Is conduit cable with 7 strains ok for battery to inverter?

[poot_traveller]

7 Strains meets regulation here in NZ for a campervan.  There is flexible cable and conduit cable and I just want to confirm both are the same type of wire/cable, right?  I know one is flexible and the other isn't, but is there any other difference?

I've got 8 AWG for earth (1 metre) for "grounding" the inverter and battery to the chassis. And + and - cables (2 feet each) for the battery to inverter run.  All 7 strain conduit cable.

This is all good, right?

 

[highdesertranger]

I have no idea as I am not familiar with those terms, 7 strains? flexible cable? conduit cable? do you mean 7 strands? also in mobile application the more flexible the better. but you also need the right type of insulation. here in the USA RV wiring is a joke I don't no about New Zealand. but I use marine wire and connectors, fuse boxes, bus bars, etc. highdesertranger

 

[rokguy]

I think they are referring to 7 strand cabling, ie 7 small flexible wires spiral wound in a cable sheath. Conduit cable is just a plastic tubing the wiring runs in, I thought it can be flexible or straight tubing.
I found this is a good read........http://nzmotorhome.co.nz/forum/viewtopic.php?t=2257

 

[Elbear1]

Multiple small wires does equal one larger. Yes.

 

[poot_traveller]

I have no idea as I am not familiar with those terms, 7 strains? flexible cable? conduit cable? do you mean 7 strands? also in mobile application the more flexible the better. but you also need the right type of insulation. here in the USA RV wiring is a joke I don't no about New Zealand. but I use marine wire and connectors, fuse boxes, bus bars, etc. highdesertranger

Yes I mean 7 strands. Sorry, I sounded it out then tried to spell it (what a fail).

I was more focused on whether the actual thickness of the copper wire is relevant. It is 8 AWG, just that the copper is thicker. In flexible cable I imagine 8 AWG will be 14 or more strands.

 

[poot_traveller]

I think they are referring to 7 strand cabling, ie 7 small flexible wires spiral wound in a cable sheath. Conduit cable is just a plastic tubing the wiring runs in, I thought it can be flexible or straight tubing.
I found this is a good read........http://nzmotorhome.co.nz/forum/viewtopic.php?t=2257

Yes 7 strands.

Thanks for the NZ forum, I didn't know NZ had their own motorhome forum.

 

[poot_traveller]

Multiple small wires does equal one larger. Yes.

I see, so you're saying 8 AWG is 8AWG, regardless of the strand size. Because it does add up to the same amount of copper wire.

 

[Elbear1]

No i wasnt saying that. But yes youre right. Can be hundreds of tiny strands or 3 bigger strands or 1 solid copper strand.

I was saying 8awg + 8awg = 5awg. Using 2 or 3 totally different pieces of wire as a run lowers voltage drop.

 

[B and C]

I would use the flexible cable. The conduit cable is probably stiffer wire (it is here anyway). When you bend a wire back and forth it eventually breaks, right? Think of the vibration in a vehicle bending those wires constantly.

 

[poot_traveller]

No i wasnt saying that. But yes youre right. Can be hundreds of tiny strands or 3 bigger strands or 1 solid copper strand.

I was saying 8awg + 8awg = 5awg. Using 2 or 3 totally different pieces of wire as a run lowers voltage drop.

OK, understood. Thanks

 

[poot_traveller]

I would use the flexible cable. The conduit cable is probably stiffer wire (it is here anyway). When you bend a wire back and forth it eventually breaks, right? Think of the vibration in a vehicle bending those wires constantly.

You've got a good point, and I did think about that. But the + and - cables will be less than two feet, the earth/grounding cables will only be 1 metre, so it shouldn't encounter a lot of vibration, I don't think.

A good example of vibration having no effect on the cable is; the earth/grounding/neutral cable running from the motor battery to the chassis in all vehicles, that gets maximum vibration due to the proximity of the motor and all it's vibrations. And yet it has no effect on the cable.

 

[highdesertranger]

generally speaking more smaller strands is better than fewer strands for a given wire gauge. many smaller strands are usually a lot more flexible so therefore handle vibration better. this is the same reasons solid wire is not allowed for marine applications. highdesertranger

 

[B and C]

The ground cable you are describing has many small wires, not a few big wires. Major difference.

 

[poot_traveller]

generally speaking more smaller strands is better than fewer strands for a given wire gauge. many smaller strands are usually a lot more flexible so therefore handle vibration better. this is the same reasons solid wire is not allowed for marine applications. highdesertranger

An electrical inspector of motorhomes (that I bumped into at an electrical store to day); said that 7 strands is the minimum allowed by regulations for a motorhome (in NZ). That is why I assumed it is okay for a van.

Just doing a quick search on the Internet, it looks like I need a electrical warrant of fitness. That means I need an electrical inspector.

I guess I'm going back to that electrical store on Monday with more questions.

 

[poot_traveller]

The ground cable you are describing has many small wires, not a few big wires. Major difference.

Oh, I see.

 

[rokguy]

I always thought NZ "warrant of fitness" applies only to 240v shore power wiring within a campervan/motorhome and not 12v.
 I have a very good fitout book published the NZ motorhome club.
Might be an idea to see if you can find it in a library or ask them whether you can buy one.

Here in Oz they have some stupid laws regarding 240v wiring in motorhomes, old one I built had it , I planned all the runs,  installed the wiring, double throw power points and employed a local electrician (familiar with RVs) to connect all the bits to get tested.
One I use now only has 12v solar.

 

[highdesertranger]

hey at least you guys have some sort of code to follow. here in the states it's almost anything goes for the wire in an RV. on the 120v AC side manufacturers even use solid residential wire and no one cares. you could never get away with that in a boat. highdesertranger

 

[poot_traveller]

I always thought NZ "warrant of fitness" applies only to 240v shore power wiring within a campervan/motorhome and not 12v.

You're probably right. In fact, I'm certain you are.

 

[rokguy]

Hi mate, I found the book I have from the NZ motorhome association which covers everything on building your own.
Here's the cover and table of contents pages shown below.
It's a very handy book to have.

 

[poot_traveller]

It really does cover an enormous amount of topics.  I'll see if a copy is available online, hopefully I can find one.

Thanks