Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Caflashbob on October 27, 2018, 01:44:20 pm
Title: Wiring differences
Post by: Caflashbob on October 27, 2018, 01:44:20 pm
Recently I renewed my search for new cabling for our coach. My guru buddy had installed 2/0 battery cabling for the short 4' runs from our coaches three battery bank to our recently replaced inverter. I think it was rated at 250 amps which greatly exceeds our possible uses. So I did not persue putting larger cabling in until I got around to it.
In looking around I noticed various actual sizing for similarly identified cabling.
A 4/0 might be one size but it seems a AWG designated cable might be actually larger in physical size of the bundle.
My guru buddy mentioned that country coach only used tinned wires in their coaches and noticed Foretravel had not.
No big deal to my mind at the time. That's nice.
In looking again I went to look at "marine" battery cabling and why it was specifically identified as "marine."
Plus what was the UL 1427 standards mentioned to qualify?
turns out that it was several things.
First was group three copper wires..meaning a bunch of fine wires versus bigger wires.
Second was to tin the wires to maximize their power transmitting capabilities.
Both of these I was aware of.
Aha the last difference was unexpected, turns out "marine" UL cabling is PVC coated,
So who cares? Ah the PVC itself contains chlorine atoms unlike all other materials that cover wires.
So? When heated it puts out Halogen.
It's fire resistant, std cabling is not fire resistant as it added expense is not needed in most other uses.
Coast guard specifies marine cabling for its various properties it seems.
I am probably over cautious as I spent time in the burn ward long ago but safety is very important to me.
While fires in a cable area or from the wires themselves are rare they do occur and maybe caution should be observed.
I would not run out and replace wiring but during new or upgraded installations it might be worth upgrading cabling to marine standard UL approved cabling.
The PCV may be more resistant to oils and gas than other coatings also.
Just food for thought. I think all the country coach and maybe other high end coaches 12 volt wires and cabling were "marine" type?
Did not know about the fire resistant part of the design. Wonder what Foretravel wires are made up of?
Wonder if they were aware of the difference.
Title: Re: Wiring differences
Post by: lgshoup on October 27, 2018, 02:30:16 pm
Let's see...Country Coach uses this and that and we're wondering if Foretravel understands something or other? Let's consider who is still in business and who isn't. Kind of a no-brainer...
Title: Re: Wiring differences
Post by: Caflashbob on October 27, 2018, 03:23:45 pm
What did financial results have to do with this post? That Foretravel survived under new ownership and country coach did not would seem unrelated.
The idea that country coach may have spent more on build parts quality could have contributed to their downfall?
National Rv's purchase of country coach might have dragged them down when the crash occurred.
All manufacturers have buy back agreements with the banks flooring the dealers coaches. If the dealer goes under the factory has to take the coaches back within a year.
Foretravel had no dealers. Direct sales. No buyback.
Seen a lot of funny financial deals between factories and big dealers to fake the numbers and split the excess.
Hence the buy backs to protect the banks bottom line.
I remember passing a dealers coach on the road now owned by the bank on the way to the FMCA show that I saw on the dealers lot a week before.
We called it the "motorhome shuffle."
Inverntory moving between stores was harder to count by the banks.
Foretravel has their skeletons in the closet also. Lots of interesting stories long ago. Wild and woolly rv days.
Title: Re: Wiring differences
Post by: Lon and Cheryl on October 27, 2018, 09:53:26 pm
When I pulled all my original Foretravel installed house battery cable I saw it was Marine tinned cable. I replaced with new 4/0 marine cable.
Title: Re: Wiring differences
Post by: Caflashbob on October 27, 2018, 10:20:16 pm
Thanks for the info, I thought Foretravel would not cut corners
Title: Re: Wiring differences
Post by: krush on October 28, 2018, 10:43:28 am
Second was to tin the wires to maximize their power transmitting capabilities.
My understanding is that the main purpose of tinned wire is to help reduce and prevent corrosion due to moisture...especially in the salt water environment.
As for PVC...here's a quote with lots more info at the link:
Quote
The conductor is now ready to have its insulating sheath added. Two broad types of insulation are availablethermoplastic and thermoset. The principal difference between them is that the thermoplastics soften when heated, whereas thermoset materials undergo a chemical change once they are set and will not soften. Thermosetting materials have excellent insulating properties. In addition, in a circuit-overload condition thermosets char rather than melt. They resist burning longer than thermoplastics, even when a direct flame is applied. The charred material becomes brittle and will crumble, but until dislodged they will still provide some insulation. This is in contrast to the thermoplastics, which melt down with the result that, if a short occurs in one cable in a bundle, the heat often melts the insulation on neighboring cables, resulting in additional shorts.
The primary disadvantage of thermosetting materials is their cost, which has, until recently, been prohibitive. This picture may be changing since Berkshire Electric Cable Company, in Leeds, Mass., has recently introduced a line of UL 1426 thermoset cables into the market at a more competitive price.
Of the thermoplastics, polyvinylchloride (PVC) is almost universally used for boat cable.