30 amp breaker

[kcmusa]

what if someone tied both mains together inside the box. something we cant see. Now we can have 30 amps on either side.

[5picker]

Originally Posted by kcmusa

what if someone tied both mains together inside the box. something we cant see. Now we can have 30 amps on either side.

Actually... in this case... if someone tied the two busses together inside the box, it would be the PERFECT thing to do. Then, any load of more than 30a (regardless of which side or combination of) would trip the R/V's double main breaker.

But alas we can't see the inside of the box... we don't know if they are using an adapter... and the 'what ifs' continue...

[cavie]

Originally Posted by 5picker

Actually... in this case... if someone tied the two busses together inside the box, it would be the PERFECT thing to do. Then, any load of more than 30a (regardless of which side or combination of) would trip the R/V's double main breaker.

But alas we can't see the inside of the box... we don't know if they are using an adapter... and the 'what ifs' continue...

Well, I hate to spoil the party but what you are looking at is a 120/240 volt 24 circuit sub panel. Probably of 80 or 100 amps

Is a sub panel because it has no main breaker. The 2nd clue to voltage is the 240 2 pole breaker at the bottom right. If you were to ty the 2 bus bars together you would have 4th of July in April.

[myredracer]

Originally Posted by cavie

There is no reason to change anything. It is perfectly safe and code compliant as long as you do not use a 50/30 dogbone.

Which is my suggestion except for using a marrette to split the #10 so there aren't two wires under a breaker terminal.

But thinking more about this (again), it does allow each bus in the panel to draw up to 30 amps each, or 60 amps total on the #10 incoming supply wire which clearly isn't good. Yes, as long as not using a 50/30 dogbone nothing will burn up but that's not very foolproof. And there are occasions you just have to use a 50 amp pedestal. Besides the 30 amps in a pedestal being in terrible condition sometimes, I've seen where a pedestal with 50 & 30 amps is shared for two sites and it's first come, first serve. And sometimes there can be a pedestal with 50 amps only. All depends on where you go camping.

The best thing would be to have a 30 amp main breaker in the panel but I can't see how you'd tie the two busses together without having two breakers in series. Maybe a 1p-30 amp breaker in a separate enclosure would work, except for the typical size of the enclosures.

Do any RV panels actually have incoming lugs and a separate main breaker? AFAIK, they all use a setup where a branch breaker is used as a main. Electrically accomplishes the same thing and is space saving.

[cavie]

My post was for kcmusa's picture. I hate using my phone. Looks like we are talking about two different panels

[5picker]

Originally Posted by cavie

Well, I hate to spoil the party but what you are looking at is a 120/240 volt 24 circuit sub panel. Probably of 80 or 100 amps

Is a sub panel because it has no main breaker. The 2nd clue to voltage is the 240 2 pole breaker at the bottom right. If you were to ty the 2 bus bars together you would have 4th of July in April.

I wasn't referencing the picture of the panel posted. I didn't post it. It was posted by someone else. I have no clue why the poster of that post chose that particular photo. I was only referencing to the accompanied text.

If you chose to read my post, I was referring to the panel being discussed in the OP and mentioned so.

[CedarCreekWoody]

In the original photo by the OP I was curious why the two 30 amp breakers were connected by the bar as either could function independently. It later occurred to be the bar assured that manually turning off the breaker would kill all breakers, not just half of them. Very interesting setup.

[cavie]

Yep. Figured that out.

[pdqparalegal1]

I can’t believe it took this many pages to explain this. When I see a post of over 3 ��pages I know it’s a discussion of opinions.

[monte]

The motor home was bought used and had an inverter and residential refrigerator added and possible some AC outlets added to the inverter. I haven't had time to research all of the outlets and haven't pulled any breakers to see what is behind them. But this certainly turned into a very interesting post. When I get time I'll try to post what I find. Thanks for the reply's.

[fonzie]

Originally Posted by monte

The motor home was bought used and had an inverter and residential refrigerator added and possible some AC outlets added to the inverter. I haven't had time to research all of the outlets and haven't pulled any breakers to see what is behind them. But this certainly turned into a very interesting post. When I get time I'll try to post what I find. Thanks for the reply's.

What is shore power supply, 30 or 50 amp plug in? If 50 amp it was probably modified from previous owner to provide 50 amp at 120 volts single line.

[cavie]

Originally Posted by fonzie

What is shore power supply, 30 or 50 amp plug in? If 50 amp it was probably modified from previous owner to provide 50 amp at 120 volts single line.

And if you did that you would be applying 50 amps on a #10 30 amp wire. Better keep a fire extinguisher handy!

[cavie]

Originally Posted by pdqparalegal1

I can’t believe it took this many pages to explain this. When I see a post of over 3 ��pages I know it’s a discussion of opinions.

A lot of these post were to correct some misinformation If the OP pulls the 30 amp 2 pole breaker it will all come to him. If the buss bar is not split that jumper wire would cause a hell of a short thru that 2 pole breaker. Any trained electrician can look at the pic and understand what is going on without removing any breakers.

[monte]

I am not a trained electrician or even an untrained one. I started this post because I have owned 3 class c RVs and have never seen one with a 2 pole 30A breaker and wondered what it was for. The shore power cable is 30A and everything looks original except for the residential fridge and inverter and wiring to and from the inverter.

[cavie]

Originally Posted by monte

I am not a trained electrician or even an untrained one. I started this post because I have owned 3 class c RVs and have never seen one with a 2 pole 30A breaker and wondered what it was for. The shore power cable is 30A and everything looks original except for the residential fridge and inverter and wiring to and from the inverter.

I don't think you will find two other people that have seen one either.

[jtmitch416]

"If the buss bar is not split that jumper wire would cause a hell of a short thru that 2 pole breaker." Wouldn't that just be a redundant feed from the same phase? Just trying to learn. Learned about the box being back fed today![emoji3]

[cavie]

Originally Posted by jtmitch416

"If the buss bar is not split that jumper wire would cause a hell of a short thru that 2 pole breaker." Wouldn't that just be a redundant feed from the same phase? Just trying to learn. Learned about the box being back fed today![emoji3]

I need to fix some misinformation that I provided in post #93. This whole thing has my head spinning. There would not be a short issue. There would be a very large wire heating issue if some one was to use a 50 amp dog bone. Again IF the buss bar is split. I wish we could edit our post at any time. Old men tend to engage the mouth before the brain sometimes. If the bus is not split and single pole breaker would have done the trick.

[cavie]

Originally Posted by jtmitch416

"If the buss bar is not split that jumper wire would cause a hell of a short thru that 2 pole breaker." Wouldn't that just be a redundant feed from the same phase? Just trying to learn. Learned about the box being back fed today![emoji3]

Every RV panel has a back fed main breaker. You have known it all the time you just didn't realize it. Go look at your RV electric panel.

[nomad297]

Originally Posted by cavie

I need to fix some misinformation that I provided in post #93. I wish we could edit our post at any time.

Cavie,

The Site Team can edit it for you if you ask. I suppose they would have to consider if editing your post would interfere with the continuity of the conversation, but in this case I think it would be beneficial.

Bruce

[formerFR]

Breakers don't care if they are 'backfed' or not - but RV's don't have the same typical design as a home because they are not permanently attached to utility power, which is the two main large wires that come from a power meter into your home, and into the top of your home's main panel.
An RV is using 'temporary' utility power, thru a Shore Cord, and many times also the ATS(automatic transfer switch) due to the additional power source - the generator.

Since an RV's main panel is NOT connected permanently, it doesn't have main 'lugs' to the buss bars that the breakers attach to. It uses a simple method of providing the buss bars with power by attaching the incoming power wires from the ATS to the front of each Main Breaker, which then provides the power to the buss bar(s). The breakers still work exactly the same, as they don't 'care' whether the power comes in, or out, just that the amount of 'heat', or amps, is what ultimately causes them to trip. A breaker is simply a switch. Your light switch doesn't care which way the power flows, but when you switch it 'off', or 'open' the connection, it loses power to the light. The same for the breakers, regardless of which 'way' the power is flowing, it simply 'opens' when the heat, or amps, exceeds it's design, shutting off the flow of power to the buss bar(s).

With a 30amp Main Panel, for incoming 120v power, it only has a single 30amp Main Breaker, with the power coming into it's front wire connection.
The main breaker is attached to a single Buss Bar, providing power to each individual breaker that is also attached to it. These individual breakers receive their power from this buss bar at the rear, and the front output of each individual breaker goes to the circuit that it supplies power to, just as you would imagine.

With a 50amp Main Panel, which incoming 240v power(two hot legs), it has TWO 50amp Main Breakers, joined with a common trip handle, with the incoming Red and Black hot legs of power coming into the FRONT of each main breaker, then flowing to the TWO buss bars the breakers are mounted on... one for each 'side', or leg of power. Most of these Main Panels have the two main breakers located in the middle, with the 'left' side of 50amp power provided to the individual breakers on the left, and the other 'right' side of 50amp power to the breakers on the right.
This provides up to 100amp of 120v power to the RV. The main panel is not designed to typically give the option of mounting double-pole 240v individual breakers because of this 'left/right' design. The vast majority of 50amp RVs don't have a need to use 240v power. The few that do have a panel that is designed differently - more like the 'vertical' panel at your home, because they have a large 'heat' appliance that requires it, such as a residential clothes dryer.

Some RVs with larger 'whole house' INVERTERS, which provide for residential 120v refrigerators, microwaves, and most outlets on the Inverter power, will require a 'sub-panel' for this power, since these outlets require not only the normal Shore Power and Generator power, but also the third power source, from the Inverter. Since the Inverter is not designed to provide power to air conditioners, the electric water heater, and other large draw devices, the sub-panel provides a way to have those outlets separated so that the Inverter can power them, and only them, when the power comes into the Main Panel. In this case, as in my coach, their is an additional 30amp individual breaker, with a 'front fed' power from the Inverter, to it's own separate buss bar, and to the individual breakers that serves the outlets.
So, when the coach is off-grid, the Inverter power all the outlets, including the fridge and microwave, etc. When the generator is started, the Inverter simply provides a 'pass thru' of this 120v power to these same circuits. The same when on Shore Power. This sub-panel allows all the outlets to have power from three different sources.

This 'sub-panel', though, is not a separate box, or separate panel, it is a special design that the factory purchases to be able to accomplish this in an easy-to-install single panel design. Mine is from Progressive industries. When you initially look at my main panel you would not necessarily think that it's anything more than any other 50amp main panel, though you would see both a 'Inverter/Charger' labeled breaker, on the left side, AND a 'Inverter/Main' labeled breaker on the right side... at first a little confusing.
It took me quite a while to realize that the left breaker provides 120v power to the Charger, which is integrated within my Magnum Inverter, from the generator or Shore Power, and the right breaker is the 'Main' incoming power to the sub-panel from the Inverter's output.

Many RVs with inverters would not necessarily have a similar setup because they may have a smaller inverter that is really only dedicated to the residential fridge, and the inverter does not have an integrated battery Charger... they already have a Converter which does the charging. The smaller inverter is also not wired into the main panel, but directly to the fridge, which is a simpler way to accomplish the ability for the residential fridge to have 120v power, even when off-grid. When plugged in, or using the generator, the 120v power provided to the Convert's battery charger offsets the usage of the inverter for the fridge.

You'll also find that if you do plenty of research, almost every factory does things differently, even sometimes the same factory does things differently for different models and floor plans of RVs they produce.