I am getting ready to start doing some ac electrical wiring in my conversion and want to know what everone uses for their ac wiring. I like the idea of mc/lite bx because it is protected with the aluminum outer shield and is lighter than the steel bx.
O BOY is this gonna be fun ::)
What ever you do will be WRONG or what ever you do will be RIGHT
I like conduit and thwn stranded but lets see what others say
HTH
Melbo
your prob one up on most of us with your work back ground. I'm using plastic conduit for main duct runs in 98. some behind cabinets and 2 overhead to front. Also using stranded wire > individual color coded as to use and to circuit ;also voltage 12v/120. Mostly be concerned with wire size/load and sharp edges. one undersized wire can burn up /short out a hole bundle of wires or worse-I try to over size load by one size-.rite or wrong. Boxes ;we are in a big metal ground so anything we attach to bus frame work is going to earth ground when plugged into shore power. Cabinets are a differant case .So your choice of boxes is personal decision
Many have used romex, but that is really not the right stuff to use. They use multi strand in motor vehicles/aircraft, because they vibrate and wiggle stuff around. Solid core wire is too brittle and can easily break which could create a short. Stranded is much more flexible and if well secured will last many decades. That said, I dont think I ever saw conduit in a motor vehicle. Wire instead is ran in wrapped bundles and well secured to walls and bulkheads so it will not move.
Its always better to oversize wire than undersize for the expected load. That way it runs cooler. 10 over 12 or 14, 8 over 10, 6 over 4, etc.. within reason
Some have used extension cords, but the consensus seems to be to use better grade wire. Some argue the insulation isnt the right stuff.
However you do it, try to do it as close to building and electrical code and with as good of workmanship and materials as possible. These rigs become very complex with many different systems and appliances and can easily become a fire hazard.
If you do a search, you will come up with many different threads asking the same question.
Like this one for instance.
http://www.busconversions.com/bbs/index.php?topic=20127.0 (http://www.busconversions.com/bbs/index.php?topic=20127.0)
Lots of good stuff in the archives to glean over.
Have fun and keep the smoke in, OK! ;)
I used Romex because all of my RV's and trailers going back 20 plus years had Romex and I never once had a wire break due to vibration. That said, I do give some credence to that argument, I just didn't think there was enough to it given my personal experience. The other reason I used Romex is that all of the breakers, switches, connectors and terminals that I was going to use on the 120 VAC side are made for use with solid wire so I felt the easiest and most satisfactory thing to do was to stick with that they were designed for. Again, I know that you can use terminal rings on stranded wire and use those switches and such, but I'm not that familiar with typical 120 VAC breakers that are designed for stranded wire, although I'm sure they are out there.
Anyway, I used Romex, my truck camper that I still have uses Romex, and the car trailer that I just bought a couple of months ago uses Romex for the air conditioner pre-wire. I think Romex is a fine choice but I'm not saying it's the best choice just because commercial builders of S&S RV's use it. Just that it's a valid choice.
Brian
Motor vehicles don't use conduit because the wires are low voltage. 110 volt requires conduit if using individual wires. If using a cable you don't conduit, but then it has to be protected against damage.
I like the idea of bx but this thing about grounding is a concern. Does this mean that the AC ground or the bx metallic shield must not touch the bus structure in any way so that the bus does not become an AC ground for any reason. I know at the panel neutral and ground must be isolated.
If your bus is not earth grounded and you are on wet ground (rainy day and you touch it) do you risk a shock?Food for thought
I have used Romex and stranded wiring can't see much difference in either S&S sometimes have a problem with the Romex but it is not the wire problem it is the cheap outlet's,wing nuts and the switches
I was told by a converter (Prevost) never to use the plug in feature on the electrical outlets and switches in a mobile unit always use the screw terminals and the Romex will never break there I wouldn't be afraid of Romex you tear in to one of the high end conversions it will surprise you what's in there lol
good luck
The bus chassis should be bonded to the electrical ground in the main panel and to the ground of the source of electricity. If that is the pedestal, it will itself have a path to ground as in the actual ground that you walk on. If that is a generator, you have the option of (my generator recommends this) of grounding the generator itself with a stake.
I was plugged into my garage outlet with a high resistance ground at the outlet, and measured 50 volts from the chassis to the ground beside the bus. I'm a big believer in grounds.
Brian
Electrical Code(NEC) - I believe - specifies "romex" or conduit. I used boat. Available is different color insulation.
For convention the bus companies use white for DC ground. I went with brown for DC ground,negative, red for positive. Heating system control, fan power etc is yellow.
Bill
Quote from: scanzel on August 10, 2011, 06:05:42 AM
I know at the panel neutral and ground must be isolated.
This one has me stumped. Today at the electrical supply place I asked the man specifically about this. He said he never heard of "neutral" and "ground" being two separate circuits. And he does huge factory installations.
So what does Neutral connect to and what does Ground connect to?
Retarded minds want to know!
An extra benefit of conduits, should the necessity to replace a wire arise, is A LOT easier to just pull the offending piece from it than ripping open the interior.
Will try simple explanation. Green wire does not attach to same ground lug in box or on supply at camp ground supply as you white system ground. The green wire is a earth ground in case something inside your coach would put a electrical charge in your coach it would not go to you but would go to the green wire earth ground instead. Imagine standing on wet ground without one and touching your coach and a obscure wire joint or appliance has failed and you become the ground instead of the green wire. Also if your white ground wire would fail it will help keep you safe also. The two should be seperate circuits and never connected. That would cancel their purpose. If you want a technical explanation search Earth Bonding & Grounding. Bob Ps look at bevans 6 post again
I used metal conduit and stranded.
Bob things are a little different in Mexico what you are saying is correct but Mexico unless the have changed uses no grounding plugs like we have here only the 2 prongs most places there you really have to watch 30 and 50 amps plugs no telling what you will get lol most of the time it will be 220v
good luck
Steve. When you travel in Us there will be A green Earth Ground. A old trick before this was adapted here in the 1960's when we approached a metal bldg or bus we touched it first with the back of our fingers during wet weather. If it had a electrical charge your hand will contract and push away. If you grip it with your palm it will contract and you can't let go. Be safe and live long. Bob Only did hand thing if had doubts had a couple times I didn't that I wish I had.
Quote from: Mex-Busnut on August 11, 2011, 07:22:13 PM
[He said he never heard of "neutral" and "ground" being two separate circuits. And he does huge factory installations.
So what does Neutral connect to and what does Ground connect to?
The two main plugs in a standard houshold electrical outlet signify the hot and neutral. You have to have both to run anything. In the US the voltage between those two is 120 volts, what Mexico has I dont know. In the US we have outlets with three terminals. The two slots plus a round terminal below them. The round one is a ground wire. If your power saw shorts out, rather than electrocute you the energy will go into the ground wire.
As an example, in my yard I have power strung up here on power poles. The last pole has a meter and main power disconnect. All power comes from that panel into the house panel. Power at the pole is 7240 volts IIRC. There are two wires, one hot, one neutral. The neutral is connected to a copper wire stapled into the pole that is connected to an 8 foot copper ground rod driven into the ground. The hot and neutral both goes into the transformer that drops the voltage to 120 volts on two wires called legs, and three wire come out, two 120 volt hots, and the neutral. They come into the disconnect, the two hots connect to the two side of the main breaker. The neutral goes to a "bus" bar. The ground comes into the box and goes to a seperate Bus. I have four wires going into the house panel. Two connect to the main breaker at the pole, one connects to the neutral Bus, the other connects to the ground Bus. In the house panel, all neutrals go to the neautral Bus, and all grounds go to the neutral Bus. Therefore, all grounds at the outlets in the house are grounded back to the pole. All neutrals are isolated from ground "except" at the pole. Often there are additionalground rods at each breaker/fuse panel, and also ground wires connected to water lines.
In an Bus with a generator, you have the same deal, but the Bus isnt grounded to earth, its isolated from the ground. All grounds go to the chassis ground, all neutrals go back to the generator along with the hot (s). The ground and neutral are connected together "bonded) at the generator, just like at your main disconnect in your house.
There is a problem connecting the Bus generator to your house system, because of the bonded neutral at the generator. With your Bus NOT grounded to earth, you could get killed if you touch the Bus under the right conditions. Its rare, but it can and has happened.