Power cord access while TM is closed

**Bill** · 10-23-2002, 10:37 AM

Back on August 12, Wade started an interesting thread titled 2720 Wish List for his then-new TM. The third item on his wish list - a wish shared by many - was to engineer access to the power cable for battery charging and refridge operation while closed. The group kicked around a number of thoughts, looking for a method that was both convenient and SAFE. Consensus was that a small auxiliary cord would be OK - no need to use the big 30 amp cable, which isn't normally accessible when the TM is closed. In this discussion, I was the safety guy - I couldn't figure out a way to have two power cords without creating an electrical hazard. (I am an EE and sometimes electrician.) The thread eventually petered out for lack of a solution.

I have thought about the question off and on since then, and the solution - a convenient and SAFE solution - finally popped into my head. And it is easy, and parts cost only about $10-15.

The desire is to put the plug end of a small AC power cord in some spot that is accessible when the TM is closed. My choice would be the back bumper compartment. If this cord is plugged into a source of AC power, then it will provide AC power to the refer and to the battery charger, and nowhere else. If the cord is unplugged, then the refer and charger AUTOMATICALLY revert to the big 30amp power cord. The word AUTOMATIC is important - with AC power projects, nothing should depend on the memory of a weary traveller. And furthermore, if BOTH the big cord and the little cord are plugged in, there must be no hazard.

The solution? In my 2720, anyway, one of the 20 amp circuit breakers in the AC power distribution panel feeds both the refer and the power converter. At the output of this breaker, we insert a changeover relay. The relay is wired up so that this circuit is normally fed from the big 30amp cord, but if the small cord is plugged in, the relay activates and feeds this circuit (and this circuit only) from the small cord. Voila - the function is accomplished.

If anyone is interested in doing this, I will provide a diagram and source for the relay by email. (The board's server doesn't seem to be accepting graphics during the site change.) WARNING: I do not encourage you to undertake any AC power project yourself if you are not throughly comfortable with AC power wiring, house wiring, etc. The job is not hard, but as you know, the consequences of doing it wrong can be severe.

Bill

10-23-2002, 11:14 AM

Upon leaving from our vacation this year, I forgot to undo the power cord when I closed the TM. LOL, it closed just fine! I didn't have it all clamped down or anything, but there it sat with the big 30amp plug still plugged into the ac power! Didn't seem to hurt anything, it's set up again in my driveway plugged in, the cord's fine, the TM's fine, and everything works. Just a thought...........

[glow=red,2,300]Happytrails..........[/glow]

10-23-2002, 01:13 PM

Bill, I would appreciate looking at your plan for providing 110 volts to the trailer with the top down.

Thanks,

Hal
[email protected]

**Bill** · 10-23-2002, 01:14 PM

Different fit / different clearances, I guess. I've tried (by mistake) to close mine a couple times with the cord still out. It just won't go!

Bill

10-25-2002, 01:04 PM

Is there any hazard if the exposed, unplugged power plug gets wet? (Like from heavy rains while traveling)

10-26-2002, 09:45 AM

Bill,

I somehow missed this thread until today. I am very interested in your diagrams and believe I could do the project myself. I'm not sure where I would place the outlet yet, but probably not in the bumper. I thought about adding a second covered AC outlet box next to the external factory box for this, but I've not yet decided.

Wade

**Bill** · 10-27-2002, 01:48 PM

Quote:

Is there any hazard if the exposed, unplugged power plug gets wet? (Like from heavy rains while traveling)

No danger whatsoever. This is one of the things I worried about when we all originally considered a solution. For myself, I will place the power plug itself in a plastic box in the bumper compartment to keep it dry - but only to prevent corrosion/rust/etc. If it gets wet, there is no electrical problem or danger, because it is not connected to anything except the changeover relay. The changeover relay, where the action takes place, is mounted in the lower half of the converter box, inside the TM, safe from any rain/snow/road salt, etc.

Bill

**Bill** · 10-27-2002, 02:03 PM

Quote:

Bill,

I am very interested in your diagrams and believe I could do the project myself. I'm not sure where I would place the outlet yet, but probably not in the bumper. I thought about adding a second covered AC outlet box next to the external factory box for this, but I've not yet decided.

Wade

Wade -

I have sent you diagrams by private email, since the board's server doesn't accept graphics yet. Be aware - this isn't an outlet, meaning a socket. This is a plug, like the male (plug) end of an extension cord. You can have this plug hang anywhere that is accessible when the TM is closed, but it ought to be protected from road grime/sand/salt/etc so it won't corrode. It sounds kind of rinky-dink, but I am installing a 6 x 6 x 2 inch Tupperware box with a screw-on lid in the rear bumper compartment of my 2720. The cord passes through the wall of the container, sealed with silicone caulk, and the plug (on a 12 inch length of cord) is inside the container. When I need it, I open the bumper compartment, take the lid off the Tupperware, pull out the plug, plug an extension cord into it and the other end into the house, and voila, the TM refer and battery charger are powered up.

If you do this - especially if you choose a different location for the free end of the cord - let us know how it works out for you.

Bill

10-28-2002, 12:49 AM

Bill,

This sounds very workable and not "rinky-dink" at all. The idea of a Tupperware container for water proofing sounds good. I was aware that the outlet would be the male end and figured I could somehow mount one deep enough into an outlet box. I'll have to poke around for a good spot when we get the TM next week. Thanks for the plans - they are excellent!

Wade

10-28-2002, 09:28 AM

I would really like to see those plans as well Bill if you could send em to me, I'd really appreciate it! [email protected]

[glow=red,2,300]Happytrails........[/glow]