Why not to use solid core T+E!

AngusMcDoon said:
Yes, I along with the rest of engineering do say that. It's a result of a century of testing and experience. That's how engineering works. Engineering best practice is not to use solid core wire in applications where there is movement or vibration - hence you won't find it in a car, ship, aircraft - or professionally built boat. Crimping or ferrules on stranded wire have been found to be the most reliable way to make electrical connections in these applications. However, your boat - you do what you want or think best - but don't expect any of your connections not to vibrate when you stick the donk on.
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You will also not find solid wire in an automobile or washing machine. in fact, stranded wire is sometimes referred to as machine wire.

In the US a more finely stranded wire, known as SAE wire (available tinned), is used on engines and motor vehicles. Not strictly required on boats, but a good idea.
 
At the risk of getting rogerthebodgered, from the ISO 13297 :

18 Conductors, DC systems
18.1 Electrical distribution shall use insulated stranded copper conductors, see Table A.1. Conductor
insulation shall be of fire-retardant material.

19 Conductors, AC systems
19.1 Conductors and flexible cords shall have a minimum rating of 300 V to 500 V. Conductors and
flexible cords shall be multi-strand copper, with cross-sectional areas no smaller than those determined
using Table A.1.
 
thinwater said:
You will also not find solid wire in an automobile or washing machine. in fact, stranded wire is sometimes referred to as machine wire.

In the US a more finely stranded wire, known as SAE wire (available tinned), is used on engines and motor vehicles. Not strictly required on boats, but a good idea.
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Out of interest, do you have the spec of this wire, particularly strand thickness ?
 
Engineering has always improved by the analysis of failures.

The comet crashes is a case in point when metal fatigue was found to the a cause.

We all know know that the repeater bending of metals ca cause breakage even we don't exceed the strength of the metal.

The same with electrical wiring a solid wile will break quicker than stranded wires due to repeat bending.

In used what is called panel wire on my boat what has more finer strands than what is sold as digestive house wiring due t the potential of vibration. The downside is that crimp connecter's are needed to fine strands. (My thinking anyway)

The issue is that not everyone has that knowledge so people with less knowledge can make mistakes

We should not chastise than with lesser knowledge we should educated then if they are prepared to be educated
 
AngusMcDoon said:

ISO 13297:2020​

Small craft​

Electrical systems​

Alternating and direct current installations​


The legislation doesn't say that you can't use it. It's part of RCD so legislation says that you cannot put a new boat on the market that doesn't meet this standard, which precludes it. Once the boat is yours you can butcher it how you like.

Anyway, all of engineering says that it's not the best idea to use solid core cable on a boat, but you'd probably get away with it. You do and believe whatever you want. That's enough from me.
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I have already said that I did not do it. What I was querying was the reasoning behind it. It sometimes does to challenge those preconceptions. That is all. :unsure:
 
PaulRainbow said:
At the risk of getting rogerthebodgered, from the ISO 13297 :

18 Conductors, DC systems
18.1 Electrical distribution shall use insulated stranded copper conductors, see Table A.1. Conductor
insulation shall be of fire-retardant material.

19 Conductors, AC systems
19.1 Conductors and flexible cords shall have a minimum rating of 300 V to 500 V. Conductors and
flexible cords shall be multi-strand copper, with cross-sectional areas no smaller than those determined
using Table A.1.
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Not at all I would just like to know what i meant by :stranded copper conductors' diameter of the strands and possible minimum number of strands.

Without a minimum spec how do we know if we are complying with the RCD that applied to all standards and legislation
 
rogerthebodger said:
Not at all I would just like to know what i meant by :stranded copper conductors' diameter of the strands and possible minimum number of strands.

Without a minimum spec how do we know if we are complying with the RCD that applied to all standards and legislation
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That information is given in Table A.1. In common sizes it will be in the teens.

More practically, all commonly available stranded wire with suitable insulation and rating (not lamp cord!!) will have the required stranding.
 
rogerthebodger said:
Not at all I would just like to know what i meant by :stranded copper conductors' diameter of the strands and possible minimum number of strands.

Without a minimum spec how do we know if we are complying with the RCD that applied to all standards and legislation
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If the engineering standards are similar in format to the ones I was involved with in a software field, the standard will include a section specifying how the compliance of a system is determined. But I'm afraid that will be behind a paywall! In my field, it tended to be specified in terms of the outputs to be achieved, without specifying how they were to be achieved, though.
 
AntarcticPilot said:
If the engineering standards are similar in format to the ones I was involved with in a software field, the standard will include a section specifying how the compliance of a system is determined. But I'm afraid that will be behind a paywall! In my field, it tended to be specified in terms of the outputs to be achieved, without specifying how they were to be achieved, though.
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I understand but if anyone does not have access to the legislative requirements how can I be sure that I am in compliant.

Normally ignorance of the law is no defence but you need unencumbered access to the legislation and conditions these should be free access if used in legislation otherwise that is a simple defence in my country anyway

DocsRoom - European Commission

This link shows all the ISO standards that a RCD vessel seem to be required to comply with.

Now If I bring self boat to the EU to sell it must comply with all these ISO standards but without paying a lot of money how an I going to know what must I comply with.

Legislation is crown copyright but has an open license but the ISO standards that the legislation that the laws require me to comply with does not

This looks like taxation by stealth

We have requirements for recreation and leisure vessels published in a Merchant Shipping Act (Small Vessel Safety Regulations 2007( which is law but is specifies what is required in law so all the requirements in the appendix available to all interested parties

https://www.samsa.org.za/Acts and Regulations/Regulations/MS (National Small Vessels Safety) Regulations of 2007 as amended/MS (National Small Vessels Safety) Regulations of 2007 as amended.pdf
 
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rogerthebodger said:
Not at all I would just like to know what i meant by :stranded copper conductors' diameter of the strands and possible minimum number of strands.

Without a minimum spec how do we know if we are complying with the RCD that applied to all standards and legislation
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Buy the ISO and you will have your own copy of table A1
 
rogerthebodger said:
Why should I spend my hard earned money on something I have no used for.

excpt in the head

Why didn't you donate a oopy
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You are well aware that would be illegal.

A. I agree that it would be nice if standards were public. Ask your government to pay for them.

B. You do not have to know the standards. You can use an electrician.

Example. In my area it is no longer legal to sell many gas appliance parts to DIYs. They don't know what they are doing and the house blows up. My last boat had a small fire while off shore because the last owner bodged (just a joke!) an electrical connection under the carpet. He was an electrical engineer and had access to the NEC. Shortcuts ....
 
rogerthebodger said:
I understand but if anyone does not have access to the legislative requirements how can I be sure that I am in compliant.

Normally ignorance of the law is no defence but you need unencumbered access to the legislation and conditions these should be free access if used in legislation otherwise that is a simple defence in my country anyway

DocsRoom - European Commission

This link shows all the ISO standards that a RCD vessel seem to be required to comply with.

Now If I bring self boat to the EU to sell it must comply with all these ISO standards but without paying a lot of money how an I going to know what must I comply with.

Legislation is crown copyright but has an open license but the ISO standards that the legislation that the laws require me to comply with does not

This looks like taxation by stealth

We have requirements for recreation and leisure vessels published in a Merchant Shipping Act (Small Vessel Safety Regulations 2007( which is law but is specifies what is required in law so all the requirements in the appendix available to all interested parties

https://www.samsa.org.za/Acts and Regulations/Regulations/MS (National Small Vessels Safety) Regulations of 2007 as amended/MS (National Small Vessels Safety) Regulations of 2007 as amended.pdf
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But the standards themselves are NOT Government publications, nor are they actually part of the law. The standards themselves are available - at a price - but they are available. The law simply states that boats must comply with the RCD or whatever on the date of import. The RCD itself then refers to the ISO/BS/CEN standards. So the standards themselves are not law (just as well, as although the drafting process is VERY exhaustive, they aren't fool-proof - I know of one in my own field where there was an inconsistency between a table and a diagram; I trust it has been fixed by now as I drew it to the attention of the chair of the relevant committee!). As both RCD and ISO/BS/CEN standards are regularly revised (all ISO standards have a 5-year renewal cycle - a standard must be either revised, deleted, or extended every 5 years; a lot simply have their validity extended, but many are revised or deleted!), incorporating them in legislation directly would be impossible - parliament or equivalent bodies would spend all their time on it.

This is quite routine in many areas of law. The law simply states that a specific standard must be met; usually specifying the highest level (RCD or its UK equivalent here). That standard is usually freely available but may refer to other standards that are NOT freely available (e.g. ISO/BS/CEN). So, for example, cars must meet a specific emissions standard, which is laid down in law. But how that emissions standard is to be measured and met is NOT laid down in law; it is specified by various engineering standards, and will not be available free of charge.

Law generally specifies outcomes, not the means to achieve those outcomes.
 
Industry consumes a great deal of single strand 'equipment wire'.

I've seen a boat with single-strand wire used around the switches behind the panel, it made for an impressively neat and easy to follow loom, all nicely secured.

Most 12V wiring of any length would be unwieldy in single strand due to the gauge needed.
But if you could 'do it right' with no risk of fatigue failure it might have its place, just as we use solid bus bars instead of cables.
But even solid cable is expensive, so you won't save much and the consequences of a failure may make it not worthwhile.
Bear in mind that solid cable has less surface area for corrosion to attack, there are probably a lot of old boats out there with some solid cables still doing the job after 50 years.
 
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