Wiring Diagram Review Please?

[sean882]

Hi, I picked up a project last month. I'm starting to plan out the electric. My approach is to wire it once for anything I might decide to add in the future. I plan on using it to work remotely out of (occasionally), and have decided I would like...

-Charge battery from Shore Power
-Maintenance charge from 7-pin on tow vehicle
-12V from battery
-120V from shore power (30A)
-120V from inverter

I don't plan to integrate solar at any point in the foreseeable future.

Would you mind having a look over the attached wiring diagram and offering suggestions, safety issues, etc? Please disregard the reference to the suicide cord - I've already been talked out of this and will use a powerstrip instead.

I've intentionally left trailer light wiring off this diagram - I'll be running that on a completely independent circuit per normal installation.

Thanks!

[saltydawg]

It looks good but my suggested changes.

everything down stream from the 20 amp breakers 12 gauge is fine, its rated for 20 amps so save money and energy fighting the 10 gauge, go with 12.

honestly 30 amps coming is is way over kill unless your gonna have a 110 volt 10k btu AC. I would go with 20 amps, use 12 gauge to the panels, then do 15 amp breakers and use 14 gauge to all the out lets.

Next dont do a suicide cord. put a transfer switch fed from the inverter between breaker 2 and the plugs it powers. A double throw double pole switch is cheap enough and just label it shore and inverter. Then put a little 120 volt led light next to the switch. this does two things one shows you where power is available, two a reminder to shut the inverter off.

That is my basic plan. I am also mounting a 120 v fan that will be tied to the common pole on the switch to vent the area where my inverter and charger will be. So if the shore power or the inverter is on the fan will run. Both the inverter and charger putout heat so I want to fan force some fresh air for them.

fan
https://www.amazon.com/gp/product/B009O ... 16S5&psc=1

the transfer switch I plan to use. I dont think the built in lights will work on 120 but its rated to 18 amps at 120
https://www.amazon.com/gp/product/B001P ... UTF8&psc=1

[troubleScottie]

Fine start.

Not sure about the suicide connector. Most likely if you lack shore power ( generator or shore power), you will not want to run your 120AC appliances. The power draw plus the inefficiencies of the inverter would consume your battery.

You need a switch to disconnect the inverter when it is not in use. They draw power even when not powering a device. A fuse would be good too.

Your 200A Fuse for your DC circuits is a bit large.

Also, the 7pin connector's 12V will most likely not be sufficient to charge the battery. The 7 pin wires are often very small. You would be better off running a separate wire set with a solenoid to isolate your towing vehicle battery from the trailer battery and appropriate fuses plus some sort of DC-to-DC MPPT device. The wire should be reflect the expected charging amperage. Think like a powerful stereo. Often DC-to-DC charger have two sources, so you could wire in solar later. Also the DC-to-DC device will provide more controlled charging.

You might want to have separate wires for each device connected to the switch panel unless the switch panel has fuses in it too.

you might want switches in the wall near the door, so you can turn on the cabin lights without crawling in. You might want additional USB connections. Also a couple of 12VDC sockets might be useful.

Also, there is little need to ground your AC or DC to the frame. One, you are using specific returns. Two, if your frame is screwed together, the ground might not work.

[saltydawg]

A fuse would be good too.

Your 200A Fuse for your DC circuits is a bit large.

I though 200 was huge until I saw the size if his inverter, then it makes sense. His 200 am fuse is sized mostly for the inverter I think. I do think he is missing a fuse for the 10 gause to the small fuse block.

I will have a 100 amp fuse that feeds my inverter and another fuse block with a 40 to the house 12v panel.

[tony.latham]

I'm just wondering what you'll be running with that big inverter?

Just curious.

Tony

[sean882]

A fuse would be good too.

Your 200A Fuse for your DC circuits is a bit large.

I though 200 was huge until I saw the size if his inverter, then it makes sense. His 200 am fuse is sized mostly for the inverter I think. I do think he is missing a fuse for the 10 gause to the small fuse block.

I will have a 100 amp fuse that feeds my inverter and another fuse block with a 40 to the house 12v panel.

Good call on the missing fuse. My thought process was that I'd draw from one of the 12 fused circuits to power the switch panel - but I didn't indicate that in the drawing. I'll make a note of that to be sure I don't bypass it.

My thought on sizing the 200A fuse was to fuse for the wire being used rather than for the load, and to select wire that would allow the inverter to be used to its full peak rating. I have no devices that would draw nearly that much power now, but the inverter itself was a freebie. If a significant other ever decided a microwave was a necessity or something, I figured it'd be better to be pre-wired for it's potential than not.

[sean882]

Fine start.

Not sure about the suicide connector. Most likely if you lack shore power ( generator or shore power), you will not want to run your 120AC appliances. The power draw plus the inefficiencies of the inverter would consume your battery.

You need a switch to disconnect the inverter when it is not in use. They draw power even when not powering a device. A fuse would be good too.

Your 200A Fuse for your DC circuits is a bit large.

Also, the 7pin connector's 12V will most likely not be sufficient to charge the battery. The 7 pin wires are often very small. You would be better off running a separate wire set with a solenoid to isolate your towing vehicle battery from the trailer battery and appropriate fuses plus some sort of DC-to-DC MPPT device. The wire should be reflect the expected charging amperage. Think like a powerful stereo. Often DC-to-DC charger have two sources, so you could wire in solar later. Also the DC-to-DC device will provide more controlled charging.

You might want to have separate wires for each device connected to the switch panel unless the switch panel has fuses in it too.

you might want switches in the wall near the door, so you can turn on the cabin lights without crawling in. You might want additional USB connections. Also a couple of 12VDC sockets might be useful.

Also, there is little need to ground your AC or DC to the frame. One, you are using specific returns. Two, if your frame is screwed together, the ground might not work.

Thanks, I'll definitely take your and Saltydawg's advice and get a transfer switch in there.

My thought for running 120VAC appliances off of the battery comes from working remotely. I'm lucky enough to be able to work remote for the foreseeable future, but not lucky enough to be free of work It'll likely just be a laptop charger, computer monitor, and an external hard drive or two. Nothing substantial, but a few plugs all the same.

Alright, maybe I'll hold off using the vehicle to charge the battery for the time being. I know my 7 pin wire is fused at 30A, but I like the idea of dedicated wiring and an mppt to optimize the charge more than just a maintenance top-off.

I like your idea of adding an extra switch and some spare USB plugs too. Can't have too many of those!

[troubleScottie]

To the ideas on the laptop, monitor and external hard drive.

You should be able to have direct 12VDC connection to charge your laptop and to run your monitor. Laptop often need about 15VDC. That means an adapter to convert 12VDC to 15VDC. Check with the vendor of the laptop. Most external hard drives could be run via the USB connector to the laptop. (at least the 3 I own) The battery in the trailer will deliver much cleaner power than the power from the inverter or possibly a generator.

Also it is not particularly efficient to convert 12VDC to 120VAC then back down to 12-15VDC via the computer power cords. Inverters often have a 20-40% loss. That is part of the reason for a high price in some inverters. This applies to the monitor as well. PS: make sure if you use the inverter, it should be a good sine wave inverter. Electronics does not like a chopped wave.

Although I should know if monitors have a direct 12VDC connection, I do not know for sure. I know there are several LED TV that have direct 12VDC connection. Again check with the vendor of the monitor. There should be a 12VDC solution.

[H.A.]

1, You should add a disconnect means to the ”charger/converter”. As drawn, it will recieve 120V input when the inverter is running.
2, As mentioned, 10AWG is absurdly large for any wiring behind your 120V main breaker/disconnect.

[saltydawg]

1, You should add a disconnect means to the ”charger/converter”. As drawn, it will recieve 120V input when the inverter is running.

No he has it drawn to only feed the one circuit, he said the breaker would be off when he was using the suicide cord. By using a transfer switch he would make sure it would not feed the circuit that has the charger on it.

[H.A.]

1, You should add a disconnect means to the ”charger/converter”. As drawn, it will recieve 120V input when the inverter is running.

No he has it drawn to only feed the one circuit, he said the breaker would be off when he was using the suicide cord. By using a transfer switch he would make sure it would not feed the circuit that has the charger on it.

He said breaker #1 would be open. Backfeeding with ’suicide cord’ as shown on drawning will energise all 120V circuits on breakers #2 & 3 including that Progressive converter charger thing.
Of course, somewhat a moot point as its claimed suicide cord wont now be used, but even with a proper transfer switch still important that converter thing is not energised when inverter is running.

[saltydawg]

He said breaker #1 would be open. Backfeeding with ’suicide cord’ as shown on drawning will energise all 120V circuits on breakers #2 & 3 including that Progressive converter charger thing.
Of course, somewhat a moot point as its claimed suicide cord wont now be used, but even with a proper transfer switch still important that converter thing is not energised when inverter is running.

Your right I was thinking breaker two.