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Discussion Starter #1
Hey guys,

Hope everyone is is happy and healthy in these crazy times

Right I'm about to do my wiring this week and just checking on a few AC wiring questions.

So I'm going to have a 15amp shore power connection , a 1000w renogy inverter/charger , and probably 3 outlets in the van . Would I be ok to use 14awg Romex wire throughout my install as I will not be running anything high power.....just laptop charging and that sort of thing .

So 15amp shore power going to main breaker 15amp , then onto inverter input , out of inverter to another 15amp breaker, then out from breaker to my 3 outlets . All using 14awg wire, does that sound correct

The manual says use 10-6awg Ac wire but that seems overkill?

Thanks

Lewis
 

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We used Romex in wiring the 120 volt AC in our van although many on this Site do not like the use of solid wire. They argue that solid wire can 'fatigue' and break due to vibration. We dismissed those concerns as unlikely and used solid Romex.

It is not what 'low power' 120 volt loads you expect to connect that determines wire size; rather, what circuit breaker size you use. It is assumed that someone might plug something higher power in, sometime, so you need to be 'wired' for a full 15 amperes. 14 gauge wire is adequate for 15 amp 120 volt circuits.

It's the 12 volt side of your inverter/charger that requires the larger gauge wire - - an inverter supplying 1000 watts, with known efficiencies, can draw upwards of 100 amperes (DC).
 

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Discussion Starter #3
We used Romex in wiring the 120 volt AC in our van although many on this Site do not like the use of solid wire. They argue that solid wire can 'fatigue' and break due to vibration. We dismissed those concerns as unlikely and used solid Romex.

It is not what 'low power' 120 volt loads you expect to connect that determines wire size; rather, what circuit breaker size you use. It is assumed that someone might plug something higher power in, sometime, so you need to be 'wired' for a full 15 amperes. 14 gauge wire is adequate for 15 amp 120 volt circuits.

It's the 12 volt side of your inverter/charger that requires the larger gauge wire - - an inverter supplying 1000 watts, with known efficiencies, can draw upwards of 100 amperes (DC).
Thanks Winston

I have 2awg wire DC side with 150amp DC fuse so that will handle the amp draw I need on the DC side.

I was just concerned that what the manual says for Ac input to use 10-6 awg AC WIRE .

cheers

Lewia
 

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Hey guys,

Hope everyone is is happy and healthy in these crazy times

Right I'm about to do my wiring this week and just checking on a few AC wiring questions.

So I'm going to have a 15amp shore power connection , a 1000w renogy inverter/charger , and probably 3 outlets in the van . Would I be ok to use 14awg Romex wire throughout my install as I will not be running anything high power.....just laptop charging and that sort of thing .

So 15amp shore power going to main breaker 15amp , then onto inverter input , out of inverter to another 15amp breaker, then out from breaker to my 3 outlets . All using 14awg wire, does that sound correct

The manual says use 10-6awg Ac wire but that seems overkill?

Thanks

Lewis
I am not sure what you mean by thoughout. 14 gauge is ok for the AC side as the max current would be based on 1000watts, less than 10 amps. I don't like the idea of romex but it will probably be fine. 10-6 is overkill on the AC side.

On the DC side 14 gauge will be totally insufficient. To get 1000 watts out of the inverter you will pull over 80 amps from the battery. Nothing less than 4 gauge in my book. I'd use 1/0 but 2 gauge is ok.

Just because something is ok doesn't make it optimal. It really just depends on your design philosophy, if you are trying to get by with the minimum then 14 gauge romex on the AC side is not dangerous. I went the other way and went with overkill, because there is a voltage drop across wiring and a smaller voltage drop on larger wires. I used much larger wiring than really even needed at the expense of a little weight and some money, but it is friendlier on my systems and I lose less power in my wiring. I optimized and oversized pretty much everything in my electrical system
and the one area I didn't, I came to regret while I was rushed into fixing at an inopportune time (luckily it just cost me some money and a sunburn in a parking lot in the middle of Connecticut)

Do not use the romex on the DC side! Use it on the AC side if you want.
 

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Thanks Winston

I have 2awg wire DC side with 150amp DC fuse so that will handle the amp draw I need on the DC side.

I was just concerned that what the manual says for Ac input to use 10-6 awg AC WIRE .

cheers

Lewia
I saw this after starting writing my reply. I am glad you weren't going to use 14guage on the DC side!

I will add that if you are just charging, it will be more efficient to use DC chargers and only turn on the inverter when really needed.

I save myself about 15 amp hours a night when I got a DC power converter for my breathing machine so I didn't need the inverter running all night. I have a 3000 watt Victron inverter and it uses about 1-2 amps just being on and about 1 amp more than the DC power converter when running the breathing machine.
 

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Discussion Starter #6
I am not sure what you mean by thoughout. 14 gauge is ok for the AC side as the max current would be based on 1000watts, less than 10 amps. I don't like the idea of romex but it will probably be fine. 10-6 is overkill on the AC side.

On the DC side 14 gauge will be totally insufficient. To get 1000 watts out of the inverter you will pull over 80 amps from the battery. Nothing less than 4 gauge in my book. I'd use 1/0 but 2 gauge is ok.

Just because something is ok doesn't make it optimal. It really just depends on your design philosophy, if you are trying to get by with the minimum then 14 gauge romex on the AC side is not dangerous. I went the other way and went with overkill, because there is a voltage drop across wiring and a smaller voltage drop on larger wires. I used much larger wiring than really even needed at the expense of a little weight and some money, but it is friendlier on my systems and I lose less power in my wiring. I optimized and oversized pretty much everything in my electrical system
and the one area I didn't, I came to regret while I was rushed into fixing at an inopportune time (luckily it just cost me some money and a sunburn in a parking lot in the middle of Connecticut)

Do not use the romex on the DC side! Use it on the AC side if you want.
Thanks for input.

It's meant to read throughout. I'm using 2awg on DC side so I believe that is ample .

I am only using Romex on Ac side , all DC wiring is stranded

Cheers
 

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Thanks for input.

It's meant to read throughout. I'm using 2awg on DC side so I believe that is ample .

I am only using Romex on Ac side , all DC wiring is stranded

Cheers
Nothing dangerous about that. I don't think the solid wire is as likely to break as people think. I would take extra care to secure it, but as long as it is not flapping around the risk is probably overblown. Romex is pretty easy to work with also.

I used to work as an electrician in a prior career and the ease of use of solid wire is nice! No crimping is nice. I bet I made 30-40 crimps today rerouting wire in my van and adding a few outlets.
 

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...Just because something is ok doesn't make it optimal. It really just depends on your design philosophy, if you are trying to get by with the minimum then 14 gauge romex on the AC side is not dangerous...
I don't see 14 gauge as "minimal" for the AC side. As long as it's fused at 15A max, that's what's used in every house in the country (hopefully). The runs in a van aren't anywhere long as some of the runs from one end of a house to the other, and the AC voltage drop at 120V is minimal... not enough to make a difference.

I don't think that the OP has to feel like he's "just squeaking by" with 14AWG.

I prefer stranded wire in my van, but I've seen lots of commercial RVIA-approved RV's wired with Romex.
 

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Vibration won't hurt solid wire.
Stranded is not used for vibration protection. It's used for pulling through conduit because it flexes.
I personally hate terminating stranded, but sometimes you have to use it.
Solid wire is used so it doesn't pinch/compress when stapled to a wood. That's it. Stranded for flexibility in conduit and solid for no pinch points/hot spots.
Vibration is not a factor.
There have been times that I have soldered the ends of stranded wire before tightening down on a receptacle, when I was worried about vibration. Never had a solid come loose. I've fixed other people's loose wires and they almost always curl the wire counter clockwise.
I always curl the wire around the screw clockwise, so it closes tighter around the screw as you tighten.
Anyway, unusually run 14 for lighting circuits and 12 for appliances and high use receptacle circuits. 12 is rated for 25amps and 14 to I think 15 or 20, I'd have to look.
Anyway, 14 will handle short 120v, 15 amp runs, no problem.
The more important concerns are don't kink or pinch stranded and your terminations on both need to be clean and tight.
 

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There have been times that I have soldered the ends of stranded wire before tightening down on a receptacle, when I was worried about vibration. Never had a solid come loose. I've fixed other people's loose wires and they almost always curl the wire counter clockwise.
I always curl the wire around the screw clockwise, so it closes tighter around the screw as you tighten.
Yep, I often solder the end of stranded wire so it attaches under a screw (in a clockwise direction) more securely.
 

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I freaked out when the hack electrician that our home builder hired,....ran 12/2 for the AC condenser outside.
It's 230v. He used black and white as the hot legs and the ground as neutral. Granted, it's a small, efficient unit and draws roughly 13 amps, but it was one of many (100s) reasons I fired the builder.
"Technically", it will work and the 12/2 can handle 25 amps if it had to, but that's not the point.
It should have been 10/3.
My point was that a friend of mine who's a foreman for an electrical company and knows all the codes, said 12/2 can "handle" 25 amps, even I they rate it lower. But it's always good to go by the rating and give yourself a buffer. And he agreed that the condenser would work and the 12/2 would handle the 13amp draw, but he would have installed 10/3 if it were him.
So, 14 is rated at 15 amps and can probably "handle" 20.
I guess my point to all this rambling is just to confirm that 14 for a few short runs off an inverter should be fine.
 

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Hi,
The wire current ratings depend on the application. For home wiring, the 15 amps for #14 is used, and is conservative -- probably because home wiring often goes through insulation.

I think that the ratings that the American Boating and Yachting Council (ABYC) provides for marine applications are closer to RV applications than home wiring standards.
The ABYC ratings for #14 go from 15 amps up to 35 amps depending on the temperature rating of the wire insulation, but for wire with insulation rated at 90C (which is quite common), its 30 amps except in engine rooms, where its 25 amps.

Here is the table: http://assets.bluesea.com/files/resources/reference/21731.pdf

The BlueSea Circuit wizard uses the ABYC ratings and also takes into account voltage drop -- so, it seems like a good way to go. The ABYC ratings are for AC or DC.

Gary
 

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A big complaint in RVs is how unreliable the electrical systems are. One of the reasons that they are so unreliable is the use of solid wire. Even the RV industry is starting to go stranded in more and more places.

Romex is intended for use in relatively constant temperatures and stationary use (like a home)

Stranded wire is designed for use where there is vibration, large temperature swings. (boats, cars) or other running very large wires through conduit.

You won't find solid core wire in a car or a boat, because it will fail in use. Even the bean counters in the auto industry realize this and pay the extra cost for stranded.

A MUCH better wire choice for use in a van is SJOOW wire. Here is a link to Lowes but home depot also carries it:


An easy way to connect stranded wire to an outlet is to crimp on a fork terminal. They are available on line or at most auto parts stores. Dramatic improvement in reliability and safety vs romex.
 

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I wouldn't run an entire vehicle electrical system in solid wire.
We're just talking about a few short runs to receptacles from an inverter.
What are the effects of temp on solid over stranded, that would be detrimental to a few short runs to receptacles from an inverter?
I'm not recommending solid is preferred for superior. Just looking to hear what the harm is in this particular application.
 

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I hear you Harry, but I don't buy it.

I've had 4 RVs all wired with Romex and never had a solid wire failure -- a couple of them had quite high mileage with lots of rough roads.

Many (most?) commercial RVs are wired with Romex -- I just don't see them taking the legal risk of doing this if there was any real problem.

The low freq vibrations you get driving an RV over roads just don't seem to me to be the kind of vibration environment that would cause wire failure.

I spent some time searching for actual reported instances where people reported real failures of solid wired in RVs -- I could not find any.

I could be wrong, but just don't see it as a real issue. I'd like to see some hard evidence.

Gary
 

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Discussion Starter #18
Thanks guys for all your responses

This is quite the hot topic on solid wire over stranded.

I'm asking my electrician friend so I'll report back on what he says

Cheers

Lewis
 

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The temperature range question is more related to the insulation type, not the copper itself. If you look at wire supplier web sites, you can buy wire with the same strand count but with various insulations that resist temperatures down to only ~ 20 F (some marine wires) or down to Mars cold conditions. It is really the low temperature end of insulation that is a factor in a vehicle, assuming that your chosen wire size is correct. As a reference, automotive parts are rated for use down to ~ (-40 F)

You can do a quick and dirty test of vibration resistance in 2 minutes in your own hands.

Take a 6 inch piece of 12 awg wire (solid) and hold it with a pliers in each hand. Start bending it back and forth and see how long it lasts. Do the same thing with stranded wire that I suggested and see what you think. The test will cost you about $1 in parts.
 

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Not sure if that would represent the vibrations a 14/2 wire would experience, running from a breaker panel to a receptacle. Even in a van.
That's something a wire would experience if it has to bend with the opening/closing of a door. And no one would run solid wire in a door.
And since ambient will probably never get hot enough to melt the insulation and since the wire will not be flexing, it will never be cold enough to crack.
Just not seeing the concern for the OP's application.
If it is getting that hot, cold or vibrating violently enough to snap 14ga copper in the van, the wire is the least of the concerns.
 
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