Wire Size, To Converter

Dan Clayton · 06-16-2007, 08:57 PM

I am installing a new converter. Its a 55 AMP box but only will be running 30 amps to it. Does anyone know the size of wiring I should use between the shore power hookup on the trailer, and the converter? 12/2, 10/2. I have a ton of 12/2 but not sure if it's large enought. I know I have to use # 10 from the plug on the trailer to the camp ground box, but not sure if I have to use the same size to the converter. I have wired everything else 12/2 when it comes to the AC side, and have a lot of 12/2 left over.

**overlander63** · 06-16-2007, 09:30 PM

Quote:

Originally Posted by Dan Clayton

I am installing a new converter. Its a 55 AMP box but only will be running 30 amps to it. Does anyone know the size of wiring I should use between the shore power hookup on the trailer, and the converter? 12/2, 10/2. I have a ton of 12/2 but not sure if it's large enought. I know I have to use # 10 from the plug on the trailer to the camp ground box, but not sure if I have to use the same size to the converter. I have wired everything else 12/2 when it comes to the AC side, and have a lot of 12/2 left over.

12/2 should be fine, it is what was stock for our charger. Somewhere I have a chart for amps and length, you should have no problem. Also, 55 amp output at 12 volts is not what it is drawing, it should only be about 15 amps max.

thecatsandi · 06-16-2007, 10:22 PM

What size break is on the line? 15? 20? 30 amp? 15A=14Guage, 20A=12G, 30A=10G

Dan Clayton · 06-16-2007, 11:14 PM

I was going to put a 30amp main breaker in, the rest will be 15amp. I am going to wire for a air conditioner which will be a 20amp, but that spot will remain empty until I install the unit if I ever do. All the other branchs are just a couple of lights, the refer and outlets. No mirco, or any other fancy stuff, not that I would mind having some, just no place to put it. I did make room for a surround sound flat screen TV. I can only fish and play so much golf in one day, plus it will keep my kids busy when the weather gets really bad.

**overlander63** · 06-17-2007, 07:34 AM

Quote:

Originally Posted by Dan Clayton

I was going to put a 30amp main breaker in, the rest will be 15amp.

You really don't need a 30 amp main breaker, between that and the 20 amp A/C breaker you will be exceeding the rating of your power cord. Most coaches have 20 amp A/C, and 20 amp coach breakers. Also, if you put in a 30 amp breaker, chances are it will be too strong to protect your circuits, you will damage other wires and systems in your coach before it trips.

markdoane · 06-17-2007, 07:54 AM

You should put in a 30a main breaker, and run the branch circuits off the main. You can run up to five branch circuits.

LeilaM · 06-17-2007, 09:24 AM

The converter should have a label with the input current draw. As noted above, the 55 amp rating is for the 12 volt output. Depending on the efficiency of the converter, it should require a little more than one tenth that current from the AC supply. At most I would think your converter needs 7 amps peak.

Your 12/2 wire can handle 20 amps. Circuit breakers protect the wire and outlet, not the appliance. NEVER install a breaker rated for more current than the wire. If you are installing a new circiut to the converter using 12/2, then protect it with a 20 amp or lower rated breaker. In my Safari, the converter sits in a polyethylene box that is vented to the exterior. Because of the possibility for moisture to get into the box, the circuit is supplied through a Ground Fault Circuit Interrupter (GFCI) breaker. You may wish to consider the same if your installation is similar.

Dan Clayton · 06-20-2007, 09:31 PM

Thanks all for the information. I have a general idea on power, but I looked at several new coaches that had the same converter that I just bought. They all had 30amp main breaker, so I thought they had 10/2 coming from the coach shore power hookup on the outside of the trailer to the coverter, but of course you can't see the wire to be able to read it. As I stated already I have 12/2 coming out of the converter running the outlit boxs. And I had a ton of 10 gage that's running all the lights and water pump, stove fan, ect.

68 Overlander · 06-28-2007, 10:22 PM

Quote:

Originally Posted by overlander63

You really don't need a 30 amp main breaker, between that and the 20 amp A/C breaker you will be exceeding the rating of your power cord. Most coaches have 20 amp A/C, and 20 amp coach breakers. Also, if you put in a 30 amp breaker, chances are it will be too strong to protect your circuits, you will damage other wires and systems in your coach before it trips.

Terry,
I'm not sure I understand what you meant but don't want to change subject. What's wrong with 30 amp main? The other stuff would be protected by their respective breakers.