What is good switchboard wiring?

[coopec43]

When I started wiring the switchboard of my yacht I watched videos, got expert advice from an auto-electrician, read that all motors should be on a separate fused circuit and there should be circuit breakers and isolation switches where appropriate. It started off very simple but got more and more complex particularly when I went for 12V as well as 24V.

I have deliberately avoided trying to make the wiring look neat by bundling cables together as I find it easier to trace circuit wiring in the event of a fault where it is not bundled.

To me the wiring in the second photo is preferable to wiring in the first photo. (If I cut each cable to an appropriate length mine would look better but as soon as I did that I lose flexibility)


What do the experts think?

[Bowdrie]

I'll answer with a question.
In which picture would a surveyor or prospective buyer find to be more indicative of professional quality work?
Perceptions shape opinions.

[coopec43]

Originally Posted by Bowdrie

I'll answer with a question.
In which picture would a surveyor or prospective buyer find to be more indicative of professional quality work?
Perceptions shape opinions.

I really don.t think a Marine Surveyor would be fooled that easy!


I think there can be a difference between "looking good" and being good in practice.

I have cables coming from the switchboard down into the bilge for the water pressure pump, bilge blower, bilge pump and galley lights. My Son said my wiring was untidy so he used cable ties to bunch them together. Does that make it better? (I suggest it could be more difficult to follow the cabling in the event of a fault. Of course cabling should be secured at frequent intervals to the boat structure)

There are the ABYC color codes for electrical cabling but I quickly decided they apply to manufacturers and not amateur boat builders.






One day (when I get a chance) I will number each cable with number tags. Then I can read the cable number and use it to identify the cable purpose from a list

[Jubilee39]

Tidiness in wiring is just not asthetic. I don't know how many boats I have repaired reported faults just by tiding up the switch gear wiring

[Wotname]

I am not an expert but here is what I think -

The first picture shows a far more professional job than the second. The second picture tells me the guy doing it was not a professional.

The wiring in the second picture may be safe and the circuits may work but I would always be left wondering who designed the circuits and did they know what they were doing.

If the job is done properly, there will be a schematic circuit, a wiring diagram and terminal function lists etc. The hardware (terminal strips, switches, fuses etc) will be designated and the designations will be reflected in the wiring diagrams and function lists.

The first step in fault finding to consult the schematic circuit and then the wiring diagram. The schematic will point you towards possible fault areas and the wiring diagram will tell you where each piece of wire is terminated. A multimeter will allow you to test each section. You should rarely have to physically pull a loom apart to follow a wire. The paperwork tells you where each end of wire is terminated. Faults are most likely to at or near the terminations or in the unit under test itself (light, switch, fuse, pump etc).

The problem with many boats is that no one ever bothers to draw formal circuits and diagrams of the wiring or at least keep the notes of the work as it is done.

The correct way to wire up a boat is to first draw the circuits, then create a point to point diagram. Do the work making notes along the way of any changes needed and then after testing, mark up any changes on the original circuits and diagrams. The resulting document is the fault finder's best friend.

If you want to get really pedantic, each wire can be numbered (and referenced on the circuit) and a bill of materials used can be created so that replacement parts can be more easily procured.

[coopec43]

WOTNAME

That's good in theory but it doesn't work that way for one off boats. (Production boats a different matter)

Assuming you have made an inventory of every component/unit you plan to install then you can do circuit diagrams.

I am now using a Panasonic Toughbook with OpenCPN as a chart plotter. I need a dedicated 12V outlet for it. I have been given a Navman depth sounder and a VHF Radio. How do I power them?

Of course changes in law may require additional equipment to be installed e.g gas detectors.

[MicHughV]

The second photo looks like spaghetti soup to my tired 'ole eyes. No telling where one wire begins nor ends. You'd have to run your fingers down the entire length of wire to find it's beginning and end.

[wholybee]

I think a surveyor might fail the second photo, or at least note a few things. The second photo uses cheap nylon terminals, and seem to have been poorly crimped with a cheap tool that probably didn't make a good connection. At least some of those connections are probably going to fail prematurely, and there is no telling what ones they will be.

The problem with the spaghetti of the second photo is that as you attempt to follow a wire, you are more likely to disturb another connection. I can't even count how many times I have dealt with that in poorly wired equipment.

I see white and blue wires going to a negative bus. And what appears to be yellow wires going to positive. That isn't right.

With a poorly wired system like the second photo, when you make a change, the wiring gets even worse. But with a well wired system, you can just follow the existing wires, and the change is invisible.

Neither photo has labels, which is a darn shame, because that addresses the OP main concern with following wires. Hopefully an up to date drawing exists, at least.

[Cheechako]

I discovered a long time ago that nobody sent the memo about anal wiring routing to the electrons!
But it does look nice.

Both your pictures look very nice to me. But they are not a good comparison because the "neat" picture #1 mostly is wiring to Terminal Blocks. The #2 pic shows less terminal blocks and maybe fewer connections to go bad! Neat does not always = good!

They are also not comparable because pic #2 is a swing down electrical panel where the other pic is a fixed in place system. To swing down you have to do some things different.

[Calaban-Alleria]

Wotname summarized issues very clearly and correctly (IMHO - retired electrical engineer, mostly software but still...).


I can tell you dont want to hear it coopec43 but its the difference between a "professional quality" job and a hack. The hack may work, and we all do them from time to time for what we convince ourselves is good reasons but still a hack.

Originally Posted by coopec43

WOTNAME
That's good in theory but it doesn't work that way for one off boats. (Production boats a different matter)

I completely disagree. Yes its more work, properly engineered systems always are. The production boat manufacturer gets to amortize that up front effort which is nice for them but that is not why quality builders go to the trouble. They do it because it helps sell boats and reduces support/maintenance costs down the road.

I am currently working through the issues with our "new to us" boat. It started out looking a lot like the 2nd picture, worse actually - but getting better.


However "your boat" so "your way".

[coopec43]

Originally Posted by MicHughV

The second photo looks like spaghetti soup to my tired 'ole eyes. No telling where one wire begins nor ends. You'd have to run your fingers down the entire length of wire to find it's beginning and end.

Doesn't that apply in the first photo also? (I think it would be harder to follow the cabling. Do you undo the cable ties?)

Of course if each cable was numbered it wouldn't be a problem.

[Spot]

Other than those hideous fluoro zip ties...what has the world come to, no waxed lacing?




Coop, brave of you to ask and offer your work for inspection. I have to say it's better than any boat I have ever bought. I hope to get my boat looking comparable this season.

In my neck of the woods, terminals in order of price- PVC (bright color) $, nylon (pastel/tint) $$, heat-shrink (longer down the wire) $$$.

[coopec43]

Originally Posted by Cheechako

I discovered a long time ago that nobody sent the memo about anal wiring routing to the electrons!
But it does look nice.

Both your pictures look very nice to me. But they are not a good comparison because the "neat" picture #1 mostly is wiring to Terminal Blocks. The #2 pic shows less terminal blocks and maybe fewer connections to go bad! Neat does not always = good!

They are also not comparable because pic #2 is a swing down electrical panel where the other pic is a fixed in place system. To swing down you have to do some things different.

I agree with you 100%. Spot on!

Mine is a "swing down panel" so the cabling has to be free to move.

"Neat does not always = good!"

[coopec43]

Originally Posted by Spot

Other than those hideous fluoro zip ties...what has the world come to, no waxed lacing?




Coop, brave of you to ask and offer your work for inspection. I have to say it's better than any boat I have ever bought. I hope to get my boat looking comparable this season.

In my neck of the woods, terminals in order of price- PVC (bright color) $, nylon (pastel/tint) $$, heat-shrink (longer down the wire) $$$.

Excellent!

How do you group cables on an instrument panel where there are so many switches/gauges/circuit breakers/warning lights?

[coopec43]

Rather than use cable ties I used PVC electrical duct (with snap on lids} to route cables from one point to another. I believe that is a far more preferable (and practical) than using cable ties. (Maybe not a pretty)