id=1486393394&sr=1-2&keywords=auto+electrical

https://www.amazon.com/Managing-12-...UTF8&qid=1486392253&sr=1-1&keywords=rv+wiring

https://www.amazon.com/No~Shock~Zon...rd_wg=R2qP6&psc=1&refRID=YQQPRBVGDBPQ1G7PZP2G

https://www.amazon.com/Electrical-S...UTF8&qid=1486392253&sr=1-2&keywords=rv+wiring
https://www.amazon.com/Electrical-S...UTF8&qid=1486392253&sr=1-2&keywords=rv+wiring

 

[blars]

That table is way off for even 85C copper wire, let alone 105C wire. 14AWG is used for 15 amp house circuits, 12AWG for 20 amp, 10AWG for 30 amp. That's romex, derate in packed conduit. (The temperature rating of the insulation matters, 85C and 105C are common.)

Voltage drop is the reason to use bigger wire in 12v circuits, not safety.

 

[Optimistic Paranoid]

That table is way off for even 85C copper wire, let alone 105C wire.  14AWG is used for 15 amp house circuits, 12AWG for 20 amp, 10AWG for 30 amp.  That's romex, derate in packed conduit.  (The temperature rating of the insulation matters, 85C and 105C are common.)  

Voltage drop is the reason to use bigger wire in 12v circuits, not safety.

I don't remember where I got those figures from.  I do know different web sites don't all agree on the numbers.

 

[mayble]

I'm hoping for a picture book :s
I don't know if it's ADD + age or just plain laziness, but I have a hell of a time digesting anything I read anymore.  I can't even get through a paragraph before my mind starts to wander.

 

[WalkaboutTed]

Sailboat Electrics Simplified
By Don Casey
from Amazon, $17.75
58 reviews, 4.6 stars rating

Everything has pictures and diagrams for the visual learner.

Enormously helpful. Also, because it's based on tougher maritime conditions (i.e, salt and/or water exposure), he opines more strict specifications for the work, vs automotive.

The only caveat is that it was published in 1999, before the widespread use of LEDs and other energy usage innovations. But 12 volt is 12 volt, that doesn't change. There is also discussion and instructions about solar, wind generators, AC, coaxial, how to do mapping and schematics, alternator/regulator wiring, battery hygeine, inverters, shore power and even how to use a multimeter. The only thing we don't have to worry about is grounding to the hull. And very good pictures and diagrams. Lots of details for the novice.

There used to be "The 12 volt Bible", but I couldn't find it. This book is great.
Ted

 

[WalkaboutTed]

I just looked-I must have missed it, but "The 12-volt Bible for Boats" is on Amazon. The reviews aren't as good as the Sailboat Electrics Simplified, but last time I saw the 12 volt Bible was in the 1980s, when I was living aboard and a commercial fisherman. It seemed like a very good book at the time. Now I'm dating myself. Not in the good way.

 

[VanKitten]

I found the 12V bible at various marine stores....is that what you mean? Do you recommend it?

I am going to order that book from amazon today. THANK YOUQ

 

[VanKitten]

Just ordered both

Thanks again

 

[DwelledLongAgo]

I found the 12V bible at various marine stores....is that what you mean?   Do you recommend it?

I am going to order that book from amazon today.   THANK YOUQ

This one looks interesting and informative: THE 12 VOLT DOCTOR'S. PRACTICAL HANDBOOK

 

[VanKitten]

Trouble is I don't usually have wifi during the day when I need the book.

 

[John61CT]

Learn how to download stuff and view/listen/watch while offline

 

[Jlowell]

Trouble is I don't usually have wifi during the day when I need the book.

If you are wanting to buy and read some of the ebooks talked about here, then your in luck.
Goto Amazon.com and do a search for "kindle". Download it to your tablet, phone and computer. It is free. Then you can buy and download the ebooks that are being recommended on here, and read them at your leasher. Or try a sample and then if it is something you want, then buy and download it, or not.

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