Legalities of electrical work on recreational vessels in QLD

[finga]

Finga - interesting post indeed. I always over-engineered wiring anyway to be safe. For example if the manufacturer of the windless says recommended 20 amps..I go 30 etc, so in the past I have thought things out but clearly knowing the standard is better.

In the above quote I don't understand though what the gentleman is saying. Is he saying that the standard quoted is actually for commercial vessels only but that he would strongly recommend that anyone re-wiring or adding to a recreational vessel adopt that standard anyway, or is he saying there is a part of the standard that specifically says it applies to recreational (or all) vessels?

Cheers

Which quoted standard?
AS/NZS 3004.2 is specifically directed to recreational boat installations and has nothing to do with commercial vessels.

The National Standard for Commercial Vessels Part C Subsection 5B Electrical is the standard for a commercial vessel's electrical installation and is a good electrical standard for recreational boats.
It has a lot of good work practises in it which are much stricter then the minimum requirements set in AS/NZS 3004.2
It's a bit like using 8 inches of concrete when 4 inches will do in your home driveway.
It would be regarded as overkill in the eyes of some but necessary if you didn't want it to ever break up.
Remember...these standards are the bare minimum requirements needed.
You can always go better and feel safer, which you seem to have done.

[ozscott]

There appears to be an extract on http://infostore.saiglobal.com/store...ductID=1022723 as follows:

"Abstract

Specifies requirements for electrical installations on small boats (viz boats with a maximum length of 50 m).
Scope

This Part of AS/NZS 3004 specifies requirements for the design, construction and installation of electrical systems in recreational boats that have a length of up to 50 m, and are designed for use on inland waters or at sea. It is not intended to apply to small boats equipped with a battery supplying circuits for engine starting and navigation lighting only that are recharged from an inboard or outboard engine driven alternator"

Thats a bit ambiguous - however it appears to mean that the standard does not apply if all you have is a traditional outboard with batteries being charged by the motor and nav lighting, but does apply if you have more than nav lighting - ie with a VHF radio say, or a bilge pump....

Cheers

[finga]

That is correct.
If your boat has anything more then a battery charged from your electric start engine and navigational lights you need to follow AS 3004.2.
But I think navigational lights are cover by a standard through COLREG's if someone wants to search for it.

[oldboot]

Again Finga you quote and use my comments out of context.

and you take an obtuse and unrealsitic example.


There is one and only one reason wiring, apart from wiring in starter and main battery circuits cause a fire and that is INCORRECT FUSEING. nothing to do with voltage drop.

AND back to the email it says "compliance with the standards is a way to meet one's general safety obligation"

Not "the way" or "the only way".

He also uses the word recommend......no compulsary, not mandatory, and given he is a government beurocrat, he has nothing he can recommend other than an existing document, there being nothing in the legeslation this means a standard..

If compliance with electrical standards was as important an issue as the carrage of suitable safety equipment, the government would be advertising it in as prominent a manner.


we come back to the question at hand.."LEGALITY"

the safety equipment may be a similar situation to the electrical matters but they are not the same.....similar but not the same.

Plainly if the wiring in a boat causes a fire...it was NOT generaly safe and fit for purpose.

If an anchor winch is wired with wire that in theory according to the standards is too small, but even so, it functions adequately and being correctly fused it can not cause a fire........it is generaly safe and fit for purpose.......GSO satisfied.
Perhaps the winch is designed to cope with out of standard voltage drops.

Likewise it is possible that, a given winch may not operate correcty even though the cabling is to standard, its design or application may require considerably heavier cable that required by a standard.

If I have LED navigation lights that provide equal brightness from 8 volts to 16 volts and the wiring is correcty fused.....even though the voltage drop may be out of spec ( it wont be, but lets say it is) is not that situation generaly safe and fit for purpose.

Standards are not everything.

What is legal and what you or I would do is another completely different thing.
I would never argue that an inadequate cable should be fitted to anything.

Even if we are judged by the standards there are various methods to achieve that......Overkill is a very popular method of compliance......even some of our best engineers and some of our construction and even electrical regulations work by overkill rather than calculation.

AND just because it is compliant with standards, it does not necessarily mean that it is generaly safe and fit for purpose.

It would be quite reasonably possible to DC wire a whole boat with out doing one single calculation.......its compliance with standards could be confirmed by measurement and inspection.......don't we all inspect and test our electrical work prior to calling it complete.

Even more so, it is entirely possible in complete ignorance of the standards, but using good engineering practice to DC wire an entire boat and have it be compliant with standards or at least generaly safe and fit for purpose..........as this seems to be a very common occurance possibly the rule rather than the exception in safe boats.


Possibly a far less common occurance than boats wired in ignorance and being a total death trap.

following from this thread I am keen to make myself familiar with the standards that have come to light, and my preferance would be to comply with them.

But that would be my own free choice and not because of any sence of mandatory obligation.

cheers

[PinHead]

I wired my tinny..from battery to nav lights, all round light..onboard lights, bilge pump, vhf radio and sounder...did i read up on any code? nope! is it all legal? dunno. Does it all work? definietly! will I ever get a penalty for doing it myself? absolutely not? so why bother about it??

I would much rather people learnt more about boat handling than so called wiring rules.

[oldboot]

Here is one for Finga.

cut and pasted from here

http://www.acbsphl.org/Tips_and_hints/ABYC_Wiring.htm

Ampacity is the ultimate safe current carrying capacity of the wire before damage
occurs to the insulation, without regard to voltage drop. Because the insulation of most SAE wire types is not the same as ANCOR, this chart should not be used for other conductor types. Use Table C & D to find proper wire size to insure adequate performance.


DAMN...... the table ... wont paste across

any way follow the link and be affraid.

25 amps on 1mm2 cable......... ........ and that is from a standard.

Scary eh.

cheers

[finga]

Here is one for Finga.

cut and pasted from here

http://www.acbsphl.org/Tips_and_hints/ABYC_Wiring.htm

Ampacity is the ultimate safe current carrying capacity of the wire before damage
occurs to the insulation, without regard to voltage drop. Because the insulation of most SAE wire types is not the same as ANCOR, this chart should not be used for other conductor types. Use Table C & D to find proper wire size to insure adequate performance.


DAMN...... the table ... wont paste across

any way follow the link and be affraid.

25 amps on 1mm2 cable......... ........ and that is from a standard.

Scary eh.

cheers

Please correct me if I'm wrong but I understand those ratings to be for only 1 linear foot of single way circuit length of cable.
read AND understand the entire standard.
Work out the current ratings for about 3 feet of single circuit ....and see what you get?
Do a calculation for 20A for 3 feet and 3% voltage drop and you'll come up with about 2mm cross sectional area cable is required.
Do a calculation for 20A for 10 feet and 3% voltage drop and you'll come up with about 8mm2 cable required.
Then work out the cabling Andy's way for 2.5mms tinned flex with 20A load for 3 and 10 feet and 3% voltage drop using V60 cable.

Like I said before....a little bit of information can be dangerous.

That includes me because I could not be bothered to see what a single circuit length of cable is defined as in that quoted standard so the above calculations may well be extremely wrong.

[Captain Seaweed]

Thats correct, current carrying capacity involves, type of cable,type of enclosure, temperature (ambient or not) and length and also protective device , I believe.

[finga]

You believe rightly Capt...plus a few others if you want to get real technical...but we don't want to.

[oldboot]

It does not matter how long the cable is or what voltage drop you calculate 25 amps down 1mm2 cable is a very big ask.

That is more than twice what our standards allow for and more than twice what any of our cable manufacturers would rate the cable.

cheers

[Fed]

Ampacity is the ultimate safe current carrying capacity of the wire before damage occurs to the insulation, without regard to voltage drop. Because the insulation of most SAE wire types is not the same as ANCOR, this chart should not be used for other conductor types. Use Table C & D to find proper wire size to insure adequate performance.

If you read that carefully Oldboot I don't see a problem with 25A - 1.0mm²
They are not saying it's ok to use 1.0mm² cable for 25A only that their (ANCOR) insulation starts melting at that point.

[finga]

It does not matter how long the cable is or what voltage drop you calculate 25 amps down 1mm2 cable is a very big ask.

That is more than twice what our standards allow for and more than twice what any of our cable manufacturers would rate the cable.

cheers

It bloody does matter how long the cable is and where/how it's run.

What's a real short bit of wire called??
Answer is a fuse and it carries the current no worries. That's it's job.

2mm is about a 140A fuse.
1mm is about a 55A fuse.

I'm starting to tire of this.
Do what you want. I don't care any more.
If you want a 13 foot long bit of fuse wire in your boat then do it..but suffer the consequences.

I just pray to God you never have to have a real unfriendly chat to blokes who wear funny wigs....
And the praying will be for the people who have been harmed.


Besides the way....why mention standards.
You reckon they're all a pile of crap and everything can be worked out with common sense, ohm's law and a multimeter and that there is no legal obligation to follow even after getting advice from a senior advisor (maritime) of the Safety Standards Branch within Maritime Services Queensland who highly recommended wiring in small boats should follow the requirements of AS 3004.2:2008 in the same regard as Maritime Services Queensland can only recommend skippers to have a paddle, water and an anchor on board their boat to meet their safety obligation under the Transport Operations (Marine Safety) Act 1994.
.
The telling is in the pudding.
See what would happen when the poo hits the fan.

[Defore]

See what would happen when the poo hits the fan.

The room gets covered in shit.

You normally only make the mistake once of throwing a baby's used nappy up in the air with the ceiling fan running.
It was a good joke until the nappy hit the fan

Ian

[oldboot]

I do read things in their entirety, unlike many others here.

And one thing that quite a few don't seem to grasp is that the "current carrying capacity of a cable" stands alone as a specification for the cable and the cable alone.

It is most usually specified at a specific tempeature and with the cable in open air laid straight.

It specifies what maximim current the specific cable is capable of safely carrying (with or without a safety margin) before some sort of "material failure". In insulated cables that is usualy the insulation melting.

This remains the same once critical length is achieved, critical length is where the the cable is long enough to be consistently measured.

This is the figure specified by manufacturers and in many tables that can not account for the use or method of installation.

It is the starting point.

Those of us that have not had our heads burried in electrical industry standards and blinkered by the methods specific to those standards will recognise this valid and real specification for what it is.

I have many electrical standards here relating to building industry electrical including AS3008.

I know there are tables upon tables and a couple of formulars for current carrying capacities for cables of specific lengths and in specified situation or methods of installation. Most of them totaly irrelivent outside of the building industry.

BUT

These are not the nominated current carrying capacties of the cable its self in isolation, as would be found in any cable catalogue.

I am only too well aquainted with methods and means specifying cable IN SITUATION both those methods contained in standards and other valid methods used in engineering.

Voltage drop is completely irrelivent in calculating current carrying capacity of cable in isolation.

Regardless of length once critical length is achieved, the same or similar amount of current in cable or wire will result in failure........the same amount of energy is disipated per unit length......voltage drop is irrelivent untill there is insufficient voltage remaining to make sufficient current flow.
Sure you coud use volatge drop in one method to calculate this failure..... but no one has even touched on such a method.

Failure to grasp the concept of current carrying capacity of a cable in isolation is to fail to understand one of the simplest facts about cable and how it is specified.

Believe it or not, there is an electrical world that exists out side of the building industry standards, and believe it or not outside of the " electrical industry" voltage drop is not the all consuming matter.

Even in the electrical industry voltage drop is not the all consuming thing that it once was.

YES that is right, voltage drop is no longer the predominating factor in the building industry electrical world......FAULT LOOP IMPEDANCE is....all the smart and well informed electricians are working off Fault Loop Impedance tables, because if the FLI is correct so will the voltage drop but not the other way arround........but that is not relivent in DC wired boats.

now back to the link to a table from the ABYC standards.

No australian manufacturer I know would speciffy 1mm2 cable at 25 amps, Like it or not in this country we work off arround 10 amps per mm2 for light cables under 2.5mm2 above that there is a correction for conductor bulk


I posted the table to iilustrate that the americans (particularly in automotive and marine) would allow far more current in cables that we would expect to....and this is definitely indicated by the way our cars are wired.

25 amps in 1mm2 cable of any length in any insulation....... not comming out of my workshop unless it was a fusable link.

AND this is the point.

Once a cable is short enough or if voltage drop is not a consideration, we need to know and understand the safe current carrying capacity of the cable in isolation.

So we can select an appropriate cable AND we can select a suitable fuse or breaker.

As I have said I am well aware of the "other factors" involved in selecting a cable, but that do not impact on specifying the cable its self.

cheers

[finga]

What are you waffling on about??
You lost me after I do read things in their entirety, unlike many others here.
Simply put.... I just didn't want to read any more because I couldn't be bothered after reading things like critical length and crap like that.