Shore Power Question

[beetle_slayer]

Hello, I'm new to the forum and have a question regarding shore power.  I am designing and planning out my teardrop and have a good grasp of technical knowledge (I'm a mechanic). 

When designing my trailer, should I design for 50A or 30A?  I know I don't need 50A, but want to connect what is most readliy available at camp sites.  I plan on using 12V also. 

Also, what length of shore line should I allow for?

To be clear, my questions are more about the campsite and not the trailer (ie, I know the difference in 220 and 110 power and the amperage differences)

Happy Holidays!

 

[Carl L]

Design for 30 amps.  If you need to adapt to a 50amp circuit, you use a adapter.  Since 30amp circuits are far more common in campgrounds, 30 amp is the way to go.

Allow for about 10 feet of shore cord.  30 amp extension cords are also available.

 

[beetle_slayer]

Cool, perfectly answered.  Just one more thing, assuming it is backed in, ideally where should the plug go? 

You can tell I've never been eh?

 

[Lou Schneider]

Utilities (water, electric, sewer) are almost always on the left or street side.

You should have a 30 amp inlet, along with an adapter for the end of your power cord to adapt down to a standard 15/20 amp outlet.  50 amp to 30 amp adapters are also available, to let you plug into a 50 amp socket, but I doubt you'd ever need one.

Are you installing air conditioning in that teardrop?  If not, you really don't need 30 amp service.  A 20 amp inlet that mates to a standard 25 ft. 12 gauge orange extension cord would be sufficient and a lot easier to store and handle than the equivalent length 30 amp cord.  And you can get 30 to 20 amp cheater adapters to let you plug into a 30 amp outlet in that rare case where you find a campsite without a conventional 20 amp socket.

 

[John From Detroit]

For a teardrop I'd go 30 as well.. let me give you a set of "rules" I call these the rules according to Oliver Wendell Douglas (TV Show: Green Acres)

"Big Ticket" items are those that pull 1KW or more, Water heater, Air conditioners, Microwave, Space heater, Hair dryer.

Medium is around 500 watts (RV type fridge)

TV, Radio, and support electronics,, Small ticket (Do not count)

Your converter (The think that makes 12v out of 120v and charges your battery) is a variable, if house batteries are very low, and the converter is big enough (mine are) big ticket. else small

20 amps.. 1 Big ticket, no medium, watch the smalls too

30 amps 2 big ticket, plus the small ticket items and the fridge (NOTE: if you trip breakers kill the fridge)

50 amp,  All you can eat

I'd be amazed if a teardrop had two Air conditioenrs, and if you kill the electric water heater before microwaving lunch.. You should be good.

They make automatic Energy Management Systems... That will do that for you.

 

[beetle_slayer]

At first, I will have only lighting and elec water pump (probably 12v though).  I want the option to expand to fridge and possibly A/C cuz its hot in TX!  A few flourescents and a radio are minimal load.  12V with a solar charger would be ideal, but its not realistic.  I would be better off with 30A for possible future upgrades as its easier now than later.

Another thought is that I will be running gas cook stove and no water heater.  Also, the a/c shouldn't need to run a lot due to small space and only in sleeping hours.  30A should be sufficient.

Jon

 

[Wizard46]

Just keep in mind that there is a lot of " see it - want it" when looking in catalogs and stores. Always plan for more in the beginning.

 

[beetle_slayer]

A thought, if I make it 50A, is it ok to make a passthrough circuit to my brother's teardrop for sharing a site?  This is assuming the site has 50A service.

 

[Alfa38User]

Bear in mind that 50 amp service for a trailer or motor home is actually 100 amps, 50 amps on each leg. 30 amp service is actually only 30 amps on 1 leg.

That said, I am not sure what you wish to do or what you mean by a pass through in this context, nor do I understand what is meant by sharing a campsite as this practice may not be acceptable to the campground owners.

 

[John From Detroit]

As for a pass through circuit.. I have two of 'em on my coach..  They have been used.. A few times.. I will list:

campground, power failure, I passed power to a trailer one site over

Quartsite, Generator failure I passed power to a fellow forum member.  (That was actually kind of fun)  by the way I hope to make it again in 2014, will know more mid year.

The reason I put in the circuit was not the TT-30's but the twist lock that is there as well.  It's to power the house when lights fail. which they did about once a year before I went full time.

I also have the 30 amp cord from my old Trailer (This was an added cord, it also had a 20 amp power system) This is basically a 30 amp cord with an Octo-outlet on the far end. (8 outlets) I use it from time to time when I need power where it's at instead of where the patio outlet is.

 

[bucks2]

Hmmmm.... a lot of good ideas. Here's mine. Make it a 30 amp for all the reasons stated above. Make it a quality cord with a soft supple cover. I forget the four letter designation but buy quality and you'll thank yourself every time you wind up the cord. Design a reel system to store it. Even if it's just a reel that you reach into a compartment and manually turn the wheel with a spinner knob. This will probably fit in an out of the way spot, will provide neat storage, and if designed to hold 30' of cord will take care of 98% or more of your parking spaces. I have 45' of cord on my 43' MH which isn't quite as easy to park near the power box at all sites and I use my extension cord fewer times than I have fingers on one hand each year. (in 7 months of full timing each winter) A teardrop isn't going to have a lot of unused space so put your cord on the reel and don't bother carrying an extension.

In my experience virtually no park (RV, state, fed) allows two rigs in one spot. So a pass thru is probably not cost effective. A 20 amp weatherproof outlet on each side of the rig will be much more useful. For everything from vacuuming the car to running the air compressor and pumping up the tires. Outside outlets could also be used in a pinch as a supply for the next camper over if needed.

Ken

 

[Gary RV_Wizard]

Just put in a 20A outside outlet, as bucks2 suggested. That will "pass through" power to whatever you choose to plug in.

You probably don't ever need a "pass-through" for another camper. Most campsites that will allow two rigs per site will have at least two power outlets. Even those that designated for a single RV typically have both 30 and 20A outlets on the power pole.

 

[beetle_slayer]

Thanks for the input guys.  I was not aware that sharing was not allowed.  I am definately planning a couple of outside plugs, so that could be a viable option of passing along power if needed.  I know the SO cable ( I think its SO) is very nice and also expensive.  I just made a 30 foot shore cable to replace the one that got stolen for our race trailer.  The ends alone were $120 each and the 4/4 cable....over $200 for 30 feet.  It is a semi trailer car hauler with onboard welders, a/c, liftgate, etc.  So yeah, you get what you pay for! 
I'll probably go with 30A just for the simplicity and I don't see ever needing more than that for a teardrop.
Jon

 

[bucks2]

Just as a thought, sometimes marine shorepower cables go on sale. Often they are reasonably supple and easy to handle. On the power post end you'd have to put either an adapter or replace the end, but on the trailer end you could use the standard marine 3 prong twist lock.

Ken