110V AC & 12V DC layout plans

If you're starting from scratch to build the 30A inlet, you might want to consider the SmartPlug system, rather than the traditional Marinco-style inlet connection.

Hi evy,

No, but some campsites have worn out 30 amp. When that happens I use my 50 to 30 dog bone adapter. Make sure any adapters you purchase are the dog bone type.

I caused to have a "break out" box made so I can extract a 30 amp on one leg and two 20 amp circuits on the other. Each outlet has it's own circuit breaker. I use this in the winter time to allow me to heat my RV 100% on electric.

evy wrote:
Also, do I really need a 50amp to 30amp adapter? or is this adapter for owners of 50amp inlet RVs??

evy wrote:
Also, do I really need a 50amp to 30amp adapter? or is this adapter for owners of 50amp inlet RVs??

No

Very rare to encounter a 50a site without also having 30a available.
Get the adapter only if needed.

Also, do I really need a 50amp to 30amp adapter? or is this adapter for owners of 50amp inlet RVs??

DrewE wrote:
Some RV extension cord ends might not fit into the recess around the prongs, so you might have to use some care in selecting them

Now how did you know this was going to happen?!

The extension end is not long enough and wont go all the way in :(

No problem I will simply sell it and buy another one, I guess that's what happens when buying things online.

DrewE wrote:
50A service would be entirely overkill for this van IMHO, and likely most class B's. It would also require a different electrical panel.

If you wire the inverter to the main breaker box, you need some sort of a transfer switch, since you now have two sources to feed one system. It's no different than a generator so far as wiring needs are concerned, just powered by 12V batteries rather than gasoline. Some inverters have transfer switches built in (and these typically would be wired to one or two individual branch circuits). If you plug a shore power cord into the inverter, then you don't have more than one supply connected to your system and you don't need a separate transfer switch; in effect, your moving the cable around is the transfer switch.

That 30A inlet looks okay to me. Some RV extension cord ends might not fit into the recess around the prongs, so you might have to use some care in selecting them (or the sockets you select to put on the end of a cord you assemble). It is hard to tell from the picture whether it's sturdy and well-sealed and well-made, or cheap junk. It seems obvious to me that this is one place where cheap junk should be categorically avoided.

I will take pictures of the inlet when I receive it, and post them here because I have no idea what is considered junk.

So if I understand, I have two options :

option 1 (switch box) : I always use the same AC outlets in my campervan, they could be powered by shore power, the generator or the inverter, the switch box will decide where the AC power is coming from.

option 2 (no switch box) : when I have shore power the AC outlets installed in my campervan work, when the AC is coming from the inverter I have to connect my stuff into the inverter's outlets, when the AC is coming from the generator I have to connect my stuff into the generator's outlets.

So I would have more work and expenses wiring everything to a switch box but it would be less complicated because I would always be using the same AC plugs right?
Am I missing anything?

50A service would be entirely overkill for this van IMHO, and likely most class B's. It would also require a different electrical panel.

If you wire the inverter to the main breaker box, you need some sort of a transfer switch, since you now have two sources to feed one system. It's no different than a generator so far as wiring needs are concerned, just powered by 12V batteries rather than gasoline. Some inverters have transfer switches built in (and these typically would be wired to one or two individual branch circuits). If you plug a shore power cord into the inverter, then you don't have more than one supply connected to your system and you don't need a separate transfer switch; in effect, your moving the cable around is the transfer switch.

That 30A inlet looks okay to me. Some RV extension cord ends might not fit into the recess around the prongs, so you might have to use some care in selecting them (or the sockets you select to put on the end of a cord you assemble). It is hard to tell from the picture whether it's sturdy and well-sealed and well-made, or cheap junk. It seems obvious to me that this is one place where cheap junk should be categorically avoided.

I agree with everyone on the use of adapters over the use of 30 and 20 amp feeds. While we are on the topic of adapting - have you considered using 50 amp service. It would probably be overkill, but are you aware that 50 amp service is 220 volts and gives you two 50 amp-110 volt legs while 30 amp service gives you just 1 30 amp leg? I have 50 amp service and use doggone adapters to step down to 30 or 20 amp service as required. I like it because it's a flexible approach.

Dog bone adapters are less likely to 'heat' than the 15 amp to 30 amp adapter shown.



I cut my cord and added a male end. I'm glad I did that as I've replaced it twice so far.

DrewE wrote:
Basically, you need a transfer switch whenever there are or could be more than one 120V AC supplies that are wired to power a single circuit. Plugging the shore power cord into the generator is one good way of eliminating the need for a separate transfer switch (and the system that TakingThe5th described is basically the same thing).

I note that you show both a 30A and a 15A power inlet. You would need some sort of a transfer switch there if you have both, since plugging in one would otherwise energize the other. That could lead to all sorts of evil things. (If, for example, you have a generator connected to the 15A connection when you plug in the 30A one, you have the generator energized...or, if the power is out, you backfeed the electrical grid. Also, you could end up with exposed energized male plugs, ready to shock the unsuspecting.) I would only have the 30A inlet and use an adapter when needed.

Quick couple of questions,

Is this ok for my 30A inlet hatch? I would buy it on amazon.


As for the 15A inlet, I thought I would use it when I'm hooked up to a house, on a regular outside 15A outlet, I didn't know I could simply add an adapter at the end of my regular 30A extension.
And this is what it looks like? I guess it's for horizontal 15A outlets? (like I have on my house) I would also buy this on amazon.


Can you connect the inverter to the 110V AC panel? If so would I need a transfer switch?

Maybe I could install an extension hardwired to the transfer switch, and I hook it up to the generator in my rear outside box?