> Subject: Re: [A/S] 12v outlets
>
> Are you talking about the cabinet design, Rick? It's a simple wooden cabinet console with shelf storage under a flat surface area. There are center upright supports and side walls that can hold outlets. This is for a space that replaces the front gaucho on a '99 Safari 27' and the inverter is at the front center underneath the fuse box which is on the wall at the rear of what is now a cabinet. I can take a picture of what's built so far and post it. The carpenter's brother is a licensed electrician but I don't know how much 12v experience he's had.
>
> What I am curious about is that these freezers are marketed for extended use on boats and RV's and come in several different brands. I'm hearing you say they are all too beefy for the existing connectors and wiring? Nobody plugs in a freezer for just a few minutes!
There are two open 20amp circuits on the coach circuit breaker.
>
> Also, the freezer power cord/ plug is very secure---believe me I tested it this fall! However I pulled it out by stepping on the cable more than once, which is why it will be much safer in it's own little ventilated space under the shelves.
>
> What would you recommend? If I start cutting off plugs and wiring on new ones, I'll void the warranty and maybe cause other problems. I can't imagine they sell so many of these and don't put on substantial connectors. But I'm open to horror stories if you have them. I'll go try to take a few pictures and upload them if I can get my camera phone to work.
>
> Anne in VA
> On Mar 9, 2012, at 4:06 PM, Anne Pearse Hocker wrote:
>
>> Someone was mentioning 15 to 20 amps, and while you can get away with
>> current like this for short periods of time using a lighter jack, the
>> resistance in the design causes the jack/plug combination to heat up.
>> This causes a failure eventually. And wiring is generally not sized for
>> pure lighter use to be large enough to keep the voltage drop and wiring
>> heating where it should be. When you are designing for a 10 second usage
>> of power to hear a lighter, you can cut a lot of corners.
>>
>> Even at 6 amps I would recommend using some other connector than a
>> lighter jack and plug. You want something that is low loss and will stay
>> connected so that you don't have food spoilage because the plug fell out
>> or the spring in the lighter plug or jack weakened because it got hot.
>>
>> As to wire size, this is dependent on the length of the wire. And that
>> is the length of the wire times 2 because you have the positive and
>> negative wire losses due to resistance to factor in. Resistance is a
>> much larger factor at 12 volts as a percentage of loss because of the
>> lower voltage. So you will want to make sure that the wire resistance is
>> low enough (i.e. wire gage sized right) to keep this voltage loss as low
>> as it needs to be. This will be easier on any device plugged in as the
>> voltage won't sag as it draws more current. This cycle causes it to have
>> to draw even more current to keep operating, and in anything with a
>> motor, this causes more heat in the motor.
>>
>> Wire should be stranded, and a fairly fine very flexible stranding, with
>> a good protective and flexible high temperature jacket (insulation)
>> material, to prevent stress breakage from vibration as the coach moves
>> down the road. And appropriate crimp-on lugs should be used, never
>> soldered connections (these cause solid flex points and will fracture
>> eventually.) All transitions as the wire passes through any bulkheads
>> should be grommeted to prevent wire movement and chafing.
>>
>> If we know more about the design, we can offer real concrete advice.
>>
>> Rick Kunath
>> WBCCI #3060
>>
>>
>>
>
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