Airstream Electrical System EXPLAINED with a diagram!!!

[mkarahashi]

Hi everyone,

I created this picture to help someone on Facebook get familiarized on what's connected to what. The diagram seems to be more popular than I expected so I am also posting it here in case it is of benefit to more people.

Couple of thing I am not familiar with are the Truma system in the Basecamps as well as solar panels. I anyone can tell me how they are connected, I can add them.

Also, if anyone sees a mistake, please let me know and I will be more than happy to correct & repost.

[stevejones]

The one change I'd suggest, is showing the circuit from shore power to AC outlets, the microwave, and AC units as separate from the circuit from the inverter, which only (normally) goes to the TV outlets and the outlet where the audio system is.

Steve

[mkarahashi]

Ah ok. I don’t have an inverter in my AS, so I wasn’t sure. The inverter enabled outlets are also shore powered, right?

[mkarahashi]

Version 2 with bit more on regular vs inverter circuit outlets cleaned up.

[OTRA15]

[from a layman's perspective -- all IMO -- FWIW]

Not all Airstream inverter installations are created equal, from what I have read.

Some "pass through" the shore power directly to the 120-volt inverter outlets and some do not, in which case the inverter outlets rely on the 12-volt batteries for their inverted power.

Whether a particular Airstream has a certain specific inverter installation is not possible to know without inspecting the actual installation of each inverter in each Airstream, from what I have read. [or "understood" to be more accurate . . . ]

This "randomness" factor introduces possibly fatal "wild card" and "joker" cards into the deck.

Not sure that one universal flow chart can cover all of the Airstream universe, and still be helpful for "understanding" without adding -- on its own -- further confusion into the discussion. Your second draft would seem to be heading in that direction in this layman's opinion, sorry to say. Of course, the confusion could be all mine, for which this layman apologizes.

PS -- "inverter pass through shore power" search results: https://www.google.com/search?q=inve...=airforums.com
PS2 -- The typo in the headline is not helpful IMO.

FWIW

[oldenavy]

One other correction. Shore power does not pass through the converter, it is wired directly into the breaker panel (except for dual-inlet 30A units where there is a transfer switch). The converter is plugged into an outlet on the back of the breaker panel. If it senses shore power available, it charges the batteries & supplies power to the 12V system. Without shore power available, it does nothing.

[Dennis C]

I’d add USB ports to the diagram.

It looks like your diagram indicates that you can run the air conditioner using the inverter. Am I reading that correctly? I don’t believe that this is true.

[73Safari]

Hi all,

Since we are talking about electrical diagrams, and the one that MKarahashi posted is awesome and clear and only going to get better with the great feedback of this forum, I've got a puzzling dilemma however.

We have a 1973 Safari 23' Dual Axle Twin - Up front near the door there are two power switches close together and another about two feet away to the front. I've identified the one switch closest to the front as the on / off to exterior spotlight. I've identified one of the other switches near the door as the on / off to the exterior door light. Can't figure out what the 3rd on / off switch is for? I'm thinking it could be the on / off for the vintage sensor dashboard which is located up front over the radio and when it worked back in the day, had all the sensors for the various water tanks, septic etc reporting in.. FYI - All of those systems have since been removed in our renovation - Septic tank, Fresh water tank, furnace, water heater, plumbing etc, all removed. So no need for the dashboard except as a 70's vintage visual which we will keep. Any thoughts on this? Am I correct in my assumption or could this switch be for something else? i've checked the '73 service manual and it's not in there.

Thanks in advance!

Mike

[CBWELL]

I believe that the diagram should also show a 12 volt supply to the A/C unit. This supplies the voltage to the circuit board. In my 1994, if there is no battery power, the A/C will not operate. Excellent diagram to carry with you in the trailer. Thank you for posting!

[kittmaster]

I would add that in my 2019, the ACs and microwave do not operate regardless of the inverter. Your diagram shows that they would operate if the inverter is turned on, which is not the case. The inrush power demand to run the microwave and or the AC's would crush the AGM batteries in short order.

[OTRA15]

Originally Posted by 73Safari

. . .
. . . I've got a puzzling dilemma however.
. . .

Welcome to the forum, Mike. May I suggest that you start your own thread, by clicking on the "New Thread" button here?

https://www.airforums.com/forums/f37/

Thanks.

[73Safari]

Thanks, and i thought about that prior to posting but thought I'd limit the noise and consolidate under an existing discussion of similar context. But got it out there now. Take care, Mike

[OTRA15]

Thanks for the new thread . . . good luck with your situation.

https://www.airforums.com/forums/f37...ch-222104.html

[mkarahashi]

Thank you to everyone for the great feedback, corrections, and comments.

This started out as a picture to help a new AS owner understand what they can turn on via 12v versus what needs shore power. The furnace/fridge was really messing her up. She described herself as a visual learner, so I drew a picture for her. Then the engineer in me started tweaking it to make it better. The issue is that this picture has become a tweenager - it’s trying to be too detailed for it to be a “picture” but it’s too inaccurate to be a “diagram”.

Perhaps what I should do is just take out the inverter. That will solve a lot of the issues, not to mention, as one of you said, there’s so many variations out there on how inverters are actually wired.

I should also put in big bold letters that this is a concept diagram, not to be used as schematics for actual wiring.

@OTRA15 - I’m laughing at myself about the typo in the title. Worst yet, it looks like the title can’t be changed after the fact. I guess I will forever be associated to that typo.

@oldnavy - good catch! I was doing this from memory of what I saw when I installed a hardwired surge protector. Should be an easy correction I can make.

@Dennis C - I thought about USB ports but I wasn’t sure if those are 12v or 110v powered. I installed a 110v outlet with USB built in that I picked up from Home Depot (may be it was Amazon), so that’s obviously 110v powered. However, I’m under the impression (out of nothing but my imagination/expectation) that factory USB outlets are 12v powered. If you can help me confirm that, I’d be happy to add USB outlets since I’m sure that’s an important one for a lot of people.

@CBWEEL - I didn’t know air conditioner uses for it’s small electronics. I imagine the thermostat might be 12v, or may be powered by small current from the air conditioner. On a similar note, I left out 12v connection for the water heater which actually really needs it. But in either case, the main “power source” for the air cond or water heater isn’t 110v so I think it’s ok to leave it out as long as I make the main purpose of this diagram (it’s a concept picture, not emanated to be used as schematics)

@kittmaster - agreed. I’d be surprised if the microwave is connected to an inverter enabled outlet. I tried to clarify that distinction in the second version. And I’d imagine the AC, in reality, is hard wired to 110v and it’s not “plugged in” to any outlet. Let me see if I can clarify that more.

Ok… let me see if I can incorporate all these comments into a third version!

Thanks everyone.

[uncle_bob]

Hi

I would consider some sort of color code. One color for 120V wire, the other for 12V wires.

Some Airstreams are set up for 30A shore power and others for 50A. That impacts the diagram at some level.

As noted, there are a lot of things that get 12V to keep them going. Having both a 12V and a 120V line into something may get a bit confusing.

The "trailer brakes" themselves do not run off of the battery. They like the turn signals and backup lights run off of the 12V power from the TV. The break away switch does indeed power off of the battery, but that's only in an emergency.

As normally wired the 7 pin from the TV has a lead that goes to the AS battery bank. Like a lot of the 12V stuff it goes through thermal breakers. One might want to include those.

If the trailer has electric awnings, they get into the 12V diagram.

If the trailer has a sub-woofer, it normally has it's own 12V connection.

Lights in the storage compartments might be worth noting. If they are left on accidentally they normally can drain the battery.

The use / store switch gets a lot of people confused. Getting it into the mix might help un-confuse people. The same is true with the disconnect switch on the newer trailers.

Yes, this can go on and on.

Bob

[kittmaster]

I can confirm that the USB are in fact 12V operated as I've added more to my AS as well as 12 cig lighters T'ing off the same circuit.

[Hittenstiehl]

The final version will be very helpful!

[ATaber]

Wow!! Great diagram. It helps me and will really help me explain the electrical system on our 2018 FC 25FBT to my wife. Adding all the comments above including the power from the TV will be great.

Any chance you can post the file with the diagram? Then we could each download make our own notes that would relate to our trailer and any modifications we make? Thought I would just ask. If not possible I can make one based on your excellent diagram.

Thanks
Andy

[mkarahashi]

Ok, version 3. Some change I made (thanks all for all the inputs)


1. Added title to clarify intent of this diangram
2. Corrected shore power to not go through converter
3. Tried to clarify inverter vs normal outlets
4. Added USB outlet, electric awning, subwoofer to 12v
5. Added tow vehicle 7-pin with note to clarify power for brakes
6. Other smaller corrections

Original file can be found here. This is slide 5 in the file

https://docs.google.com/presentation...d0756d16c9_0_0

If there are other corrections or suggestions, please let me know1

[Dennis C]

Originally Posted by kittmaster

I can confirm that the USB are in fact 12V operated as I've added more to my AS as well as 12 cig lighters T'ing off the same circuit.

Yup. Same here.