Need advice on wiring

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Need advice on wiring

Postby Kaman » Sun Sep 06, 2015 10:46 am

hello all,
I'm new to the forum and am about to start wiring my teardrop tomorrow. I've read and researched a bunch on wiring but am still unclear about the two different systems. 12v DC and 120v AC. I am not sure if they co mingle or if they stay independent of each other. If they are separate I'm trying to understand if I need to install a converter to charge the 12v or if a charger is what I would need. I understand 120v easily and don't have an issue there as long as it isn't tied in somehow with the 12 v
I searched on this thread but couldn't find any links to a wiring guide.
Does anyone know of a good link I should refer to?

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Re: Need advice on wiring

Postby KCStudly » Sun Sep 06, 2015 12:18 pm

While there are some appliances and lighting fixtures with both 12v and 120v inputs, I believe you should tailor your build for the type of camping you intend to do most.

I plan to mostly camp off grid so the only 120v I will have in my build is the shore power connector to plug in the on board battery charger (when at home), and use a portable solar panel while afield. In the event that I decide to camp where there is shore power and feel the need for 120v appliances I expect to use a multi-outlet power strip and extension cord; essentially no permanently installed on board 120v.

If you want to keep things simple (look in the electrical forum at the "simple electrical" sticky) I would keep the 120v system separate. The other option is a power center that will manage the separate systems for you, including battery charging.

In any event, I would stick with all 12v lighting and only wire 120v outlets for any appliances you might want. The individual wire runs (i.e. circuits) need to be kept separate.
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Re: Need advice on wiring

Postby dales133 » Sun Sep 06, 2015 12:49 pm

I agree with kc and ive kept mine seperate.
I realy didnt want the added complications of a power converter.
Here we have 240v and ive run a circuit breaker off my shore power inlet to 2 double power outlets in the galley and one to power a battery charger .
Ive got a small inverter if needed but my lights ect are all 12v.
Ive got probably far to many usb and cig outlets but rather do it once and future proof it.
Hope thats of some help
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Re: Need advice on wiring

Postby troubleScottie » Sun Sep 06, 2015 5:03 pm

Everything that you are saying is the way to go. Generally speaking it is hard to add in wiring after the build is complete especially when the wiring is in the walls or ceiling. So design up front as much as possible. Try to envision how you will be camping and what you have to have to be comfortable. Also if you plan to sell your TD at some point, what you think others will generally want for features. One should not assume that everyone is a die hard camper who like to only camp in the boondocks and thinks creature comforts like insulation or AC power are for wimps. Not everyone is glam camp either. Too many extra features may not increase the value of your TD at re-sale.

Here is one wiring diagram: viewtopic.php?f=30&t=63874&p=1137763&hilit=wiring+diagram#p1137763 Search "wiring diagram" and ignore the trailer wiring about 7 pin/4 pin connectors.

Generally speaking the trailers are really considered 12VDC systems. Think a hardened tent/camp site. Teardrops are not motor homes. Most people assume that the majority of the trailer devices and appliances will be powered by DC. The DC system is drawn from one or more lead/AGM/Li batteries.
DC would provide power for:
* lighting ( cabin, galley, outside of trailer )
* fan
* DC outlets
* provide AC via inverters. [ Converting DC to AC has power loses. Generally is used for low power appliances ie charging a laptop. It can used for bigger power draw items ie a hair dryer (1500 watts) for short bits of time ]

For more elaborate builds, the DC system would provide power for:
* water pump
* refrigerator (yes, Virginia, there are DC frigs )
* radio
* XM
* Television
* water heater
* cabin heater
* outdoor lighting
* techie appliances eg computers, storage devices, phones, tablets

The DC system can be charged while it is being used. So you can continue to use the DC system while the system is recharging the batteries.

Charging the batteries can be done by:
AC connection : either shore power at camp site/home or generator
DC connections: from the towing vehicle (TV) (while moving or parked) or from solar panels (while moving or parked)

Generally speaking, one is charging using only one system at a time. Most TD have at least AC charging capabilities. Some people have all of them.

The size of your battery system will depend on your power consumption, duration of outings and access to charging systems. There are computations for this on the site.

AC is added to provide:
* charging battery via battery chargers/converters
* AC outlets: 1 or more
* Air conditioning

Again, the amount and number of connections will depend on how you are expecting to camp. Generally everyone adds AC at least to charge the batteries while at home. And even the most die hard boondock camper will occasionally stop at a "real" camp ground with power. Some people cannot live without their espresso maker and blender and 60 inch sound sound satellite TV system. They is stored in the chase vehicle or the second trailer.

There are various methods for installing AC wiring from just using power strips to power distribution boxes with built in charging systems. Look through the site, search on power strip or distribution box.

The two systems do not have any shared wiring except at the point where the battery chargers are connected to the battery. Similarly, generally the running lights, signals, brake lights, etc does not have any shared wiring with the DC and AC system.

Check this site for actual wiring diagrams. The most important thing is to have proper grounding and fuses for the various circuits.
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