How to do poor wiring work and possibly burn a motorhome to the ground

[davecampbell]

Originally Posted by ImagineIF

FWIW, I tend to look at the marine requirements when I change anything in the RV. The marine requirements use voltage drop as a critical variable, either 10% or 3%.
Gi

NEC has a section specifically for motorhomes, it seems rather sketchy (at least my 1993 is...) it doesnt have ampacity for battery cables

It also requires copper terminals and Alfa used steel.

[davecampbell]

Originally Posted by FormerBoater

The "rat's nest" shown in the second photo is very disconcerting IMHO.

From what I learned, many/most RV manufacturers let the electricians terminate the wires with whatever crimping tool they happen to have in their tool belt. This tool is usually a cheap single indent crimper intended for only un-insulated ring tongues. The result is torn/broken insulation and a poor connection before the unit even leaves the factory.

100% Molex manufactured terminals and splices crimped in Molex application tooling
"Rat's Nest Free" electrical system

Yes, disconcerting and if I was an inspector it would be rejected for "not being workmanlike conduct."

Terminals are EXTREMELY difficult to properly crimp, Ive had expensive ($300 a piece) Molex factory hand crimp tools that werent even reliable. 1-2 / 10 failures Yes, many /most terminals in this rig were just 'center punched' with the wrong tool and frankly, they are too large to hand crimp, it takes a machine. I squeeze the barrel so the wire cant move, then solder them all. They will last 50-100 years.

Alfa used steel terminals which are going to be replaced with copper. Corrosion risk.

Then, instead of properly hanging the wires, they covered them all in convoluted tubing, which reduces the current rating.

[ImagineIF]

Dave,

I'm surprised that steel terminal lugs are even made any longer. Maybe, they are tinned copper.

Here's a link that shows current capacity by length and gauge. Thre are better ones out there that allow you to input the varibles and they tell you the gauge or current capacity. This was just one of the first I came by.

http://www.westmarine.com/webapp/wcs...ge=Marine-Wire

Gil

[davecampbell]

West Marines data is not acceptable:

1.) issued/stated to be their "proprietary" data, not traceable to any reliable source. I dont take the "data" of a company that sells materials as an authority where safety is critical. It must have been generated by an engineer, or someone really good with heat transfer, because its a critical safety factor. There is no mention of calculations, or methods to get the data.

2.) They are incorrect in citing:

"Maximum current is 15% less in engine spaces, which are assumed to be 20¼C hotterMaximum current is 15% less in engine spaces, which are assumed to be 20¼C hotter"

We can measure such things. I refused to step on a boat one day because the operator assumed they had enough fuel to make it back. I assumed he didnt, and my assumption is perfectly safe.

I dont assume things where there are possible fires and fatalaties. Not many ways worse to go than burning up.

SAE J-378 gives an almost 50% reduction in current for engine compartment wiring, by one source in England. At least they cite a reliable Standard. I havent verified it, but thats in the works.

3.) "Conductors are not bundled: If three conductors are bundled, reduce maximum amperage by 30%"

is not acceptable by NEC since NECs bounds are essentially "ambient temperature" for raceway, etc not just some arbitrary figure on the number of cables, and some vague description of "bundled" (Art 310, 1993)

Whats "bundled?" Strapped together every 3 feet, or run through continuous tubing? Either way, the accepted calculations by NEC specify wire gauge/insulation per ambient temperature and that is situational, and based on measurement, not some vague generalization on number of cables.

the point is not the number of cables, its the ambient air they have to reject heat into.

4.) They also appear to have picked their own wire standards, citing that they think theirs is better than SAE. But, NEC requires adherence to SAE standards for motorhome use in Art 551-10, 1993

Im gonna go get a new NEC....

So, in short, they can make any claims they like. They can sell you bullets, its just up to you not to shoot yourself in the foot with them.

[FormerBoater]

Originally Posted by davecampbell

Yes, disconcerting and if I was an inspector it would be rejected for "not being workmanlike conduct."

Terminals are EXTREMELY difficult to properly crimp, Ive had expensive ($300 a piece) Molex factory hand crimp tools that werent even reliable. 1-2 / 10 failures Yes, many /most terminals in this rig were just 'center punched' with the wrong tool and frankly, they are too large to hand crimp, it takes a machine. I squeeze the barrel so the wire cant move, then solder them all. They will last 50-100 years.

Alfa used steel terminals which are going to be replaced with copper. Corrosion risk.

Then, instead of properly hanging the wires, they covered them all in convoluted tubing, which reduces the current rating.

I recommend that you re-terminate with tin plated copper terminals. Anything larger than 12-10 awg will require some powerful tooling. While soldering is one solution, solder joints can sometimes be too brittle in a high vibration environment. Amp (now part of Tyco) makes a rota-crimp tool that crimps up to 4/0 uninsulated terminals. If you buy the Amp rings and post insulate with heat shrink tubing you will have the best of all worlds, but the crimper is a bit of an investment.

The Rota Crimp tool with ratchet is Amp/Tyco part number 601129-2 and will crimp 8 awg thru 4/0 uninsulated Amp Solistrand terminals and splices. The ratchet assures you the proper crimp.

I worked for Amp from 1977 thru 1990 but have no current affiliation. Spent most of my career in the terminal, splice and connector world.

Good luck with your project.

Dave

[ImagineIF]

I invested in this tool years ago when I had to do a lot of work on boats.
http://www.amazon.com/Greenlee-K09-2.../dp/B000LDGRV2

I agree that tinned copper terminal lugs are the way to go. Also, as stated previously soldering may not be the most effective if vibration may occur. I like terminal lugs without the solder drip hole. I crimp the lug and add some sealant at the lub to cable joint and finally cover the joint with shrink wrap.

Gil

[rough road]

A very large manufacturer of both crimp and solder terminations states that soldering lugs, if done properly, makes as reliable a connection as crimping-and in the instance of hand held crimpers, used in tight spaces soldering is far more reliable. The key is to use pre measured pellets which will not wick up past the lug, and using a high quality heat gun to do it is very easy.

One of the questions I have is just how much of this was from the factory, it looks bad enough to have come from Phoenix USA RV.

[zmotorsports]

Originally Posted by ImagineIF

I invested in this tool years ago when I had to do a lot of work on boats.
Amazon.com: Greenlee K09-2GL K-Series Crimping Tool, 8-4/0 AWG: Home Improvement

I agree that tinned copper terminal lugs are the way to go. Also, as stated previously soldering may not be the most effective if vibration may occur. I like terminal lugs without the solder drip hole. I crimp the lug and add some sealant at the lub to cable joint and finally cover the joint with shrink wrap.

Gil

This is similar to the crimper that I have used for the last ten years. Mine has a ratcheting mechanism built into it which helps tremendously. I have also soldered when in a tight location and have had great results with both methods. Mike.

[davecampbell]

Originally Posted by FormerBoater

I, solder joints can sometimes be too brittle in a high vibration environment.
Dave

Ah. I see you have been around. Yes, solder is weak (tin lead alloy, extremely poor strength) which is why I spend far more time in vibration proofing everything and paying particular attention to wire dress - length - routing - fastening than in applying connectors.

Everything is being rubber mounted...diesels give off a ridiculous amount of vibration.

[davecampbell]

Originally Posted by zmotorsports

This is similar to the crimper that I have used for the last ten years. Mine has a ratcheting mechanism built into it which helps tremendously. I have also soldered when in a tight location and have had great results with both methods. Mike.

Wouldnt touch it with a ten foot pole. Nice looking unit, the usual fantastic claims of "UL" and "wonderful quality" but the main question is not answered:

"Are the crimps formed according to the manufacturers crimp profile requirements?"

Once upon a time, I had a shop of kids throw out a pile of wiring harnesses because even the factory Molex tooling didnt work correctly, and they had no idea they were doing poor quality work. They thought it was OK.

Its an entire science by itself to get a PROPER crimp. Crimp it, saw it apart, polish it, put it under a microscope and show me a couple cross sections, then I might buy one. Greenlees word that its a great tool isnt enough.

And this is meaningless

"UL and cUL classified"

"Classification" doesnt mean it makes good crimps, it could mean it simply is designed to not pinch the users fingers off.

UL | Marks - Appearance & Significance

It isnt enough to claim it works with a certain manufacturers product line, each terminal (or series) may have / has different crimp requirements.

[davecampbell]

Originally Posted by FormerBoater

The Rota Crimp tool with ratchet is Amp/Tyco part number 601129-2 and will crimp 8 awg thru 4/0 uninsulated Amp Solistrand terminals and splices. The ratchet assures you the proper crimp.

Dave

To belabor a point, notice that it works ONLY for specific terminals (I know you understand that as youve worked in the industry, but the point may get lost on others)

Proper crimp on ONLY those terminals (not the similar ones from the hardware store that some Chinese supplier dumped...), and ONLY with the proper tool, proper tool adjustment and testing, correct terminals, application methods...

"Crimps - are they correct, or are they fire starters??"

I once saw an insurance claim where an electrician pulled a cable through a wall, kinked it, which burned a $300,000 house to the ground.

[davecampbell]

And for more from the Alfa QC dept:

* ground terminals fastened to painted surfaces with black oxide screws
* AC circuit ground fastened along with a DC ground wire (major No-No)
* 3/8 terminal on 5/16" stud
* ends of convoluted tubing not taped together so the tubing falls off (there must be 17 miles of convoluted tubing in this vehicle)
* wrong kind of wire used (THHW or -"tri-bendin")
* AC supply wire to inverter too small (12 instead of 10 AWG)

All this quality in a flammable box full of diesel fuel !

[FormerBoater]

Originally Posted by davecampbell

To belabor a point, notice that it works ONLY for specific terminals (I know you understand that as youve worked in the industry, but the point may get lost on others)

Proper crimp on ONLY those terminals (not the similar ones from the hardware store that some Chinese supplier dumped...), and ONLY with the proper tool, proper tool adjustment and testing, correct terminals, application methods...

"Crimps - are they correct, or are they fire starters??"

I once saw an insurance claim where an electrician pulled a cable through a wall, kinked it, which burned a $300,000 house to the ground.

The UL and CSA certifications are as you point out for Amp Solistrand TM terminals and splices only.

Amp has other application tooling producing a W crimp configuration on their Solistrand terminals that meet the more stringent requirement of Military Specification MIL-T-7928. These tools and dies are extraordinarily expensive.

Terminal manufacturers must submit their product crimped in specific application tooling to use the UL and CSA marks. But as you point out, the marks are meaningless unless you use the terminal manufacturers approved crimping tool or dies.

Voidless mass and calibration to crimp where electrical performance and mechanical strength intersect on a performance chart is what Amp, Molex, Thomas & Betts and Panduit do in their designing of solderless terminals,splices and application tooling.

You are taking the extra steps to protect those solder joints and have the skillset to use the solder properly. Quality solderless terminals and the approved application tooling make it possible for most people to make a safe, UL, CSA or Mil-T-7928 approved termination depending on the product type and application tooling used.

Dave

[two-niner]

So, who is the owner of this now mil-spec'd Alfa ?

Kerry