12v wiring

Melbo · July 13, 2006, 06:43:55 PM

I don't remember where it came from but I know you are not supposed to run low voltage in a conduit with 120 volt wires. Maybe a city inspector tagged me for that when we had a sprinkler control wire running in a conduit with the outside yard lites but I know you are supposed to keep em separate. If the 120 is in metal you can use plastic for the low voltage or vice versa but you can't run them both in plastic parallel next to each other. Also watch your cross section fill ratios and conductor count in each conduit. I always seem to want to add something and don't have a large enough conduit ( to dissipate heat ) or already have too many conductors in the conduit ( neutrals don't count ). Just my thoughts.

Melbo

travelingfools · July 25, 2006, 11:22:12 AM

Hi all..new here and new to the building process...I understand that it is correct to use stranded wire instead of romex in conversions, I was just wondering the reasons for this...

So much to learn...

FloridaCliff · July 25, 2006, 12:52:22 PM

Stranded is way more tolerent to the flexing that will take place in a moving vehicle.

Stranded is standard in planes, boats, cars and trucks.

Many have reported using romex and securing it well with no problems.

I'm just one of those guys that doesn't like to push my luck, so I used THHN or SOOJ.

Cliff

pvcces · July 25, 2006, 08:56:53 PM

Besides, it's very easy to make a good crimp connection with stranded wire, but not so with solid.

For what it's worth.

Tom Caffrey
Suncatcher
Ketchikan, Alaska

jraynor · August 25, 2018, 09:13:14 AM

Not to bring up and old subject but this post has some good info in it for 12v wiring. I have come across some 18/2 stranded cable for general purpose. Basically I plan to use it for lighting since it is 2 wire in a sheathing. According to American wire gauge it can carry 16 amps for chassis wiring which at 12 Volts would be 192 watts. I plan to use LED lights and found that simple puck lights run 2 watts.

Just wanting some other opinions, but does this 18/2 wire seem good for the job?

https://www.powerstream.com/Wire_Size.htm

gumpy · August 25, 2018, 09:47:59 AM

Seems like it would work well if all you're using it for is LED lighting. Anything else and you would need to reevaluate the current draw, but it sounds like you got that in hand already.

Fred Mc · August 25, 2018, 09:52:51 AM

One of the things I discovered in doing research for my solar panel wiring is how IMPORTANT size is for 12v wiring. Obviously LED's let you get by with smaller sizes but for bigger draws it appears as though size is VERY important to prevent too much resistance.

Jim Blackwood · August 25, 2018, 10:33:21 AM

Are any of you guys using wire with cross-linked polyethelyne insulation? I think the designations are TXL, GXL and SXL for the different insulation thicknesses. This is the stuff the automotive OEM's have been using for the last few decades now, not sure about the busses. Really great insulation, far superior to vinyl, including THHN which is basically just vinyl insulation with two layers, and the clear layer rapidly decays and splits off as I'm sure you have seen.

I refuse to use anything else for road-going applications. It does cost a little more but it's nothing for what you get. It's durable and tough, doesn't crack or fall off and is more resistant to heat. Much slower to dry out and get hard, probably by a factor of at least 10:1. That's what I use for all my DC wiring, and I go online to order it, usually in spools from 50' on up but shorter lengths are available in the heavier stuff. I use the thin insulation and light gages for the signal wires and the thick insulation and heavier gage for current carrying wires. I find it often makes more sense to run a single large cable, install relays near the loads and then run light signal wires to switch the relays.

I also almost exclusively use adhesive lined heat shrink terminators at the wire ends and sealed connectors (Deutch is a good brand) to keep the oxygen in the air away from the conductors. No O-2 means no corrosion which means reliability. Also a good dielectric grease on any exposed connectors. There are several brands such as CU-AL, NO-OX, etc. and fully coating each piece after cleaning is a good idea.

Now on the AC stuff, if you put it in conduit there are a lot of choices but I think I'd still go down to the local electric supply house and ask them if cross-linked is suitable for AC conduit installation. It really is that good, and I'd be comfortable with using it for A/C. It is overkill compared to a lot of what is out there but much safer.

Jim

eagle19952 · August 25, 2018, 02:26:10 PM

Quote from: Jim Blackwood on August 25, 2018, 10:33:21 AM
Are any of you guys using wire with cross-linked polyethelyne insulation? I think the designations are TXL, GXL and SXL for the different insulation thicknesses. This is the stuff the automotive OEM's have been using for the last few decades now, not sure about the busses. Really great insulation, far superior to vinyl, including THHN which is basically just vinyl insulation with two layers, and the clear layer rapidly decays and splits off as I'm sure you have seen.

I refuse to use anything else for road-going applications. It does cost a little more but it's nothing for what you get. It's durable and tough, doesn't crack or fall off and is more resistant to heat. Much slower to dry out and get hard, probably by a factor of at least 10:1. That's what I use for all my DC wiring, and I go online to order it, usually in spools from 50' on up but shorter lengths are available in the heavier stuff. I use the thin insulation and light gages for the signal wires and the thick insulation and heavier gage for current carrying wires. I find it often makes more sense to run a single large cable, install relays near the loads and then run light signal wires to switch the relays.

I also almost exclusively use adhesive lined heat shrink terminators at the wire ends and sealed connectors (Deutch is a good brand) to keep the oxygen in the air away from the conductors. No O-2 means no corrosion which means reliability. Also a good dielectric grease on any exposed connectors. There are several brands such as CU-AL, NO-OX, etc. and fully coating each piece after cleaning is a good idea.

Now on the AC stuff, if you put it in conduit there are a lot of choices but I think I'd still go down to the local electric supply house and ask them if cross-linked is suitable for AC conduit installation. It really is that good, and I'd be comfortable with using it for A/C. It is overkill compared to a lot of what is out there but much safer.

Jim

good stuff

gg04 · August 25, 2018, 06:29:06 PM

I still use noalox and heat shrink for 6ga. And down, but use Jet-lube and cold shrink for 4ga. and larger..makes battery banks on boats last longer, really stops corrosion..makes much better seals..rdw

windtrader · August 25, 2018, 09:26:36 PM

Would spray type anti-oxidant get into bare wire better than the grease? Often there is some bare wire where the clamp is attached. Just wondering if the grease might not protect as well. Spray application might be easier to get into tight places.

Jim Blackwood · August 25, 2018, 09:38:32 PM

Main thing is to get it into the interface between the two parts. I feel like the grease provides a better film to keep the air out. A spray would be better than nothing but I don't think it could possibly be as durable. OTOH if you are trying to wick it back up the wire it would probably do that better.

Jim