[kifo4173]

Wondering if someone can direct me/explain the basics of wiring my 110 outlets.

I've completed my DC wiring, including wiring up my 2000 watt MS inverter to DC. However, I've COMPLETELY avoided wiring up my AC outlets.

I only want 3 outlets, spread in different locations around the van. More specific questions below:

1. What wire is standard for 15 amp AC outlets? Is there a specific conduit for AC or will any conduit work?

2. If I want these all to be protected circuits, all wires need to go to my breaker panel right? Aka no junction box? Or do most just have a few outlets on one breaker?


This should be fairly simple I think...I've just never looked at the fine details. Thanks!

 

[proeddie]

15amp 120V circuits are usually wired with #14 AWG wire... In a campervan, I used #12 AWG... stranded is better to allow a little flexing on the bumps.

Depending on what you plan on plugging in, you might just get a circuit breaker extension cord and use that to feed the 3 outlets. The you will need a way to get the shore power from outside to inside the van. There is a grommet behind the back bumper that may come in handy... many have used it. Might also consider getting a GFCI extension cord as an additional safety step.

My link below may give you some ideas.

 

[kifo4173]

15amp 120V circuits are usually wired with #14 AWG wire... In a campervan, I used #12 AWG... stranded is better to allow a little flexing on the bumps.

Depending on what you plan on plugging in, you might just get a circuit breaker extension cord and use that to feed the 3 outlets. The you will need a way to get the shore power from outside to inside the van. There is a grommet behind the back bumper that may come in handy... many have used it. Might also consider getting a GFCI extension cord as an additional safety step.

My link below may give you some ideas.

Thanks. I already have a small breaker box so I just need to figure out how to physically wire to the 3 outlets. I'm reading/researching re: GFCI outlets vs. breakers, and how many outlets to put on each breaker. Your shore power inlet is great! Checked out your website. For now, my van won't have a shore power inlet-no need with my solar/battery configuration, and living in sunny CA.

 

[GaryBIS]

Thanks. I already have a small breaker box so I just need to figure out how to physically wire to the 3 outlets. I'm reading/researching re: GFCI outlets vs. breakers, and how many outlets to put on each breaker. Your shore power inlet is great! Checked out your website. For now, my van won't have a shore power inlet-no need with my solar/battery configuration, and living in sunny CA.

,,


Hi,
GFCIs and Breakers are both good to have, but they protect against different things. The breaker protects the wiring from too much current (amperage) -- when the current exceeds what the wire can handle, the breaker opens and shuts off the current. The GFCI protects people from electrocution -- it monitors the current going out to the load and the current coming back in from the load and if the two differ by even a small amount (which might be you conducting current to ground) it shuts the circuit off.

There are some breakers that include the GFCI function, but most commonly its included in the outlet.

I used #14 Romex sheathed AC wire for my circuits. Its cheap, available, easy to run and the sheathing provides some protection for the wire, so except for places where the wire needs extra protection you don't need conduit. Romex is a bit controversial -- some don't like the fact that it is solid (not stranded), but RV manufacturers use it and in the 4 RVs we have owned (all with Romex) I've not had any trouble.

Another choice is to use something like marine grade stranded wire.
I would not use any kind of wire (eg speaker wire, cheap extension cords) that is not built to a controlled specification -- it is likely just fine, but without the spec you don't know for sure.

You should have a transfer switch that takes you from shore power to onboard power from the inverter, and the switch should also switch the ground wire. When on shore power, the only ground should should be back at the campground power pedistal, but when on inverter, the ground for the AC circuits should be to the RV chassis. An Inverter/Charger takes care of switching the grounds over automatically, but if you have a standalone inverter, you must do the switching.

Gary

 

[kifo4173]

,,

You should have a transfer switch that takes you from shore power to onboard power from the inverter, and the switch should also switch the ground wire. When on shore power, the only ground should should be back at the campground power pedistal, but when on inverter, the ground for the AC circuits should be to the RV chassis. An Inverter/Charger takes care of switching the grounds over automatically, but if you have a standalone inverter, you must do the switching.

Gary

Thanks Gary. Couple follow ups if you don't mind.

It's an inverter charger, so I think I'm good there.

1. Do I need to separate my AC wires from my DC bundle? I think I read somewhere on the forum that it's a good idea for some reason to keep (even insulated) AC wires away from the DC bundle?

2. Not all the outlets need to be GFCI to protect the lot, correct? If my most upstream one is a GFCI, then all downstream outlets are protected if I connect them to the load pair of terminals?

3. Hardware to hook up the physical outlets. Going beyond 'code' if needed, I need the outlet box, the receptacle, and the outlet cover, right? Most outlet boxes are installed in homes it seems on studs, not on the face surface. If I'm building Euro style frameless cabinets, how do I set this up for an outlet correctly? Apologies for the simple question..

Cheers,
Kipp

 

[Zoomyn]

There are* GFCI & Arc Fault circuit breaker combinations, even GFCI/AFCI outlets to place upstream as mentioned that might make utility circuit wiring easier - safer... https://www.lowes.com/search?searchTerm=afci/gfci - with a $10 or $20 premium I'd be using the combination units...

Keeping feeder circuits separated is good housekeeping - in the past folks have had cross-talk of interference, water pump motor singing out of speakers etc. but most electrics have gotten much better - the thing to accomplish is low/no parallel runs, wires in contact with each other over many feet, if the wires have to all go through a bottleneck area that is likely okay if they are not strapped together for the remainder of the distances.

 

[GaryBIS]

Hi Kipp,

I don't think you need to separate AC wiring from DC wiring.

Right on the GFCIs -- you can string several regular outlets off one GFCI and they are all protected.

They do sell surface mount outlets. You might look at the Wiremold stuff and see if that can be adapted. It may be hard to find a GFCI outlet that will work in a surface mount box as they are kind of shallow.

Gary

 

[Hein]

Suggest keeping AC and DC separate (no parallel runs) to keep noise out of your DC side. DO NOT use solid romex wire - it's not safe over the long haul. Solid conductor can work harden and break then arc and cause fire. Many folks are using SO cord for AC wiring. We used heavy 12gauge outside duty extension cord and ran it in smurf tube anywhere it was inside the walls/hidden. Be careful about having back of electrical boxes near outside metal skin of van. You can get condensation inside them due to cold surface being exposed to inside air.

 

[[email protected]]

... DO NOT use solid romex wire - it's not safe over the long haul. Solid conductor can work harden and break then arc and cause fire....

What does work harden mean in this application? Do they flex and then break (such as in a feed to a door)?? Would this apply to AC also? Is just the vibration flex due to open cavities enough to work harden and break?

 

[Santiago]

Suggest keeping AC and DC separate (no parallel runs) to keep noise out of your DC side. DO NOT use solid romex wire - it's not safe over the long haul. Solid conductor can work harden and break then arc and cause fire. Many folks are using SO cord for AC wiring. We used heavy 12gauge outside duty extension cord and ran it in smurf tube anywhere it was inside the walls/hidden. Be careful about having back of electrical boxes near outside metal skin of van. You can get condensation inside them due to cold surface being exposed to inside air.

Good advice Hein,

On banning solid wiring (Romex) in a vehicle (lots of movement unlike a house) I agree. Work hardening changes the copper's grain structure.
To be on the safe side of extraneous DC noise, I will do my best to keep AC and DC apart. Not critical but could avoid potential problems.

Santiago

 

[GaryBIS]

Hi,
I know this Romex or not Romex is an ongoing debate that will likely never end. But just so new readers have the Romex side:

- Romex has been and is still being used in literally millions of commercial RVs. Is it really likely that manufactures of RVs would keep doing this (with all the potential legal problems) if it were a real problem?

- Have looked online for people actually reporting a real problem causing a real failure due to vibration in RVs of Romex wire and have not (as yet) found any. There are millions of them out there, you would think if it was a real problem there would tons of reports?

- Have had 4 RVs over the years that all used Romex and never had even a hint of of a problem.

On the plus side for Romex: readily available and cheap, sheathing provides mechanical protection for the wire, easy to route and install, built to a specification for consistent quality.

My opinion (with no real evidence) is that frequency (very low) and magnitude (very low) of RV vibrations just does not result in problems with solid copper wires. I tried to find lab or field vibration test results or analyses that would shed some actual engineering light on the subject, but no luck so far. The only studies I could find were for much more extreme vibration environments.

My 2 cents Many other alternatives available.

Gary

 

[Santiago]

My opinion (with no real evidence) is that frequency (very low) and magnitude (very low) of RV vibrations just does not result in problems with solid copper wires. I tried to find lab or field vibration test results or analyses that would shed some actual engineering light on the subject, but no luck so far. The only studies I could find were for much more extreme vibration environments.

Thank you Gary. I would add that how its install can make a difference.
I don't think vehicle vibration is the culprit. In my opinion, the culprit is installation, not securing the wiring, too few attachment points.

What I have seen in many factory and one DIY trailer build with looping or dangling Romex wiring with not much support between attachment points.
Due to its weight and vehicle movement you know its in motion and that is not good for the locations it is supported as at that point it is taking the brunt of the movement.

As I said I have seen this even in commercial units wiring AC Romex supply to 120vAC outlets and around breaker box.
If a DIY builder secures all runs I agree with you, vibrations won't be an issue. And yes Romex has great qualities.

 

[Zoomyn]

The no solid-conductor horror stories usually play out in boats; the chop & pounding they experience would have RV's rapidly mechanically disassembled well before the wire fatigues. NO unsupported wire runs, no tree-branch swaying, anchor wiring within 4 to 6 inches of every connection/splice, a hint of nicked conductor while stripping insulation means cutting off before where you damaged it and start over, no nicking bare wire with sharp edged pliers while shaping it for terminals, the list goes on and on. That said - everyone of those practices equally apply to ANY wiring used.

NOTE: "do as I do not as I say" rules likely apply here... My 45-year-old Airstream trailers have happily aged well with their copper romex, however this was revealed only as I tore out everything to rehab one of them in a minimal style ($400 back from scrapyard for 12/120V wire!). Thoughts of 100's of miles of washboard roads ten years from now saw me hustling back to HmDpt to return the solid 10-2 and 12-2 romex bought - and ordering $$$pools of tinned marine grade cable - just because I could... https://www.waytekwire.com/products/1461/Marine-Wire-Cable/&-of-Conductors=3 ...wiring to be also used in the 1973 27-foot Airstream project trailer. IIRC it was not a huge increase in price to do it right.

 

[pmgia]

The Recreation Vehicle Industry Association has Standards for the RV manufacturers related to electrical and almost every other subcategory. I choose to follow these standards even at additional cost. It saves life, prevents fires or other systems onboard from being faulty. Most importantly, it helps resale.

 

[cahaak]

Strain hardening in metals only occurs with frequent deformation that is beyond the elastic limit for the metal. That type of deformation is not going to occur in any type of a quality installation in a camper van. The main drawback to solid conductors is that they are more difficult to bend than stranded conductors and those types of bends are sometimes necessary for vehicle installations. For limited bend applications, solid conductors don't pose any issues when properly installed in a vehicle.

 

[Sayn3ver]

I'd rather use mc cable with stranded conductors. Crimp on your fork or ring terminals, heat them and connect your devices... assuming you can get metal boxes in the flavor you need.

You can also purchase plug in outlets like some commercial jobs have been using. They provide a wiring harness with the appropriate connector that is spliced onto your field wiring. Then the device can just be plugged in on the back and installed. These are designed for making it safer for maintenance personel. They might be beneficial in this application but they are more expensive and are not readily available.

Regardless which way you go just know a loose connection is a hot connection when loaded, which creates more resistance, than more heat until a fire breaks out. Joule loading is the term I believe. Mechanical connections tend to come lose over time, even without vehicle vibration. Many large facilities will have maintenance done on their switch gear, large disconnects, transformers, panels, etc where a contractor will be hired to come in and check and retorque connections. This is especially important with aluminum conductors. Thermal expansion and contraction alone during loading of the circuit can cause mechanical splices and terminations to loosen over time.

Just something to think about.