I've NEVER Been So Mad at a CG!

[Sbrownstein]

Originally Posted by Mudfrog

So at the same time,, 200 amp 240 volt residential service gives you two 120 volt circuits, each able to support 200 amps. But since this is alternating current, it'll never be more than 200 amps at any instant in time. Hence, the reason not to add both legs to get a total.

Is this right?

No...it's not. You will get 200 amps at 240 or two circuits each with 200 amps at 120 and thus 400 amps at 120...all at the same time.

[Monacoach]

Originally Posted by Sky_Boss

UM...on 50 amp I can use all 3 ACs, my clothes dryer, my OASIS electric elements and a little bit more.

That's really no different then what i said. I dont need to be an electrical engineer to tell you that you require a 50 amp site . When asked if your coach is 50 amp or 100 amp maybe if you simply answered 50 amp without going into the nerdy details things would have went smoother for you.

[jsmmonaco]

i am not a techy, and 6 pages of L1, L2, phase this, phase that, 50 amp, 100 amp, neutral, alternating current, has given me a migraine..........so am i correct in assuming that since our bus has a 50 amp service, 50 amps is what i can draw from the pole without a breaker blowing?.................so if two air's, maybe the hot water tank, tv, couple of lamps, gets you close to 50 amps, adding anything more gets you a breaker pop.................maybe i am just being cautious, but if we are in a CG, on 50 amp, airs run, tv runs, lights run, hot water tank and refrig go on propane.............................a simple, basic response for dummies like me would be appreciated.................and if you are gonna bitch about a campground, NAME IT.........

[Sbrownstein]

Originally Posted by jsmmonaco

.............................a simple, basic response for dummies like me would be appreciated.................and if you are gonna bitch about a campground, NAME IT.........

No, it is better than that. You can run pretty much everything in your coach as long as the total amperage on each side of your panel doesn't add to more than 50 amps. Since you have two sides you can run up to 100 total. Generally the panel is built so that heavy loads are on opposite sides to make use of this.

Sorry, can't make it simpler than that because if you put everything on one side and draw more than 50 a breaker will pop, but the other side will purr along just fine.

My suggestion is that when you are on 50 amp...forget it!

[richard5933]

You guys all have it wrong. It's all based on the principle of 7.

https://www.youtube.com/watch?v=WGPMadwqPKQ

[cavie]

Originally Posted by SummitPond

I fully admit it has been 45+ years since I studied this stuff, so pardon me if my recollection is not quite correct and please set me straight.

In the above URL reference there's a statement "... it minimizes the current flowing through the power company's electric meter ..." which would lead me to believe that somehow you can "cheat" the electric company of income, which I find hard to believe they'd condone through their own metering.

Does the neutral even go through the meter? It's been a while since I've seen the back of a meter, but I seem to recall only two sets of prongs (total 4), one set for each 120V line.

Thanks for helping update me on this.

The neutral and ground does not get used by the meter. Forget you ever heard the term 100 amps available. An electrician will never laugh at you.

[Mudfrog]

Originally Posted by Sbrownstein

No...it's not. You will get 200 amps at 240 or two circuits each with 200 amps at 120 and thus 400 amps at 120...all at the same time.

Well shoot,, I said that in my earlier post but was told it was wrong. Like you said, doesn't really matter anyway. Was just curious, is all.

[KanzKran]

I made these a long time ago and thought they might be useful for explaining how loads are driven from a single-phase 120/240V feeder and panel, functionally the same as in a house or 50A RV supply pedestal and coach lighting and distribution panel.

In the first, a 120V 50A random load is on L1 and the neutral, with 50A coming in through L1 and returning to the transformer on N. 1/120th second later, the flow is reversed, with current coming in through N and returning through L1. On the right side, the same load is on L2 and N.

In the second sketch, there is an identical 50A load on both L1 and L2, with current in through L1, passing through the load to N, but current also comes from N and passes through the other 50A load to L2. On the right, is the simplified version where nothing actually passes through N other than through the bus bar in the panel. There is 0A through N to the transformer's center tap because the loads on each 'phase conductor' are exactly equal and therefore the current through each load is exactly equal (for illustration purposes, of course).

In the third, the loads on each leg are not equal, and the difference in current between them is carried by N. At this instant in time, there is 10A coming from L1 and 40A coming from the transformer's center tap through N, with 50A going back to the transformer through L2. 1/120s later current flow in all conductors is reversed. The current goes both ways through the neutral, which is why I don't care for the term 'return', as it spends just as much time as a 'supply'. Same with the two phase conductors L1 and L2 - unlike DC power, and hydraulics and HVAC systems for that matter, there are no supplies and returns in common AC power.

Last sketch is of a 115/230V dual-voltage induction motor, first connected for low voltage where both windings are connected in parallel and both windings 'see' 120V across them, with 7A current through each, and then connected in series for high voltage operation, and again both windings 'see' 120V and both pass 7A. The center connection could be connected to N, but no current would flow (and yes, I've tested this once when bored ), and the voltage is at or very near zero referenced to N. While a dual-voltage motor itself isn't relevant, the way the main windings are connected for high voltage is exactly the same as the second sketch (balanced load on each phase conductor), but with no connection to N since it's not needed.

One big takeaway is that for a 50A 120/240V shore power connection, there is no more than a nominal 50A available, but after the current drives the loads on L1 (+120V to 0V), it continues on from the neutral bus to drive the loads on L2 (0V to -120V), reversing direction of course every 1/120 second. Any imbalance in current is carried by the neutral as always. Any 240V loads just connect L1 to L2 with no N involvement (right side of last sketch).

They're labeled Edison 1 through 4 because Edison's original DC distribution system was a 3-wire system, to minimize energy loss while using as little copper as possible, and the current split-phase systems are still sometimes called Edison 3-wire systems even though they use alternating current. Old habits, I guess. But when the loads on L1 and L2 are relatively close, current in N is minimal, and therefore voltage drop in the wiring is also minimal.

[Mr_D]

I have a 240 volt dryer in my MH. When running I pull about 30 amps on each leg. Turn on more stuff like the floor heat or the 3 heat pumps it takes more.

[apatz]

You can educate ignorance, but stupid is forever.

[tcg]

Originally Posted by richard5933

You guys all have it wrong. It's all based on the principle of 7.

This the best electrical explanation ever, I use it all the time.

[sfinch43]

Top: Purchase a power protection system to ensure that you never plug into a dangerous situation. If plugs, receptacles or cables are getting hot they are overloaded and subject to failure. Failure can harm your RV's electrical system.
Bridging a 30 amp system to two 30 amp poles is a violation of the national fire code and national electrical code, for obvious reasons.
My advise is pack up and move on quick.

[wallynm]

Never explain- Never complain

[jaykris]

I'm as confused as a baby in a topless bar!
All I know is I have one 50a plug on my RV, I plug it in and it works things in the camper........

Do some rigs actually have 2 plugs on them?? I have never seen a hookup yet where one would plug in two plugs. Please dont anyone call me stupid, thats for my wife.....

Jay