What was Airstream thinking?

Green on 12V is NOT generally accepted as a NEGATIVE wire, period.

Bad form, followed by more bad form = epic fail.

RV 12V wiring uses WHITE for the negative, no other colors are used for that purpose.

All other colors including black are 12V POSITIVE..

What I would have done instead of all the haphazard hacking would be to run a new run using typical RV 12V wiring colors (white is neg and black or other colors are positive) from the 12V outlet to the CONVERTER fuse panel OR directly to the battery. I would have used 14 ga wire for a short run and possibly 12 ga wire for a longer run just to keep the voltage drop to a minimum.

At the converter I would have connected the negative directly to the negative terminal on the 12V FUSE PANEL. IF the fuse block does not have a negative terminal I would have traced the 12V negative out the BACK of the panel and then SPLICED there.

I would NEVER, EVER consider using the 120V side of the panel for this type of modifications even though the ground terminal in the 120V side is at the same potential it is not a good idea..

To put this another way, the 120V ground is for SAFETY, there is a BONDING wire that goes to the frame. This wire is typically 10 ga or 8 ga and is there only to ensure all metal of the trailer will be at 120V ground potential.

It is bad form due to the fact that someone else who is not familiar with YOUR modification may mistake that fake green wire for the wrong use.

While YOU don't see the error of your ways and feel it is "safe" you are voiding any and all NEC rules on keeping separation between 120V and low voltage systems just by having that fake green wire running into the 120V box..

OP here. I will try to address all of the questions/issues.

itguy08 wrote:
How is connecting 12V and 120V grounds safe???? If the 120V uses the ground as the neutral you'll be sending 120V into the negative power path of the 12V system right? (assuming it's negative ground like a car)

They are already connected. They have to be. I am just taking advantage of that. If that kind of short occurs, all of your 12v stuff already will be energized.

Gdetrailer wrote:
In practice however, it IS bad form to MIX high voltage (120V) and low voltage (12V) systems in side the same junction box..

The converter power panel is designed to maintain separate high voltage and low voltage sections and for good electrical practice the OP SHOULD MOVE the 12V NEGATIVE connection from the 120V section.

The OP needs to look BEHIND the power panel, there WILL be a bundle of 12V NEGATIVE wires (these wires should all be WHITE) all connected via one huge wire nut..

Low voltage connections (in the past, not sure if that is true now days)were/are treated differently by NEC in the fact that there was no requirement for a enclosed junction box for low voltage connections..

That's where the OP should have tied in at..

Every word of this is true. I admit, it is bad form. However, it is, electrically speaking, identical.

Gdetrailer wrote:
Pretty much a total waste of time and materials.

I would have simply downgraded the fuse to meet the 18ga wire fusing requirements.. 7.5A would have been the correct fuse size..

Those outlets are merely put in as a CONVENIENCE to allow SMALL LOW CURRENT 12V devices to be plugged in.

Things like small 12V TVs(12"-15" and under 4A draw), portable radios, chargers for cell phone, laptops, tablets..

Was not designed for high current draws for things light 1200W inverters, 50" plasma TVs and full on concert level sound systems..

The 12V cig outlet you typically find can only handle a max of 8A (EIGHT AMPS) at 12V which comes out to a whopping 96W..

If you NEED higher current draw then I would suggest looking at marine 12V outlets, I believe they can be found with up to 15A current ratings but you would also need to make sure the PLUG you use is also rated for that draw..

Every word of this is true except for it being a waste of time and materials. The power point came with a 3 foot wire, and I needed about 12 feet to do what I wanted. I had to run my own wire anyway, so I just ran 12g all the way. I don’t plan to run plasma TVs from it, but it is capable. The only planned use is a rechargeable razor and a laptop computer.

itguy08 wrote:
Bad wording on my part - what I meant was in a failure scenario where the neutral is not working and the ground becomes the neutral (as its designed to) wouldn't you be sending 120v to the 12v side?

You already are. When the RV was built, the 120v GROUND and the 12v GROUND were already tied together electrically. They all are built that way.

Gdetrailer wrote:
The only issue I see is the OP decided to put a 12V DC negative wire into the 120V side of the converter and connect it to the 120V GROUND BUSS BAR terminals.

The 12V negative wire is WHITE, 120V ground wiring is supposed to be only GREEN (covered) OR BARE wires..

Placing a white wire on the ground buss bar is a potentially confusing situation that may lead to someone eventually MOVING the 12V negative wire to the 120V NEUTRAL BUSS BAR in the future!!!

I used a green ground wire. Anyone looking into the 120v side will see a ground wire on the ground wire buss.

Gdetrailer wrote:
NEC also insists that there is a PHYSICAL separation between 120V and low voltage 12V.. That is why the 120V section has a separator between the 120V breaker panel and the 12V fuse panel and ALL 120V is in the breaker section and ALL 12V wiring is in the FUSE section..

OP VIOLATED the 120V VS low voltage 12V separation by placing a 12V wire INSIDE the 120V breaker section of the converter and making matters worse, a WHITE wire connected to the ground BUSS bar.

Yes. I have acknowledged that it is bad form, but like I said above, I used a green wire.

Gdetrailer wrote:
NEC does have different rules on handling 120V vs 12V in how the wiring is done.

As I mentioned before, OP NEEDS to disconnect and move the 12V negative wire OUTSIDE the 120V side (breaker panel side) and find the 12V negative pigtail (all low voltage white wires connected together in a bundle) that should be BEHIND THE CONVERTER in order to make the proper connection..

Yes. That would be better form, but would it work any better?

Walaby wrote:
OP should correct the wiring snafu. If he ever sells it, might create an issue for the new owner.

Mike

What kind of issue could it create? A new user will see a green ground wire on the ground buss. I am not being facetious here. I really would like to know if I am overlooking an issue. If so, I will fix it, but I can see no issue other than it being bad form.

OP should correct the wiring snafu. If he ever sells it, might create an issue for the new owner.

Mike

there goes airstream

If Air Stream left it off it is because the folks were not using it enough to justify putting one in every TT.

Those who use it will get one installed or do it themselves.

Air Stream in the meantime can spend the money on some other "frilly" they think the customer will like.

The TT industry has not put LP lamps in TTs for decades but I still think they were a good idea. Some of my LP gas mantel lamps are ready bright, unfortunately that are quite hot also.

Times and tastes change.

itguy08 wrote:

budwich wrote:
actually, the part that's bad is the part about "If the 120V uses the ground as the neutral"... that's the big no no.

Bad wording on my part - what I meant was in a failure scenario where the neutral is not working and the ground becomes the neutral (as its designed to) wouldn't you be sending 120v to the 12v side?

Since the 12V BATTERY NEGATIVE TERMINAL is connected to the FRAME AND THE 120V SAFETY GROUND is connected to the SAME FRAME, all 12V stuff will have the same ground potential.

That IS how a RV is wire together.

The only issue I see is the OP decided to put a 12V DC negative wire into the 120V side of the converter and connect it to the 120V GROUND BUSS BAR terminals.

The 12V negative wire is WHITE, 120V ground wiring is supposed to be only GREEN (covered) OR BARE wires..

Placing a white wire on the ground buss bar is a potentially confusing situation that may lead to someone eventually MOVING the 12V negative wire to the 120V NEUTRAL BUSS BAR in the future!!!

NEC also insists that there is a PHYSICAL separation between 120V and low voltage 12V.. That is why the 120V section has a separator between the 120V breaker panel and the 12V fuse panel and ALL 120V is in the breaker section and ALL 12V wiring is in the FUSE section..

OP VIOLATED the 120V VS low voltage 12V separation by placing a 12V wire INSIDE the 120V breaker section of the converter and making matters worse, a WHITE wire connected to the ground BUSS bar.

NEC does have different rules on handling 120V vs 12V in how the wiring is done.

As I mentioned before, OP NEEDS to disconnect and move the 12V negative wire OUTSIDE the 120V side (breaker panel side) and find the 12V negative pigtail (all low voltage white wires connected together in a bundle) that should be BEHIND THE CONVERTER in order to make the proper connection..

budwich wrote:
actually, the part that's bad is the part about "If the 120V uses the ground as the neutral"... that's the big no no.

Bad wording on my part - what I meant was in a failure scenario where the neutral is not working and the ground becomes the neutral (as its designed to) wouldn't you be sending 120v to the 12v side?

Bobbo wrote:
Just because Airstream didn't think the 2017 Flying Cloud 23FB needed 12v outlets doesn't mean I think it doesn't need them! (I leave it laying at the bottom, back of the wardrobe till I need it.)



The 12v outlets came with a 15 amp inline fuse on 18g wire. I cut off the inline fuse since I wired it to an empty slot on the 12v distribution board with a 15 amp fuse. I cut the 18g wire as short as I could and butt connected it to 12g wire (seems like that is all Airstream used, the wide spot in the wire right in front of the shelf are the 2 butt connectors, staggered so they are not too wide). Like I said, I ran the hot wire to an empty slot on the 12v board, and ran the ground wire to the ground wire buss in the 120v side of the breaker panel (be sure NOT to use the neutral buss). The 120v ground buss is connected to the 12v ground. The wardrobe that it lives in is only about 2 feet from the breaker panel/fuse box and on the same side of the trailer.

Pretty much a total waste of time and materials.

I would have simply downgraded the fuse to meet the 18ga wire fusing requirements.. 7.5A would have been the correct fuse size..

Those outlets are merely put in as a CONVENIENCE to allow SMALL LOW CURRENT 12V devices to be plugged in.

Things like small 12V TVs(12"-15" and under 4A draw), portable radios, chargers for cell phone, laptops, tablets..

Was not designed for high current draws for things light 1200W inverters, 50" plasma TVs and full on concert level sound systems..

The 12V cig outlet you typically find can only handle a max of 8A (EIGHT AMPS) at 12V which comes out to a whopping 96W..

If you NEED higher current draw then I would suggest looking at marine 12V outlets, I believe they can be found with up to 15A current ratings but you would also need to make sure the PLUG you use is also rated for that draw..

actually, the part that's bad is the part about "If the 120V uses the ground as the neutral"... that's the big no no.

itguy08 wrote:

Bobbo wrote:
Like I said, I ran the hot wire to an empty slot on the 12v board, and ran the ground wire to the ground wire buss in the 120v side of the breaker panel (be sure NOT to use the neutral buss). The 120v ground buss is connected to the 12v ground.

How is connecting 12V and 120V grounds safe???? If the 120V uses the ground as the neutral you'll be sending 120V into the negative power path of the 12V system right? (assuming it's negative ground like a car)

Even though it sounds "bad", in reality the 120V AC equipment ground IS bonded to the trailer frame.

At the same time the 12V NEGATIVE terminal is ALSO BONDED to the trailer frame.

So in a sense does not matter as to where you find a place to tie in for 12V NEGATIVE.

In practice however, it IS bad form to MIX high voltage (120V) and low voltage (12V) systems in side the same junction box..

The converter power panel is designed to maintain separate high voltage and low voltage sections and for good electrical practice the OP SHOULD MOVE the 12V NEGATIVE connection from the 120V section.

The OP needs to look BEHIND the power panel, there WILL be a bundle of 12V NEGATIVE wires (these wires should all be WHITE) all connected via one huge wire nut..

Low voltage connections (in the past, not sure if that is true now days)were/are treated differently by NEC in the fact that there was no requirement for a enclosed junction box for low voltage connections..

That's where the OP should have tied in at..