Yearly electrical debate thread

[S. Heisley]

Questions:

I have seen where people drill a hole through their spars and just pass the wire through. What are the chances of the wire sheathing wearing off by vibrating on the sides of that wood hole, thus, causing a fire to start?

Also, some people run their electric wires through PVC sprinkler pipe. I know that, in houses, water pipes can't be PVC. They have to be CPVC because of the cancer risks. So, this second question becomes a two-part question: 1) Does anyone have an idea of how severe the cancer risk is if the PVC is only carrying wire instead of water? 2) Is the practice of running electrical wire inside PVC the safest way or is there a better way when wiring a TD or TTT?

Thanks, in advance, for your answers

[satch]

CPVC is used in house water supply because you are drinking the water from it. I used pvc to run an extention cord under my tear just for protection, I don't see any problems with it.

[48Rob]

I have seen where people drill a hole through their spars and just pass the wire through. What are the chances of the wire sheathing wearing off by vibrating on the sides of that wood hole, thus, causing a fire to start?

Hi Sharon,

The chances of the insulation wearing off from friction are low, but possible.
Wood isn't very sharp or abrasive the way the rough edges of a hole in a metal sheet would be.
It would take a massive amount of vibration over a very long time for wood to rub the insulation off.

The chances of a bare wire starting a fire are very, VERY low.
The chances of the owner being shocked by touching the bare area is a lot greater.

Even if a wire, or wires lost their insulation, and touched the wood, it would not cause a fire "just because they touched the wood".
Bare wires touching each other (depending on which wires) could cause a problem if the breaker/fuse system didn't work properly, or the wire was horribly undersized for the system and the draw.

Rob

[Arne]

Every place I run a wire through anything, whether wood or metal, I put a glob of sealant on it. It won't move, so no chaffing. All other places are clipped and screwed at necessary intervals..

[S. Heisley]

Thanks, All.

It sounds like PVC and drilled wood holes will be fine to run electrical wires through.

[Larwyn]

Thanks, All.

It sounds like PVC and drilled wood holes will be fine to run electrical wires through.

Which I'm very happy to hear as my THHN is run through holes in the spars of the Escape Pod.

[Elumia]

a number of standards have been described for the RV industry:

http://www.rvia.org/Content/NavigationM ... efault.htm

12-Volt Electrical Requirements as specified by ANSI/RVIA 12V Low Voltage System Standard

120-Volt Electrical Requirements as specified in Article 551 and other applicable sections of NFPA 70, of the National Electrical Code

Fuel Systems and Equipment as specified in ANSI/NFPA 1192 Standard on RV’s

Fire & Life Safety Requirements as specified in NFPA 1192 Standard for RVs

Plumbing Systems as specified in ANSI/NFPA 1192 Standard for RVs.


Mark

[Miriam C.]

Mark I can't afford those books. Most are books you order.

The http://www.rvia.org/Content/NavigationM ... efault.htm seems to be limited in scope. Most of us do this already. Anyone got the book?

[bobhenry]

Many more threads like this and you know what will happen. A do gooder political type will pass a bill in congress that all Home built tear drops must pass a pre construction plan inspection and a construction inspection to be sure what we said we were doing is being done and safely. A final electrical inspection will be required a plumbing inspection will need to be passed for any tear with on board water. TVand cable must be inspected by a EST electrical systems technician. A wood frame construction by a Manufactured housing specialist and our frame and of course the body attachment by a DOT state inspector. A final inspection for compatability with the tow vehicle for light function as well as electrical brakes ( if applicable) and tow vehicle to towed trailer compatability will likely fall on the DMV or State police.
Ah progress and our tax dollars at work

[Elumia]

you can log in as a guest to read the NFPA books

http://www.nfpa.org/aboutthecodes/list_ ... ndards.asp

I suspect some searching on the internet will also find the ANSI 12V guide

[Arne]

one point about chaffing on wood. It won't matter. you would have wire against wood. no big deal. wood would take a life time to wear through copper wire unless you have a really terrible movement situation.

I know the wood could get wet, etc., but in a roof or wall, I have not a lick of concern about it... mainly because it just won's be a big deal.

And if you do a I described, put a blob of sealant on it, it won't move anyway.

[Elumia]

more good information here:

http://www.dot.ca.gov/hq/eqsc/QualitySt ... ectric.pdf

Purpose – This is one of a series of documents intended to clarify minimum quality standards required by
the Division of Equipment (DOE) for the Caltrans vehicle fleet.
Scope – This Caltrans DOE standard defines the minimum requirements for electrical equipment and
components added to OEM equipment for the Caltrans fleet.
Revision Date: January 14, 2004
References –
Referenced standards reflect the minimum acceptable requirements. If there are questions on interpretation
of this document please call Caltrans, Division of Equipment, Quality Assurance Branch at 916-227-9709.
• American Trucking Association “Technology and Maintenance Council Recommended Engineering
Practices Manual 2000-2001” and “Recommended Practices Manual 2002 Supplement”
• ANSI Z 535.1 Safety Color Code
• ANSI Z 535.3 Criteria for Safety Symbols
• ANSI Z 535.4 Product Safety Label
• ANSI Z 535.5 Accident Prevention Tags
• ANSI/IPC-A-610 “Acceptability of Electronic Assemblies” and J-STD-001B
• ASME-Y14.38M Abbreviations for Use on Drawings and in Specifications,
Standards, and Technical Documents
• EN 50082 Electromagnetic Compatibility – Generic Immunity Standard
• EN 55022 Limits and Methods of Measurement of Radio Interference Characteristics of Information
Technology Equipment
• FCC 47 CFR Parts 2 and 15
• FMCSR Title 49 section 393.30 Federal Motor Carrier Safety Regulations -- Battery Installation
• FMCSR Title 49 section # 393.31 Overload protection devices.
• Ingress Protection (IP) as stated in IEC Standard 60529
• IP65 Protected Against Water Jets From All Directions
• IP67 Protected Against the Effects of Temporary Immersion in Water
• IPC-A-600 “Acceptability of Printed Boards”
• IPC-A-620 Requirements and Acceptance for Cable and Wire Harness Assemblies
• IPC-CC-830 “Qualification and Performance of Electrical Insulating Compound for Printed Wiring
Assemblies”
• IPC-CM-770 “Component Mounting Guidelines for Printed Boards”
• IPC-SM-780 “Component Packaging and Interconnecting with Emphasis on Surface Mounting”.
• National Electric Code Article 551 Recreational Vehicles
• National Electric Code Article 455 Generators
• National Electric Code (NEC) 250-6 (Portable and Vehicle Mounted Generators)
• National Electrical Code (NEC) 370 (Outlet, Device, Pull and Junction Boxes, Conduit Bodies and
Fittings)
• National Electric Code (NEC) 210-7 (Receptacles and Cord Conductors)
• SAE 1938 Design/Process Checklist for Vehicle Electronic Systems
• SAE J1113-13 Electromagnetic Compatibility Measurement Procedure for Vehicle Components
• SAE J1127 Battery Cable
• SAE J1128 Low Tension Primary Cable
• SAE J1211 Recommended Environmental Practices for Electronic Equipment Design
• SAE J1455 Joint SAE/TMC Recommended Environmental Practices for Electronic Equipment Design
(Heavy-Duty Trucks)
• SAE J400 Test for Chip Resistance of Surface Coatings
• SAE J858a Electrical Terminals – Blade Type

[Miriam C.]

Many more threads like this and you know what will happen. A do gooder political type will pass a bill in congress that all Home built tear drops must pass a pre construction plan inspection and a construction inspection to be sure what we said we were doing is being done and safely. A final electrical inspection will be required a plumbing inspection will need to be passed for any tear with on board water. TVand cable must be inspected by a EST electrical systems technician. A wood frame construction by a Manufactured housing specialist and our frame and of course the body attachment by a DOT state inspector. A final inspection for compatability with the tow vehicle for light function as well as electrical brakes ( if applicable) and tow vehicle to towed trailer compatability will likely fall on the DMV or State police.
Ah progress and our tax dollars at work

You mean we are going to join the EU?

Mark good try! But TIA----------giving me numbers to look up works great for me cause I might even do it. It doesn't give your view on the questions. It just give us a bunch of proofs to go find. Thanks for the work though.

[Elumia]

I will state my opinion as such:

personally I would use stranded wire for a trailer. Stranded wire is not recommended to go in stab connectors on AC outlets sold in box stores.

I would not use wire nuts. I prefer terminal blocks. Ever notice any wire nuts in OEM wiring on your car? They almost always use connectors that have a locking mechanism.

I would separate AC and DC circuit wiring and use different color wires to differentiate them.

I've sold electrical components for a long time. There is no consensus which is the "best" connection method by any engineer. Some standards vary by country and industry are even mutually exclusive. You will find some say you gotta have "ring lugs" for all connections, but other will say the screws can still come loose and cause arcing. Some hate cage clamp connections, other say they make sense for vibrating applications because the spring is only going to get tighter on a stranded wire. Some insist on ferules for every wire....

I believe there are plenty of right ways to do it and even more wrong ways.

I say:

1. Use the proper wire size and type for the job, use continuous lengths and avoid splices. Watch bend radius - I had to replace part of the stranded wiring harness on my car's trunk lid because they broke from stress of opening and closing to too tight of a radius. Put connections where you have access to them.
2. Determine the proper circuit protection device for the job. Not all fuses or circuit breakers are the same. You can't decide which one to use solely on AMP rating. Do you really think the little $2 15A push-button circuit breaker is the same as the one in your household panel that's much bigger?
3. Read the instructions of the devices you buy.
4. If you don't know how to do #1, 2, 3 or are unwilling to do the reading and research, you might be over your head. Most of the answers are in relevant standards as they are developed with safety in mind.

Note that the NFPA 1192 standard has information regarding Propane plumbing.

Mark

[S. Heisley]

Miriam wrote:

Best receptacles are those you install right. If you buy really good fixtures with stab in they have screw downs.

If you are limited to big box stores and the less quality then get the screw down type and be sure to install them right.

Miriam: I think I'm confused. What do you mean by 'receptacle'? Are you speaking of an electrical box (e.g. junction box) or the product that you are wiring to, such as an electrical plug or light fixture?

I would prefer to use an electrical box to house each of my electrical connections but the ones I find are too thick for the TD/TTT walls and if you cut them down, you loose the screw holes. When I asked about it, I was told that most RV builders don't bother with the boxes; they just wire directly to the light fixture or to the electric plug, in the wall. ...Really? What's the best way to do it?

TIA