Wiring 50A coach plug

[opus]

My advice would be that if you have to ask that question, hire an electrician to wire it.  I kinda knew what I was doing but that is something I didnt want to leave to chance and inexperience....POOF!

[gumpy]

Craig- A little hijack here-- I would be interested in your creative solution to the inverter issue since I have been known to forget to turn the water heater off before switching to the inverter.  I have considered using a sub-panel, but have been managing with putting reminder markers on the switches.  Sorry

Yeah, it doesn't solve that problem. That's called operator error. 

I have an electric element in my AquaHot that I constantly forget to turn off. The house A/C is another one I forget to turn off. My inverter is 4000 watts,
and has auto-gen-start, but sometimes that just confuses the issue. My transfer switch is built with 4 DPDT relays. It provides neutral-ground bonding, switching of the inputs, and crossover of
the two hot wires when on 120V shore (separate when on 240V shore). I removed the schematic from my website because I got some flack for it not being "to code", but it works very well
for my needs.

[Emcemv]

I'm with opus on this one, Dave, as a minimum, get some advice from an electrician on this. I saw you mention knife switches, open knife switches are very dangerous and are hard to cover to make them safe.  Instead of knife switches, use contactors or relays. 

[Lin]

I am strictly an amateur at electrical but have completely rewired several houses aside from the work on the buses.  The way I learned was to pay a very kind and reasonable electrician as a consultant on the first house I did.  It is not terribly complex; you will pick it up easily.  He would point out what to do and I would call him when done for him to inspect.  As suggested by others, you could save yourself a lot of headaches, time, and consequences by doing something similar.

[Tikvah]

I appreciate all the comments and helpful insight.  I chuckle a bit about my use of terminology.  When I say knife switch, I just mean a shut-off... or whatever the current term is.  I'm a bit dull, but not to the degree yet that I would use an actual knife-switch (although it would work).

I'm a little shocked (pun intended) about all the advice to hire a professional.  Really?  I can build an entire bus based on some gray matter between my ears and with the help of good folks like you.  But, when it comes to running four wires from a socket to my panel I need a professional?  What about my plumbing?  Or, worse, my batteries?  You can burn a bus to the ground really fast be screwing up the battery system.  Oh, and my brakes!  Okay, end my rant there.

I'll try to make this simple... Everything I have is 110V.  No stove, oven, or large AC system.  I have a panel with breakers.  There is a left side and a right side to the panel (ya, it zig zags, but lets not confuse the facts).  Obviously the panel is intended for 220V systems (two 110V leads).  But, since I don't need the two separate leads that make 220V, I have jumpered the top of the two rows of breakers. (ran a heavy wire from one side to the other, like two inches).  Now, I have two rows of 110V all on one 110V supply wire.

This make sense so far?

So, if I was to hook up a 110V 20Amp or 110V 30Amp, or 110V 50Amp it wouldn't matter, my entire panel would be hot with 110V.  BUT, if I hook up 50Amp 220V (two 110V leads) now I have a problem.  My little magic jumper wire is going to blow the lid off the campground... and maybe my bus.  So, I got this wild idea that if I pull that little magic jumper wire out and put a switch inline, then make sure that switch is off (open) when I have 220V supplied to the box that I will magically have 110V on both sides of the box, with 50Amp supply on both.  But, when I only have 110V supply, I can turn the switch on (close) and have 110V on both sides, but only the amperage available from the one line.

With me so far?

Ok, be kind.  I realize that if my brain didn't engage and the switch was on (closed) when supplying 220V that we would have issues.  Yes, it can be done with a relay, but the result is the same, if the switch is closed - poof!  There must be a fool-proof solution.  Also, someone mentioned that the readily available RV adapters combine the lines.. is that true?  If that's true, I can let the adapter take the place of my magic jumper wire and the single 110V supply will automatically go to both sides of my panel.... until I hook up my generator.

Grab your sling shot... time to throw some stones in my theory.

[oldmansax]

I'll try to make this simple... Everything I have is 110V.  No stove, oven, or large AC system.  I have a panel with breakers.  There is a left side and a right side to the panel (ya, it zig zags, but lets not confuse the facts).  Obviously the panel is intended for 220V systems (two 110V leads).  But, since I don't need the two separate leads that make 220V, I have jumpered the top of the two rows of breakers. (ran a heavy wire from one side to the other, like two inches).  Now, I have two rows of 110V all on one 110V supply wire.

This make sense so far?

So, if I was to hook up a 110V 20Amp or 110V 30Amp, or 110V 50Amp it wouldn't matter, my entire panel would be hot with 110V.  BUT, if I hook up 50Amp 220V (two 110V leads) now I have a problem.  My little magic jumper wire is going to blow the lid off the campground... and maybe my bus.  So, I got this wild idea that if I pull that little magic jumper wire out and put a switch inline, then make sure that switch is off (open) when I have 220V supplied to the box that I will magically have 110V on both sides of the box, with 50Amp supply on both.  But, when I only have 110V supply, I can turn the switch on (close) and have 110V on both sides, but only the amperage available from the one line.

With me so far?

Ok, be kind.  I realize that if my brain didn't engage and the switch was on (closed) when supplying 220V that we would have issues.  Yes, it can be done with a relay, but the result is the same, if the switch is closed - poof!  There must be a fool-proof solution.  Also, someone mentioned that the readily available RV adapters combine the lines.. is that true?  If that's true, I can let the adapter take the place of my magic jumper wire and the single 110V supply will automatically go to both sides of my panel.... until I hook up my generator.

Grab your sling shot... time to throw some stones in my theory.

Yes that will work. But, again, one mistake forgetting to flip that switch & you will have major problems. That would be too much risk for me, knowing I might forget it once in the next 10 or 15 years. However, you may be way younger than me & your brain still works....   

I used a standard Square D panel because you can get them and breakers anywhere at a reasonable price. You can buy straight 120V panels but they are specialty items & you will pay extra for the "marine" or "RV" names.

If you really want to do the jumper thing, just wire the bus for 30A only. Then you can't get into 220V by mistake unless you plug into somebodies welder receptacle in a shop;however, that's a whole 'nother discussion. Still, if you end up with a generator that puts out 220V, you will have to rewire. Also, lots of 110V RV generators have two 110V legs that do not make 220V across them but STILL cannot be wired together. With either generator, you would only be able to use 1/2 the capacity and generators like to have balanced loads.

Yes, the adapters are real and lots of Walmarts have them.

TOM

[gumpy]

Ok, follow this...

On my coach, as I mentioned, I had an issue with my inverter and the 30 amp dogleg adapter because it had the two hot wires combined.

On your coach, I think that may actually be the solution you are looking for. Follow along...

Wire your coach with a 50 amp inlet. Two hot wires going to either side of the breaker panel.  You have a 6/4 cable with a 50 amp plug on it for
hooking into a 50 amp, 240v outlet. Both sides of the panel are powered with 50 amps of 120v. You don't care about phase because you don't have
240v appliances.

If you don't have 240v available, you attach a 30 amp dog leg adapter. There's a male 30 amp plug on one end and a female 50 amp on the other.
Inside this animal, the single hot input wire is split and attaches to both hot wires on the 50 amp end. Bingo. Now you have both sides of the breaker
panel powered by 120v. Of course you have to limit your power consumption because you only have 30 amps available. No knife switch, rotary switch,
contactor, relay, etc. Only one 6/4 power cable, and a dog leg adapter.

Now, you get to a friend's place who only has 15 amps available. No problem. There's another adapter with 15 amp male on one end and 30 amp female
on the other. Plug that puppy onto the dogleg (get it?), hook the dogleg to the 6/4 cable, and you're good to go. You have 15 amps being split and
powering both sides of you breaker panel. Again, you have to manually limit your consumption.

Easy peesy, lemon squeezy.  

Ok, what was your original question?

craig


By the way, hooking up to your generator is no different, if you have a female receptacle from your generator into which you plug your shore cord. If your generator
provides 2 hot legs, you use your 50 amp cord, no adapter. If it's single hot, you use a 30 amp receptacle and use the dogleg adapter.

Now, if you want the generator to be wired into the system so it's automatic, then you have another problem for which we don't have enough information. Also, I
don't recall if you have an inverter in the system, and I'm too lazy to go look at the beginning of the thread, but regardless, you need to be concerned about neutral-ground
bonding/unbonding. This can be handled inside the receptacles if you go with a strictly manual source selection.

[Lin]

Gumpy- Did you mean 6/4 cable for the 50 amps?

Tikvah- Don't be sensitive about the suggestion to get help.  The knife switch, or any switch for the matter, is a bad and dangerous idea.  It is only reasonable when someone seems attached to that type of idea for others to recommend getting help.

If you do it as a straight 50 amp/240v system, as Craig outlined, it's all good.  If you want to do it as a 120v system, only run one hot giving you a three wire shore cable as mentioned by some earlier.  Your jumper wire will be okay then.  That's the way my last bus was.  The only added issue would be making sure your generator is set up for 120v only.  That is also easily done.

[gumpy]

Gumpy- Did you mean 6/4 cable for the 50 amps?

Yes. Good catch. Been a few years since I hooked this up. Brain fart.

I'll modify my post...