START HERE Electrical Considerations when building a trailer

[sdtripper2]

Electrical Considerations when building a trailer:
Edited by Steve (sdtripper2)

Preamble

Electrical Decisions for the new builder can seem overwhelming for some.
This document will give you a brief overview answering many of the
beginning questions with the use of some pictures.
Note: The information here of manufactures & products is opinion only, there may be
better products on the market that you may find.

The first question that you might consider: Do I even want any power
in my trailer? The flow of conversation on many threads of the past go
like this. Ask yourself where will you be using your trailer? Is the cost
of putting in the wire uP front while you are building justified in case you
want power at a future date? Will I want a 12 volt system and or a 120
Volt system in my trailer build? Most experienced people here would
council you to have both power sources. It will be cost effective and
possible options for using power may not seem apparent at first. The
time and cost you put into installing both power solutions is well spent.
Did I mention that you might get the real bug and want to build another
trailer? If so and you sell your first trailer it will sell better if it has both
power sources.
AC vs DC thread
***

This document is laid out as follows:

1) Power flow (120 volt) from the camp ground hookuPs to the inlet of the trailer is shown
and discussed first. You will be see quotes and pictures plucked from past threads here.

2) Discussion of trailer wiring inside and the use of a power panel and or using a a GFCI circuit:

3) Choosing a battery and discussing chargers, inverters and converters:

4) Solar Power & Controllers:

5) Useful Tools & Charts:

Note:(link Ref.) is used to point to a thread where a picture or solution
is discussed.
***

Start:
1) Power flow (120 volt) from the camp ground hookuPs to the inlet of the trailer

Question:
Many people ask what is the power panel like at campgrounds?
What side of my trailer should I have power come into when I
make my inlet connection?

Answer:
See what the power panels at campgrounds look like here
Campgrounds have 15- 20 amp, which is the standard household plug. they also have 30 amp, and a 50 amp twist lock, all 110-120 Volt. With an A/C installed (5000 btu) most trailers are not going to pull more than 15 - 20 amps. Unless you really load up on the electrical side. I just would not cheap out on the shore power cord.

1) 15-20 Amp 110-120V
2) 30 Amp 110-120V
3) 50 Amp 110-120V

More details on RV recepticals and 120V 20,30,50 Amp service available at most campsites here:

The inlet power receptacle to your trailer should be on the left side looking from the rear of your trailer or drivers side of the tow vehicle. This is the way the big RV manufacturers do it so why buck the trend. Most here do it that way although there are exceptions. The power panels at campgrounds most likely will be on the driver side rear of the lot as you back in:

Question:
How can I be sure the power from the campground is wired correctly
and there are no grounding issues?



Answer:
Carry an inexpensive tester that you can get at Home Depot or other shops.
This yellow tester isn't for GFCI testing.
You will use this tester to verify the campground plug at their power
panel is wired correctly.

Question:
How can I be sure the power from the campground is wired correctly
and there are no grounding issues especially testing for GFCI?

Answer:
GFCI Tester that might be carried to test shore power before
you hookuP to the your trailer:

GFCI explanation by Bruce:


DO It yourself Step By Step instructions for GFCI plug instillation

Question:
What gauge and type of power cable should I use from the campground
power panel to the trailer?

Answer: You can get a 120 volt male to female outdoor power cable in the gauge
that will match the internal wiring of your trailer or larger as you may feel
the need to have a larger gauge wire come to your inlet circuit to
accommodate the long length of cable.
(More on internal gauge wire later)
Shore power cord length?

Question:
Should I have any adapters to go with the cable?

Answer:

http://tinyurl.com/3275c7
You could have a 30A adapter plug shown here from Camping world
or Walmart. If the power at the campground is ONLY 30 amp service
for some reason your 15 amp outlet at the site has bad magic
you can use this adapter to get power from another circuit at the panel.

Question:
What and where can I get an inlet power receptacle for my trailer?

Answer:

Google search "Charger Inlet" or "Shore Power Inlet"
Different Inlet power receptacles here
Vintage Trailer Aluminum look Inlet Power receptacle
There are many solutions and inlet receptacles that you could use.
I have shown two here but read the accompanying threads to get more
Ideas. Some will be covered and have space for inlet connections for
cable TV. The basic answer is that the inlet receptacle will be covered
and have a MALE plug to take the FEMALE end of your outdoor extension
cord. Remember the inlet power receptacle to your trailer should
be on the left side looking from the rear of your trailer or drivers side of the tow vehicle.
What side should power inlet be
Shore power inlet
Another shore power thread
Installing Hubbell Shore Power Inlet thread
Are shore power inlets dangerous?

To sum up the flow of power to the trailer:
The inlet power receptacle to your trailer should be on the left side looking from the rear of your trailer or drivers side of the tow vehicle. The campground power panel most of the time will be driver side of your tow vehicle when you back in. You will use an outside heavy duty 120 volt power cable with male and female ends usually 20-50 feet long (Gauge depending on your internal Gauge wire and the consideration of the cable length from the campground power panel) to hookuP shore power. Murphy's law is still in effect (That is you will have 5 foot less cable then you need to have your rig where you want it. So plan for that event). It is advised that you have an 30 AMP adaptor and a circuit tester seen above.

Again this information is rudimentary but we want you to have the flow of
how the power gets to your trailer. Now you have this information ask
away with questions that still are with you.

End 1) Power (120 volt) flow from the camp ground hookuPs to the inlet of the trailer
***.........................................................................................................................***

2) Discussion of trailer wiring inside and the use of a power panel and or using a a GFCI circuit:

These questions come uP most often here on the Electrical Secrets forum:

Question:
Can I hook up shore power and don't use a battery?
Answer:
AC power panel direct hookup to 110v? No battery

Question:
Does anyone have a basic diagram of a power layout for a trailer?
Answer:
Joanne/Kerry's basic diagram
Joanne/Kerry's basic diagram with battery charger circuit
Joanne's Wiring diagram thread
Another Wiring diagram thread

Question:
Does anyone have a basic diagram of a two way switch?
Answer:
http://tnttt.com/viewtopic.php?p=366087

Question:
Does anyone have any information on 12 Volt systems.
Answer:
12 Volt Side of Life and Battery Information � Great Information

Question:
Internal power panels, wire gauge questions & ground fault circuit (GFCI)?
Answer:
There are many setuPs here on the forum for power panels.
Read some of the forum threads and then ask questions.
BRUCE(bdosborn) GFCI and circuit breakers
provide different kinds of protection and compliment each other.
BRUCE(bdosborn) Discusses wire gauge and fuse sizes
What Gauge wire to use?
What guage wire? Battery to Fuse Panel
Wire gauge & grounding question
Wire gauge & grounding question
Fuse panel Vs. Direct Wire
AC power panel"Chuck Craven"
Fuse Blocks and other electrical items

Question:
External trailer lights are notoriously intermittent or go out, what causes this?
Answer:
Improper grounding of the white wires for lights are the usual problem.
A Guide to Maintaining Trailer Lights and Wiring.
http://www.geocities.com/Yosemite/2358/ ... s/a08.html
Search on the word "ground" in your browser to
narrow down your point of interest on the above link :
http://tnttt.com/viewtopic.php?p=186794#186794

End 2) Discussion of wiring inside and the use of a power panel and or using a a GFCI circuit:
***.....................................................................................................................................***

3) Choosing a battery and discussing chargers, inverters and converters:

Question:
What type or size 12 Volt battery should I get for my trailer.
Answer:
The short answer is a deep cell type 27 battery.
Battery Size?
Car starter vs. deep cell battery?

Question:
What are very good batteries to get if money is no problem?
Answer:
The short answer is Optima Batteries.
Link Ref.
Optima Batteries

Question:
Do you use Battery chargers?
Answer:
Chargers discussed here
Jack recommends Deltrans Power Tender Plus 5A model &
George gives more details on chargers.
Power Tender Plus 5 Amp specs
Deltran Charger Product Summary selection guide
Cabela's ProSport On-Board Marine Battery Chargers and Maintainer
12 volt Inverter / Charger Thread
BatteryMINDer� Model 12248

Question:
What are inverters and converters?
Answer:
(Administrator Jack's Definitions)
"...first, some definitions....an INVERTER, takes DCV and make it ACV....a CONVERTER, takes ACV and makes it DCV...my choice is a dual voltage system...ACV and DCV...we have wired everything for DCV with AC wiring going to a couple of outlets and a built in battery charger for when shore power is available...if I had to put only one type, it would be all DCV with inverters if needed...that way you are not dependent on camping where there is shore power available...you can also use a converter to run all 12VDC items while hooked to shore power...inverters are an inefficient choice to provide for much ACV unless you have a lot of battery power available." link Ref. Jack I vs. C

Inverter
12VDC input = 120VAC output
Conveter
120VAC input = 12VDC output
Battery Charger
120VAC input = 12VDC output

The charger and converter are the same so you can run things off the battery while the charger will float the charge on the battery. No converter needed. You will need a charger that is capable of that, a "smart charger".
link Ref. 12 volt inverter/charger

quote Jack
"I now recommend the Power Tender Plus 5A model...it is almost bulletproof and along with a good battery will do everything that most of us want at a very reasonable price...it'll also make a damn good charger when at home... "
link Ref.#2 Jack Power Tender Plus 5A model
How is a battery charger used differently from a converter?
Centurian Replacement~ It has the AC DC features like the centurian but the charger is a 3 stage charger.

Question:
What size inverter should I get?
Answer:
It depends on what appliances you will be using.
Inverter sizing thread
Inverter size for a computer and CD player / what cable size should you consider

Question:
Where do you put your battery, inverters and converters on your trailer?
Answer:
The short answer is either in the back of your trailer or in the front of the
trailer. It depends on where you want the weight of your battery to be.
Thread and pictures of positioning of units.
Tom Swenson's battery install
Other pictures of battery location

Question:
What is a way of going camping with a CPAP machine for breathing?
Answer:
CPAP stands for Continuous Positive Airway Pressure and these
machines blow a fixed amount of air pressure, specifically set for each
patient, constantly throughout the night or sleep cycle.
CPAP breathing machine camping and power options
CPAP talk on the forum

End 3) Choosing a battery and discussing chargers, inverters and converters:
***.....................................................................................................................***

4) Solar Power & Controllers:

Solar information has moved to a STICKY in the Electrical Secrets section Click here to jump to the new thread
End 4) Solar Power & Controllers:
***.....................................................................................................................***

5) Useful Tools & Charts and Information:
Battery facts ORG
BATTERIES--AND OTHER ELECTRIC STUFF
Battery state of charge thread
What is the PEUKERT EFFECT as it relates to battery discharge?
How to interconnect multiple batteries
Batteries & Chargers connected in series and parallal
Ampacity Tables N.E.C. Code Table

Simple Solar Homesteading

Led Calculator
Solar Power Calculator
Solar Power sizing Calculator

Honda Generator (Wattage) Power consumption table & formula
Power consumption table
Electricity basics 101
Deltran Battery Tender charger selection guide
Cabela's ProSport On-Board Marine Battery Chargers and Maintainer
Car and deep cycle battery answers to Frequently Asked Questions
Fundamentals and basics of charging & electricity, connecting batteries to chargers.
***

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End:

[madjack]

good work Steve...an excellent starting point for newbies and the pros alike...a truly great compilation of articles, links and threads ....thanks for the hard work and effort.........
madjack

[bledsoe3]

[b.bodemer]

Steve,
This is going to be a great winter project for me........figuring out wiring. Thanks for all your hard work. Everything I'll need to reference is right here.
Barb

[kayakrguy]

Steve,

A heckuva job. I will be using this in about...oh.....6 months <g>

Thanks for your efforts!

Jim

[Steve_Cox]

Steve,

Very Nice!:thumbsup:

[kayakrguy]

Steve and folks,

Maybe I am being picky or am wrong (again??) but there is one piece of info that concerns me in the electrical secrets thread by Steve. Here it is:

(quote) Question: Internal power panels, wire gauge questions & ground fault circuit (GFCI)?

Answer:

There are many setuPs here on the forum for power panels. Some would
have an elaborate fuse panel with meters and some would use a (GFCI)
pigtail cable that would act as a fuse panel. Read some of the forum
threads and then ask questions (end quote)

A GFCI is not a default fuse! And the reverse is true, too, a fuse is NOT a default GFCI You could overload internal trailer wiring with a power cord with a GFCI on it and possibly start a fire, or blow out a piece of $$$ equipment.

If power cord GFCI's are different in some way and I am wrong I apologize and please correct me...

Jim

[sdtripper2]

Jim:

A GFCI is not a default fuse! And the reverse is true, too, a fuse is NOT a default GFCI You could overload internal trailer wiring with a power cord with a GFCI on it and possibly start a fire, or blow out a piece of $$$ equipment.

Some would
have an elaborate fuse panel with meters and some would use a (GFCI)
pigtail cable that would act as a fuse panel.

Jim, I have changed the verbiage by taking OUT,
the part of the answer that was in contention,
and have added a thread by Bruce. See below:

So it reads now:

Question:
Internal power panels, wire gauge questions & ground fault circuit (GFCI)?
Answer:
There are many setuPs here on the forum for power panels.
Read some of the forum threads and then ask questions.
BRUCE(bdosoborn) GFCI and circuit breakers
provide different kinds of protection and compliment each other.
BRUCE(bdosoborn) Discusses wire gauge and fuse sizes
What Gauge wire to use?
Wire gauge & grounding question
Wire gauge & grounding question
Fuse panel Vs. Direct Wire
AC power panel"Chuck Craven"
Fuse Blocks and other electrical items

[kayakrguy]

Steve,

Thank you. I believe enough people DO equate GfCI's and fuses/circuit breakers that we shouldn't encourage that.

Jim

[mikeschn]

Here's an interesting reading page from a full timer on the road, who really lives on Solar!

http://www.where-rv-now.com/Notes/Amp/

Mike...

[wok]

There is a lot of good information of this page, but I just have a simple question I cant seem to find an answer for. For simplicty's sake, I know I can leave out the battery, but can I just run a big extension cord through a whole in my wall, and into a power strip like you might use for your home computer, and then use that to plug in things like fans and lights normally plugged in a wall socket at home. (This is over simplified. I would of course wire inside the walls and put it outlets and have it not look like a dump). But if I'm just using the power plug at the campsite, and plugging in things normally plugged in, need I do anything more?

[Geron]

There is a lot of good information of this page, but I just have a simple question I cant seem to find an answer for. For simplicty's sake, I know I can leave out the battery, but can I just run a big extension cord through a whole in my wall, and into a power strip like you might use for your home computer, and then use that to plug in things like fans and lights normally plugged in a wall socket at home. (This is over simplified. I would of course wire inside the walls and put it outlets and have it not look like a dump). But if I'm just using the power plug at the campsite, and plugging in things normally plugged in, need I do anything more?

Done it many a time. That's what all tent campers do. Just plug in a drop cord, plug in your "appliance" whatever. A hole in the wall works fine. They make a little "do hicky" (probably called a port) that fits in the hole in the trailer sos you can close it off and keep the bugs, rats, skeeters, flies and cool air out. Someone posted a pic of one of those ports on the forum not long ago.

[Miriam C.]

Wok They make a power strip that has a built in breaker and GFCI. They aren't very expensive and can provide you with protection you won't get with a simple power strip.

Campers are eventually in a wet environment and you need all the protection you can get.

[sdtripper2]

Wok They make a power strip that has a built in breaker
and GFCI. They aren't very expensive and can provide you with protection
you won't get with a simple power strip.

Campers are eventually in a wet environment and you need all the protection
you can get.

Aunti M (Miriam)

I think Mikes setuP best illustrates your how to have protection with a power strip.

http://tnttt.com/viewto ... 024#141024

[wok]

Awesome picture.. I think I understand... if I'm "reading" the photo right.. its campsite power in via orange cord, then run through the cylinder shaped thing with yellow that must be the protecter, and then into the power strip to split it out to the rest of the camper? My plan is to run the power in, and then of course now through the protecter (forgot the real name). Since I plan on wiring in my walls to outlets and switches, can I just use something to split the cord as it comes out of the protector and leave out the power strip? My goal is to have a permanent install for wiring. How does that sound?