idaho211
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Post by idaho211 on Apr 30, 2017 17:35:55 GMT -8
First off great web site!! I bought a 66 Kenskill and am getting ready to wire the 7 way towing in and coming up with a list of stuff I am thinking about wiring with a j box like Vikxx. Question, I had was what size of battery wires coming to the j box and what size of breaker switch for the hot wire? Since I have a metal tub floor ( unfortunately) thought about putting a wooden backer plate then screwing the j box on it. Appreciate your help.
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Post by vikx on Apr 30, 2017 20:30:12 GMT -8
Wire gauge from the battery should be 10 to 8 gauge. (that depends on how big of a system you have) Kenskills tend to be higher end and may have a more elaborate 12 volt system. If you go with simple and 2/3 of circuits, 10 gauge wire would be plenty big enough.
The size of the breaker is determined by the size of the system. Most vintage trailers use a 20 amp self resetting circuit breaker. Modern RVs have a 30 amp (or larger). Also, wire gauge determines the breaker size. Using 10 gauge battery wires will support a 30 amp breaker but I usually go with the 20.
The breaker size determines the size of the hot wire going into the trailer. 20 amp breaker needs a minimum of 12ga. 30 amp breaker will need 10 gauge.
The above is for "most" vintage trailers. They have smaller and simple 12 volt systems. If you are planning on an inverter or more than one battery, then everything must be designed around that. (larger gauge battery wires, at least a 30 amp breaker, etc)
Hope this helps.
Last thing: do a lot of inspecting before finalizing your J box install. If there's rot, you'll be removing it and re-installing...
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idaho211
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Post by idaho211 on Apr 30, 2017 21:36:09 GMT -8
Thank you for the reply. I need to figure out how to send pictures but it has what looks like a factory 30 amp breaker with two 20's. There is a factory diagram showing the 30 and the 20's, it also has a factory convertor. The convertor is called DCV and is used for d/c power supply and battery charger. I have the manual along with other manuals with the trailer.
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Post by vikx on Apr 30, 2017 22:57:08 GMT -8
Ah. So you are talking about 3 different systems: Tow wiring (7 way), trailer wiring (12 volt system inside) and 110/120 volt AC system...
So, for the 7 way, use the info above.
The 110 system has a 30 amp inlet leading to the breaker box. This box runs the 110 lighting and outlets in the trailer. More info is needed to decipher what you need to do.
Many older trailers did not come with a 12 volt system. It seems yours did, with a converter. It would be good to consider a more modern converter with a "smart" charger that will maintain the battery(s) without damage.
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idaho211
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Post by idaho211 on May 1, 2017 5:57:16 GMT -8
So I will put in a 30 amp breaker switch in my j box and run 10 gauge wire for hot battery. I looked up the manual about the the old convertor and it says it has a "sensor" that makes a 100% shut off and stays off until the battery charge level drops below the shut off voltage so I am wondering if I need to get a new convertor because it sounds like it is a smart charger as well.
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Post by vikx on May 1, 2017 20:42:38 GMT -8
I've not heard of a "DCV" converter. Is that the brand? You could certainly try the old converter and see how the batteries do. If it truly does shut down when the battery(s) is at full voltage, my guess would be that it won't overcharge.
Still, testing is the best way to determine how well the converter works.
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idaho211
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Post by idaho211 on May 1, 2017 21:09:43 GMT -8
Yes DCV is the brand. I will send some pics when I can Thank you for your advice.
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cowcharge
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Post by cowcharge on May 7, 2017 7:14:39 GMT -8
Get a $5 hydrometer at an auto parts store, that way you can get a true reading of the charge to make sure everything is working correctly. A voltage test is iffy at best, and can be waaaay off. Also, nowadays battery makers are specifying much higher voltages for charging, like 14.8v. So if your converter is working properly, slow charging will be the most likely issue.
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idaho211
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Post by idaho211 on May 7, 2017 19:08:01 GMT -8
Thanks I will look into it. Regarding wiring I am putting in a metal j box underneath floor for 7 way to trailer wiring. Trailer has metal tub floor. Stupid question should I put an insulated backer between the metal floor and j box like a piece of wood screwed into the floor joist? Thanks
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Post by vikx on May 7, 2017 22:29:59 GMT -8
You don't need to insulate the box but a backer is a very good idea to support the box. Most trailers have wood runners, so you could screw a piece of plywood across and then attach your box. The box has a ground screw thread and I often use that for extra grounds inside the box. Of course the main GROUND comes from the frame.
Also support the 7 way cord with a rubber/metal clamp outside the box. Insurance.
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idaho211
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Post by idaho211 on May 8, 2017 6:37:39 GMT -8
Very helpful to know. Thank you.
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idaho211
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Post by idaho211 on May 9, 2017 7:08:33 GMT -8
So getting ready to wire 7 way in and decided to check size of ground and power wires from trailer side of harness and found they are 12 ga solid wire and the black and white are sleeved together separate from the other wires. Convertor instructions recommended 8 ga wire coming from the battery to convertor. Should I leave it 12 ga? I assume there was a reason for 12 ga and not larger?
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Post by vikx on May 11, 2017 20:26:34 GMT -8
First of all, trailers should use stranded automotive primary wire rather than solid. It has to do with the motion going down the road, flexible is better.
If the converter calls for 8 gauge, I would change the battery wires. Sounds like a PO decided 12 was OK.
Also, be sure the wires are what you think they are. Sometimes, the sheathed wires run to the brakes rather than the battery. (also stranded, not solid).
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idaho211
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Post by idaho211 on May 11, 2017 21:53:06 GMT -8
Thank you. I will check it out and let you know.
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idaho211
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Post by idaho211 on Aug 1, 2017 14:10:30 GMT -8
Back to wiring. Looking at the breaker switch to buy there are different kinds modified reset, auto reset and manual reset. Which one to get? Leaning towards modified reset. What I understand it will trip if power surge and stay off until power is off then reset. I am using it in my breaker box for 7 wire conversion like vikx does. What do you think?
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