Extension cord sizing for inverter to RV plug

[DuneElliot]

So I'm almost done with my battery/off-grid/12v install and just waiting on another paycheck to order the solar panel kit.

I'm hooking my inverter up the quick and dirty way to my RV's current electrical system...an extension cord from the inverter to the RV plug. I can't afford to do anything else right now and it was a suggestion I saw elsewhere. 

The distance is only about 6 ft from the inverter to the RV plug but I also know about voltage drop over distance and thus the need for a larger size cord. I can't find a short (10ft) extension cord in 10/3...the shortest I can find is 25ft. I can find other regular house-size extension cords in 10ft. 

So, my question is, due to voltage drop over distance am I better off using a shorter 10ft cord in small 16 AWG (I think that's the size) or a longer 25ft cord in 10/3 to connect from the inverter to the RV plug?

Of course the best solution would be for someone to point me in the direction of a 10/3 10ft cord!!! (I couldn't find one using my Google-Fu)

 

[John61CT]

110AC doesn't require near as thick wire as low-volt DC.

Depends on the Amps actually used through the cable, but safer to base on the max your inverter will produce.

Issue isn't so much volts dropped as heat buildup.

 

[ArtW]

choose cord by wattage, if all you're running is lights, and a fridge, a light outdoor extension chord is fine, if you want to run AC/microwave, you want that big heavy 10 gauge cord

 

[DuneElliot]

For off-grid it will only be lights, TV and a laptop type stuff. I may, on occasion, use the microwave but maybe only for a minute or two

 

[ArtW]

Standard construction cord should be fine for that, just don't use it to hook to shore power and try to run AC, and yes, shorter cord the better

 

[DuneElliot]

Okay, thanks. I've been running an electric oil-filled heater in the camper off a 100ft extension cord so I guess that should tell me something. I won't be running a heater off the batteries of course.

 

[ArtW]

heaters are rated by wattage, a lot of times, my ceramic heater will run off 700 on low, 1500 on high, I would run it off a regular construction cord on low, but would hesitate to run it on high without the heavier cord
I have run an AC off a regular orange construction cord, but it acted goofy when it kicked on and heated the cord too much at startup, so I got one with 8 gauge
That was in the old junky TT I use for storage now

 

[Weight]

Buy some marine grade tri-plex wire and install your own ends. http://www.genuinedealz.com/marine-wire/flat-triplex-ac-boat-wire?cat=75

 

[Trebor English]

Normal house wiring for 20 amp circuits is 12 gauge.  If your inverter is bigger than 2400 watts you need a bigger cable.  They don't wire houses with 15 amp fuses anymore.  When they did 14 gauge, 15 amp good for an1800 watt inverter.  16 gauge is too small with a microwave and the tv, lights, etc.

 

[highdesertranger]

you could take that 25' cord cut it at 10' and put your own ends on it. that way you end up with a 10' cord and a 15' cord. highdesertranger

 

[jimindenver]

They do make short length heavier extension cords.

 

[Every Road Leads Home]

Here's a ten foot 12/3 cord 15 amps
https://www.grainger.com/product/1X...9877!&ef_id=WD5JEQAABBehLD8a:20170322152601:s

15 foot 10/3 15 amp on ebay
http://www.ebay.com/itm/15-Foot-10-...-3-Wire-10-3-Contractor-Ft-Feet-/172442837434

This company lists they make a 10/3 10' cord on page 9 and another on page 10. Couldnt find anyone carrying them though, a call to them might lead you to the cord.
http://www.mid-statemfg.com/pdfs/midstate_catalog.pdf

I think the easiest way would be to buy the wire at home depot, lowes, or electrical suppy house and put your own ends on. An electrical supply house would probably do it for you.

 

[Weight]

If you buy wire at home depot or like, don't buy the spooled wire, it is too stiff and hard to work. Buy a 10 or 12 AWG extension cord and do like HighDesertRanger said.

 

[Every Road Leads Home]

^ You can get really nice flexible wire off the spool at home depot, least you used to be able too, I had to make a bunch of custom cords for my cabinet shop years ago. Def still get it at a supply house but Home Depot has about 30 spools of wire so I'm sure they still carry it.

 

[Dennis]

I'm carrying a 25' 10/3 and a 25' 12/3 for times I can plug in. Not having an AC to power I believe they will carry anything I need to run including a heater if needed with the 10/3.
During the years when I was in new apartment construction you wouldn't believe what we ran off of 50'-100' 12/3 cords with a four way at the end with 15 amp saws and compressors kicking in at different and same times. Even an electric heater sometimes in the winter. We were at the mercy of electrical contractors that furnished the temporary power poles to the buildings and we used what was there. Biggest problems were when too many trades were trying to use the same pole.

 

[becida]

So I'm almost done with my battery/off-grid/12v install and just waiting on another paycheck to order the solar panel kit.

I'm hooking my inverter up the quick and dirty way to my RV's current electrical system...an extension cord from the inverter to the RV plug. I can't afford to do anything else right now and it was a suggestion I saw elsewhere. 

The distance is only about 6 ft from the inverter to the RV plug but I also know about voltage drop over distance and thus the need for a larger size cord. I can't find a short (10ft) extension cord in 10/3...the shortest I can find is 25ft. I can find other regular house-size extension cords in 10ft. 

So, my question is, due to voltage drop over distance am I better off using a shorter 10ft cord in small 16 AWG (I think that's the size) or a longer 25ft cord in 10/3 to connect from the inverter to the RV plug?

Of course the best solution would be for someone to point me in the direction of a 10/3 10ft cord!!! (I couldn't find one using my Google-Fu)

Interesting thought, hooking the inverter to the RV (120vac) power plug, I'm wondering why? 
All of the RV electrics like lights, water pump, furnace blower & propane fridge (if it requires elect) run off 12vdc.  I guess you could run the TV off the inverter AC...

The AC power for the inverter to the RV plug is going to be fine, AC power travels well.  The DC from the house batteries to the inverter is where you need to watch the wire size & run length, you can find DC voltage drop charts & tables on the internet without too much effort.

My solar runs to the controller then into the battery, the inverter runs off the battery with it's own fused circuit and it's only turned on when needed. When I need 120v AC power I plug a cord into the inverter outlet and use it just for that use. 
When I had a class A I kept a heavy cord plugged in & running over to a standard 6 outlet (surge protected) power outlet, I plugged the whatever into the power strip.

Bob did a blog on using his microwave off his batteries/solar panels, it's really worth finding as the microwave took some serious juice to run!

My thoughts would be less AC dependence & more 12vdc.  In the 12vdc department more & better batteries & as much solar as you can afford & have room for.

 

[DuneElliot]

The inverter and anything needing 110v to run or charge....as mentioned, TV, PS3, laptop and phone/tablet. I also have a couple of free-standing LED lights that I have plugged in. Occasionally the microwave. I realize that my set-up is a little over-kill for most of my power needs, but I'd rather have too much than too little.

 

[Weight]

When considering the size of wire used in a S&B house, the mains electric supply is unending. It becomes hard to see voltage drop in our appliances. From an Inverter electric supply, we are very limited. The batteries can quickly drop in voltage and the 120 will also drop, adding to the overall voltage drop. Get as heavy and as short of an extension cord as you can use for your application. Except for weight, the heavier AWG the better.

 

[SternWake]

Laptops and tablets and phones do not require an inverter. All of these can be powered by an appropriate DC power supply that transforms 12v DC to 5vDC for USB, or to 19.x vDC for laptops. It is also more efficient than using the inverter just to power these items, especially an inverter big enough for a microwave which will use a lot of electricity simply turned on, powering nothing.

For laptop add 'car adapter' to make and model number. make sure it shows a regular looking power brick that has a ciggy plug on it and does not show a simple small inverter which can plug into 12v ciggy receptacle. They run about 25$

For USB charging:
https://www.amazon.com/Blue-Sea-Sys...coding=UTF8&psc=1&refRID=YT4KZZMS3E7F0BS3NJT0

Or plug a product like this into any existing 12v receptacle:

https://www.amazon.com/s/ref=nb_sb_...KIXSG5MO8&rh=n:172282,k:usb+car+charger&ajr=0

 

[highdesertranger]

x2 on what Stern said. also there are plenty of 12v TV's out there today that just sip power. what's a PS2? never mind I looked it up, it is some kind of gaming something or another. it would be kinda of waste to run it off of the same inverter that powers the micro. it might be best to have 2 inverters. you are going to need a pretty big battery bank and a big pure sine wave inverter to run the microwave. highdesertranger