Plug in Motorhome at house ?

[Bob Hyatt]

Here's the true skinny. Neutral and ground need to be connected at ONE point in the home (not RV) wiring. The house neutral/ground is normally done in the power distribution center (breaker box). You shouldd see a large uninsulated copper wire outside the house. That generally goes to the bare ground in the meter or breaker box, but not both.

The problem is that you need your neutral wire to go to the breaker directly, and the breaker has its own ground so that it can measure the current flow through the hot wire and make certain it matches the flow through the neutral wire. If there is a mismatch, then there is a short somewhere and it will trip, realizing that hot to some internal ground is allowing part of the current to flow that way.

For example, when I wired my house for a 7.5K emergency generator, I had to modify the generator to have an open ground, since my house already has neutral/ground connected in the box. I can't safely use that generator to power my coach since the coach is also wired "floating neutral" expecting an external ground-to-neutral connection. My house provides that, as do the campgrounds in the power from the pedestal (unless they are in national/state/local codes violation. Main thing this will screw up is GFCI operation if you get it wrong.

[rbguinn]

A 50 amp receptacle has two separate 120v legs...a total of 240 volts. More amp flow is required for 50 amp RVs in full operation and is the reason the wires are are larger diameter from the post to the rv. To charge batteries only and slowly, bones & a smaller diameter wire is all that is needed.

[rarebear.nm]

Originally Posted by Flyin4Fun

I was going through the tedious effort of trying to find a GFCI problem. Ultimately, I decided to swap out the GFCI breaker that had been tripping. Voila'... problem solved! I did not know (or even think of it) that a GFCI breaker would become weak and/or start to fail. But apparently that is what happened in this situation.

Sent from my Pixel XL using iRV2 - RV Forum mobile app

They sure do fail. As I noted in Post 27, they have about a 10 year life and can fail any time. Glad you nailed it.

[rarebear.nm]

Originally Posted by Bob Hyatt

Here's the true skinny. Neutral and ground need to be connected at ONE point in the home (not RV) wiring. The house neutral/ground is normally done in the power distribution center (breaker box). You shouldd see a large uninsulated copper wire outside the house. That generally goes to the bare ground in the meter or breaker box, but not both.

The problem is that you need your neutral wire to go to the breaker directly, and the breaker has its own ground so that it can measure the current flow through the hot wire and make certain it matches the flow through the neutral wire. If there is a mismatch, then there is a short somewhere and it will trip, realizing that hot to some internal ground is allowing part of the current to flow that way.

For example, when I wired my house for a 7.5K emergency generator, I had to modify the generator to have an open ground, since my house already has neutral/ground connected in the box. I can't safely use that generator to power my coach since the coach is also wired "floating neutral" expecting an external ground-to-neutral connection. My house provides that, as do the campgrounds in the power from the pedestal (unless they are in national/state/local codes violation. Main thing this will screw up is GFCI operation if you get it wrong.

Bob, good details except one point. "the breaker has its own ground so that it can measure the current flow". GFCI breakers do not have a ground but do have a neutral lead. Usually a coiled white wire at the bottom of the breaker. Your description is otherwise good. Perhaps small detail, but electrical is in the details.

[Mudfrog]

On topic, and this is just my opinion.

I have never left the coach plugged in while parked at home. Just see no need in working the converter/charger for no reason. I don't want to have to worry about the charger boiling my batteries dry (it's old) or something going awry that burns up something in the electronics. And while i know it's not much, i don't want to pay for the extra electricity this would use anyway. For my situation, the pros for leaving disconnected outweighed the cons of keeping plugged in.

I did just recently install 30 amp service out to the rv port and have since made a change to my procedure. Instead of disconnecting the batteries like i used to do, i decided to connect service once a week. Installed a timer (with battery back up) and set it to turn on on Fridays and then shut off 12 hours later. Plugged a night light in and positioned it near one of the windows so i can see from a distance when power is applied. I think this is going to end up working out best for our situation.

[Winemaker2]

Originally Posted by Mudfrog

On topic, and this is just my opinion.

I have never left the coach plugged in while parked at home. Just see no need in working the converter/charger for no reason. I don't want to have to worry about the charger boiling my batteries dry (it's old) or something going awry that burns up something in the electronics. And while i know it's not much, i don't want to pay for the extra electricity this would use anyway. For my situation, the pros for leaving disconnected outweighed the cons of keeping plugged in.

I did just recently install 30 amp service out to the rv port and have since made a change to my procedure. Instead of disconnecting the batteries like i used to do, i decided to connect service once a week. Installed a timer (with battery back up) and set it to turn on on Fridays and then shut off 12 hours later. Plugged a night light in and positioned it near one of the windows so i can see from a distance when power is applied. I think this is going to end up working out best for our situation.

I think we are in the minority - many will say just plug it in -

I also avoid plugging in and running inverter / converter to keep battys up while in storage for similar reasons. If something goes wrong - batty cell shorts and draws hi amps etc I'm not around to monitor. Stoarage is a little ways away so don't want to bother w/ timers & checking constantly etc.

I like and use batty maintainers for all of my boat & MH battys. They draw 1 - 8 amps max and I never worry about hi current flows. I have one 2-4-8 amp maintainer for the house bank and a 1.5 A one for the chassis. I've wired them with a permanent extension cord so all I do is plug it in at the storage location.

With both house & chassis disconnects it doesn't take much to maintain a full charge on battys and because I only use a lo amp maintainer the storage place doesn't charge me for power usage.

[wa8yxm]

Originally Posted by Winemaker2

I see this type comment often and its just a pet peeve...
What is a simple 110V cord or circuit.

Though I share your peeve, and it's 120 volts now days has not been 110 since what. the 1960's.

I have several cords and connectors and adapters in this RV

Some places the only outlet is a 15 or 20 amp standard house type outlet (IE: some moose lodges) and sometimes it is a long way off.

I have several cords
50 amp shore cord. plus 50 amp extension
30 amp shore cord, plus 30 amp extension
Several 15 amp cords including a 100' 12ga from Sears/K-Mart

Those (The last line) are the "Simple 110 volt cords"

The Converter is a plug in version on this RV. it has a 20 amp plug so I have an adapter 20-15 I use with that cord and power JUST the Converter. nothing else is even connected.

[Bob Hyatt]

Originally Posted by Winemaker2

I see this type comment often and its just a pet peeve...
What is a simple 110V cord or circuit.

Common home & RV circuits are all 120V unless you are talking abour 240V for stoves, ovens etc.

Both come in different amperage ratings based on the wire size, component (recepticles, plugs...) rating and breaker rating.

Common house & RV recepticles are 120V 15A. Some 120V 20A and the RV inlet frequently 120V 30 A.

Why do folks refer to the above as 20A 30A or just 120V? They are all 120V?

The exception is the larger modern MHs that have 240V 50A inlets.

If we are going to quibble ( ) my home has exactly 125v ac at every outlet in the house, measured by a high-quality meter (two in fact). Almost every circuit in my house is 20a a, except for the A/C connections that are 30, and the stove which is 50a. I actually don't know the voltage for those high amp circuits. They can be connected single-phase with one side 180 degrees out of phase with the other (as a typical home generator works and as I believe my house is wired) or it can be connected to three phases from a transformer where each phase to neutral is 125vac, but any two hot phases is now only 120 degrees out of phase and you get more like 208 or so since the two peaks are never dead opposite each other.

Alabama power seems to have settled on 125v ac. I have at least checked two different transformers, which is all that determines this. And they generally have multiple tap points they can choose from if the need to go up or down due to cable length and such...


Someone mentioned that there is no such thing as a 5 amp circuit. You can have any amperage limit on a circuit you want.. OLD houses might still have the old fuses and my grandad kept a stock of 5, 10, 15 and 20 amp fuses. It is more about what you are trying to protect. I have SEVERAL 5 amp circuits on my boat, for example.

As far as my tiffin, I don't own two shore cords. There is NOTHING that needs 208-250vac in the coach. I use a dog bone that simply takes the hot side of that 30a circuit and ties it to BOTH hot sides of the 50a amp circuit so both sides have 30a shared between them. The RV doesn't need to use both sides at the same time unless you actually install something like an electric stove (NOT one of the inductions I don't think they pull that much excessive power). If you were to try to wire a traditional Stove/AC (208v+) and used a dog bone to go 50 to 30, neither would work, because that would be a zero volt circuit. The phases would always be exactly matched up and you would always see the difference as zero, which wouldn't power much. You would still see hot to neutral at 125 of course...

All I use is (a) a 50-to-30 dogbone which has the usual female connector to mate up with the coach (everything but the ground is flat and all of those are parallel to each other (no angled or non-flat lugs. I also have a 30-20 adapter that simply takes the 30a doggone end and turns it into the traditional 120vac. Good for connecting to charger at home. Or for tuning most everything off and running ONE A/C. The cords are pretty expensive when you run four stranded copper connectors (required for two hots, a neutral and an earth ground). The doggone approach is way cheaper and works exactly as well.

[A Traveler]

Originally Posted by Mr_D

On mine it does limit the number of amps the inverter can pull to charge the batteries.

The inverter has nothing to do with charging the batteries. An inverter changes 12 volts DC to 110 volts AC. That’s it. It does NOT charge the batteries. The battery charger does that. The inverter and battery charger might be in the same box, but they are two distinctly separate circuits.

[twinboat]

Originally Posted by A Traveler

The inverter has nothing to do with charging the batteries. An inverter changes 12 volts DC to 110 volts AC. That’s it. It does NOT charge the batteries. The battery charger does that. The inverter and battery charger might be in the same box, but they are two distinctly separate circuits.

The charger, of a Inverter/Charger is integrated into the inverter in many ways. That's how it charges thru the same large battery cables that it draws current from.

Its like a AC/Heat pump.

[rbguinn]

Bob, to fully understand the difference between volts & amps compare the water pressure cities put into there water system. 60 to 65 psi is ideal just as 110 to 125 volts we get from electrical systems we plug into at different RV parks.
Now compare the size of a water hose & the amount of water you can get from each to the amps from a water source with the same water pressure. A 1/4" hose & a 3/4" hose both will have the same water pressure and the 3/4" hose will deliver lots more water....Just like a #6 copper wire will deliver 50 amps & a #14 common extension cord can deliver under 10 amps.
One can charge house batteries on as slow charge with a charger plugged into a 110 to 125 volt house outlet.

[Bob Hyatt]

Originally Posted by Bob Hyatt

Here's the true skinny. Neutral and ground need to be connected at ONE point in the home (not RV) wiring. The house neutral/ground is normally done in the power distribution center (breaker box). You shouldd see a large uninsulated copper wire outside the house. That generally goes to the bare ground in the meter or breaker box, but not both.

The problem is that you need your neutral wire to go to the breaker directly, and the breaker has its own ground so that it can measure the current flow through the hot wire and make certain it matches the flow through the neutral wire. If there is a mismatch, then there is a short somewhere and it will trip, realizing that hot to some internal ground is allowing part of the current to flow that way.

For example, when I wired my house for a 7.5K emergency generator, I had to modify the generator to have an open ground, since my house already has neutral/ground connected in the box. I can't safely use that generator to power my coach since the coach is also wired "floating neutral" expecting an external ground-to-neutral connection. My house provides that, as do the campgrounds in the power from the pedestal (unless they are in national/state/local codes violation. Main thing this will screw up is GFCI operation if you get it wrong.

One correction. You DO have to have neutral to ground when running on generator. In my house emergency generator, I had to disconnect the neutral to earth ground connection since that is in my home load center and has to be connected there so that GFCI outlets will work right. Mine doesn't need connecting in the genset because of this. But if I ever get the urge to use the generator for something besides my house, I have to re-connect neutral to ground or the GFCI outlets on the genset output won't work. And there is another obvious problem. You can have one voltage between the A phase hot and ground vs hot and neutral, and/or B phase, same deal. NOT what you want. So somewhere neutral and earth ground have to be at the same potential, where you do this depends on what the GFCI outlets have as a ground reference.

[Bob Hyatt]

Originally Posted by rarebear.nm

Bob, good details except one point. "the breaker has its own ground so that it can measure the current flow". GFCI breakers do not have a ground but do have a neutral lead. Usually a coiled white wire at the bottom of the breaker. Your description is otherwise good. Perhaps small detail, but electrical is in the details.

I agree. Typed too quickly...

I also missed on the post I just made where I corrected it. You can't just use a bonded neutral / ground at the pedestal, as when running on gen power, you still need a bonded neutral / ground since you might not have the pedestal connection. Typically done in the generator itself, where the transfer switch is between the genset and coach to keep that bond out of the circuit while on shore power or inverter.

These are really fairly complex systems until you look carefully, then you realize just how bright the people were that connected all these wires.

[Bob Hyatt]

Originally Posted by rbguinn

Bob, to fully understand the difference between volts & amps compare the water pressure cities put into there water system. 60 to 65 psi is ideal just as 110 to 125 volts we get from electrical systems we plug into at different RV parks.
Now compare the size of a water hose & the amount of water you can get from each to the amps from a water source with the same water pressure. A 1/4" hose & a 3/4" hose both will have the same water pressure and the 3/4" hose will deliver lots more water....Just like a #6 copper wire will deliver 50 amps & a #14 common extension cord can deliver under 10 amps.
One can charge house batteries on as slow charge with a charger plugged into a 110 to 125 volt house outlet.

that is the description that most every book on the subject I have seen uses. Volts = pressure, amps = volume. volts * amps = work down (power, watts, etc)...