What is this and how do I hook a cpap to it

[Stryker Guy]

Need to hook a cpap to the DC system. Not directly to the battery. Thoughts?

[TacomaJoe]

It looks like a DC distribution system. Big red wire feeds bus to 6 resettable breakers. I would pull from the main (big red) terminal and use a new fuse to the CPAP. Does the CPAP run on 12VDC and do you have a negative terminal?

[Stryker Guy]

Cpap has a 12v adapter. The Negative is to the frame nearby so I could just clip to the frame

[NavyLCDR]

That looks like a homemade DC power distribution panel.

[chriscowles]

Originally Posted by NavyLCDR

That looks like a homemade DC power distribution panel.

It looks more like very badly designed factory power distribution panel just inside the frame. My (and others') Rockwoods have the same basic electrical box with a couple of auto-reset breakers outside it. This just has more breakers.

Edit: interestingly, it uses a cheap steel strip as a bus bar feeding power to all the breakers. As rusty as it is I would not be surprised if they all had really high resistance at the bus bar connection. At a minimum I'd disassemble that, sand the rust off it and use some kind of anti-corrosion coating that doesn't interfere with conduction. Better yet, figure out how to house that in a protected box.

[moose074]

I use inverters like the Ryobi and older battery box jumper that has inverters

[Stryker Guy]

Originally Posted by NavyLCDR

That looks like a homemade DC power distribution panel.

Factory installed. I bought the trailer new. I am not impressed with the wiring exposed like this. It is a fall project to clean up and enclose.

[Aussieguy]

can't be a steel plate

if it is......... then all of the breakers would not do anything as they would be jumped.


now that I got home and can use my computer
looks like some sort of dirt or sawdust making it look rusty (photoshop zoom)
the rust color is on the wire insulation material and on the floor of the compartment



More than likely it's a circuit board material and a strip of conductor material underneath?




certainly looks like a rusty plate on mu phone and ipad small screen
when I first saw it on the Ipad.... I was thinking it was steel and immediately said to myself that can't work.

[Aussieguy]

additional ... don't trust that black to be a negative

test it with a meter or look underneath


Cpap you should be able to tap into one of the breakers and find the correct negative (frame)

[5picker]

Originally Posted by Aussieguy

additional ... don't trust that black to be a negative

test it with a meter or look underneath


Cpap you should be able to tap into one of the breakers and find the correct negative (frame)

How could one even consider that black to be a negative when it's connected to a 12v circuit breaker post?

[bubbles]

Originally Posted by Aussieguy

can't be a steel plate if it is......... then all of the breakers would not do anything as they would be jumped.

HUH?

[chriscowles]

Originally Posted by Aussieguy

can't be a steel plate

if it is......... then all of the breakers would not do anything as they would be jumped. ...

It is conductive. It's a bus bar tied across one side of all breakers. Note the single positive wire coming from the junction box. That supplies power to all breakers, each of which has a separate wire on the opposite pole, feeding a separate device or circuit.

[Aussieguy]

Originally Posted by chriscowles

It is conductive. It's a bus bar tied across one side of all breakers. Note the single positive wire coming from the junction box. That supplies power to all breakers, each of which has a separate wire on the opposite pole, feeding a separate device or circuit.

would not the steel make a connection between each/every post ?
breakers would all be "jumped" and they would not "trip" the circuit as expected.

first real quick glance though there was a black negative...
does not hurt to warn someone to check it?



WAIT ....
I see it now...
the conductor is only half way across the breakers
I need stronger glasses!

[NavyLCDR]

Originally Posted by Aussieguy

would not the steel make a connection between each/every post ?
breakers would all be "jumped" and they would not "trip" the circuit as expected.

first real quick glance though there was a black negative...
does not hurt to warn someone to check it?

The steel, aluminum, or copper buss bar in the photo is only connecting circuit breaker inlet sides together. There is nothing external between the inlet and outlet terminals on any of the circuit breakers, nor is there anything connecting any of the outlet side terminals together.

The black wire is attached to the outlet terminal of one of the circuit breakers. In order for that to be a ground wire, the entire string of circuit breakers would need to be ground, and that would be a major wiring mistake that not even an RV manufacturer should make. Checking that wire for connection to ground is as unnecessary as pulling a wire off the positive terminal of the battery and checking it for ground. But, if it floats your boat....

[chriscowles]

So, back to the original question. One of those breakers is probably a power jack or a slide-out motor. Both are used only intermittently. Either would be fine, in general, as a power source for an accessory outlet to use with CPAP.

Take care that you don't break off a post when attaching a new conductor. If you do, you'll have to disassemble the entire setup to fix the one you broke. In the process, you might break others. I wouldn't touch that unless prepared to rebuild the whole thing.

If you decide to use that as a power source, the remaining details depend on where your bed is located, relative to it. Get the current specs from your CPAP and use the calculator at wirebarn.com to determine the correct wire size. You'll need a fuse on the wire, close to the power source.

When I added an accessory outlet for CPAP in my previous hybrid, the bed was at the front. Being close to the batteries on the tongue, I just ran a 16 ga stranded pair directly to the battery, kept it as short as possible. I added an inline fuse inside the battery box. I did not rely on the fuse that came with the 12V accessory port. It was close to the device, leaving most of the wire exposed to a short.

[Larry-NC]

Originally Posted by Aussieguy

can't be a steel plate

if it is......... then all of the breakers would not do anything as they would be jumped.
I was thinking it was steel and immediately said to myself that can't work.

Don't be ridiculous! All the breakers have 12 in common on one side (lower side in this image). The individual protected circuits each connect on the terminals on the higher side.

That strip across the bottom is conductive. Whether it's steel, corroded brass, an FR4 circuit card is irrelevant.

[pwoods]

Stryker Guy, I assume your CPAP 12v adapter has a cigarette plug like mine does. My bed was the dinette so I wired in a 12v socket into the light fixture over the sink and screwed the socket into the bottom of the overhead cabinet. I never used the humidifier while camping to minimize draw on the battery. Never had a problem.

[Jamesjfe]

Originally Posted by Stryker Guy

Need to hook a cpap to the DC system. Not directly to the battery. Thoughts?Attachment 287700

Them are thermal reset circuit breakers

[Stryker Guy]

So it worked out that there was a positive right off the battery that I could use as well as the negative to the chassis. I bought an extended DC plug with clips and it gets to the bedside with slack. I had installed a victron shunt monitor earlier. A 1 hour test shows a 4 ah over 1 hour. I have a 120 ah lead acid battery so we are well within limits for an evening. Have a generator and solar to recharge the next day.
Thanks for all the help and input.

[dvalley]

This is what we have should we be in a situation with no electric and it works great. Can get at least two nights on the cpap and it can charge during the day. https://www.amazon.com/iRozce-Genera...ews/B08K38J7S1