DC cabin lights wiring

[SailRedemption]

Originally Posted by funjohnson

Instead of 4 pages of posts...just add up all the LEDS that will be on this circuit, figure-out the max length from end light to panel, and then calculate the voltage drop for each gauge of wire available. Less than 10% is recommended for general lighting circuits, but I would add a buffer for when someone taps into this line for something down the road.

16awg should be fine, but on a 47' boat you could have a lot of lights or a real long distance from panel to the last light.

Good luck.

Matt

I did. At moat I can have 5 lights on one string, that's 1amp. I I doubled the amps to 2. Then the longest run in my boat with a panel in midship, is at most 40 total run(the lights aren't at the ends of the boat) 16ga is what I get. I just didn't post it because the thread has veered a bunch and I already got the advice I needed.



I'll be using 18ga house romex, wire nuts, and I'll use the circuit breakers I had left over from building our shed. That should be good enough, right?

(:

- Ronnie...on the geaux

[W3GAC]

Well it would certainly be more organized to have all the in-line fuses organized/ easy to get to. Don't know of a block of 3A G fuse holders, but googled multi-fuse holders and a source came up... think it was Littlefuse. If you can!t find such a panel, easy enough to make one by selecting a panel material a drilling row, rows, or matrix of appropriate diameter holes for the 'twist & lock' 'tubular' glass fuse (3A G) holders available at marine, auto, Radio Shack stores. Might be worth googling auto electronics suppliers fir a multi- AG, I believe the typical auto fuses are called. They are a lit less lonely to develop corrosion issue. Yes, I suppose after the breakers would be better. Good luck. Good luck!


Sent from my iPhone using Cruisers Sailing Forum

[bellrock]

Thanks for the help. The west marine distibution panel has 15 amp breakers whcih are not, as far as I can tell, removeable/ replaceable with other amperages. If 15 amp breakers are fine with 16 guage wire, I'm fine with leaving as is.. but the original panel on this boat ( a fuse panel bpard) contained alot of 3 and 5 amp fuses.. so if the wire is ok with a 15 am breaker, whats the risk of not putting in a 3 to 5 amp in line fuse for the lighting (mast ,running lights), circuits?


Cost is certainly an issue, but saftey is a bigger issue.

[mitiempo]

These fuse blocks are available from Blue Seas for AGC and ATO fuses. Much neater than individual inline fuse holders.

[mitiempo]

Originally Posted by bellrock

.... I'm fine with leaving as is.. but the original panel on this boat ( a fuse panel) contained a lot of 3 and 5 amp fuses.. so if the wire is ok with a 15 am breaker, whats the risk of not putting in a 3 to 5 amp in line fuse for the lighting (mast ,running lights), circuits?

There is no risk but also no real gain. The fuse (or breaker) is there to protect the wire, not the load item. The 15 amp breaker protects 16 awg wire - 16 has an ampacity of 21 in engine spaces and 25 outside engine spaces. Adding additional fusing will add to the cost and complicate things. When a circuit has a problem you will have to check both the breaker and the inline fuse. It also adds extra connections that could be a problem in the future.

[W3GAC]

Yes, 15a ok for 16ga. But the issue is a very small gauge 'pigtail' wire that comes with the LED lights. Depending on the light, there might be enough room within/ under the typical LED replacement dome to put an inline between the feeder 16 ga and the 22ga LED pigtail. The West brand has enough room the last Dr LED I purchased didn't. Also, despite the Label, the 6 Dr LED domes I purchased (and returned) created severe RFI to SSB/ 6m ham spectrum. West and others didn't.
I can turn all my LED house lights on and the boat can be a bright as an Operating Room, but only 2.5a load!



Sent from my iPhone using Cruisers Sailing Forum

[mitiempo]

Originally Posted by W3GAC

Yes, 15a ok for 16ga. But the issue is a very small gauge 'pigtail' wire that comes with the LED lights.

I wouldn't worry about the small gauge pigtail on the light fixture. A dead short in even 22 gauge wire will pop a 15 amp fuse. You could shorten the pigtail to the minimum if you want.

[rwidman]

Originally Posted by mitiempo

15 amp breaker is a good choice - as all Blue Seas panels are equipped with - as long as you size the wire properly - 14 awg.

Considering the small gauge pigtails mentioned above with some LED fixtures, selecting overcurrent protection that's a little above the maximum current drawn is good safety practice. Not mandatory, perhaps, but good practice.

[rwidman]

Originally Posted by jheldatksuedu

Never say never, it certainly is possible to short out a circuit breaker panel, not likely but a wire could come loose or a tool fall against a terminal.

That's why we use ring terminals and enclose the panel.

I'm sure the person asking the question is not interested in normal or proper, he just wants to be safe and cost is a big motivation in his proposed modification. New circuit breakers for the panel could easily be well over $100 where a collection of series fuses and holders might be something in his junk drawer and even if bought new would probably be much less than $20. ........... .

Standard circuit breakers for typical panels are $14 each on line. How many could he need for lighting circuits on a boat? If $14 for safety is an issue, one needs a cheaper hobby.

Let's not make this project any more complicated than it needs to be. And let's not taco up his boat with a circuit breaker panel and hidden fuses behind it.

[rwidman]

Originally Posted by jheldatksuedu

Never say never, it certainly is possible to short out a circuit breaker panel, not likely but a wire could come loose or a tool fall against a terminal.

That's why we use ring terminals and enclose the panel.

I'm sure the person asking the question is not interested in normal or proper, he just wants to be safe and cost is a big motivation in his proposed modification. New circuit breakers for the panel could easily be well over $100 where a collection of series fuses and holders might be something in his junk drawer and even if bought new would probably be much less than $20. ........... .[/QUOTE]

Standard circuit breakers for typical panels are $14 each on line. How many could he need for lighting circuits on a boat? If $14 for safety is an issue, one needs a cheaper hobby.

[Sailorman Ed]

I'll be using 18ga house romex, wire nuts, and I'll use the circuit breakers I had left over from building our shed. That should be good enough, right?

Almost, but better to use up the old aluminum wire and some old round fuses. Hope you are using the old corrugated BX cable and the steel boxes

I have used the 18 ga cable for LED lights as I often need to thread the wire thru some very tight spaces and make some tight turns - 14 or even 16 would just not fit.
BTW, these: https://www.superbrightleds.com/more.../Photos&Videos make some very nice bright light in the galley.

[rwidman]

Originally Posted by Sailorman Ed

Almost, but better to use up the old aluminum wire and some old round fuses. Hope you are using the old corrugated BX cable and the steel boxes

I have used the 18 ga cable for LED lights as I often need to thread the wire thru some very tight spaces and make some tight turns - 14 or even 16 would just not fit.
.

You need a "hole bigginer".

[SailRedemption]

Originally Posted by Sailorman Ed

Almost, but better to use up the old aluminum wire and some old round fuses. Hope you are using the old corrugated BX cable and the steel boxes

I have used the 18 ga cable for LED lights as I often need to thread the wire thru some very tight spaces and make some tight turns - 14 or even 16 would just not fit.
BTW, these: https://www.superbrightleds.com/more.../Photos&Videos make some very nice bright light in the galley.

Haha yea the bx! Jeezum! Haha!

Yea I have these lights from there for my engine room, have 7 of them.

https://www.superbrightleds.com/more...-fixtures/622/

Very bright and I'm excited to hook them up. Just going to 3m vhb tape them up. And put an exterior home lever switch for them.

- Ronnie...on the geaux

[hpeer]

Funny, I've gone the other way, I'm wiring the house as a boat!

We have an old row hose, 4 apts. The hallway lighting wire is small gauge and very old. I would like to replace it but it runs circuitous routs through 14' high lath and plaster ceilings. The walls have studs, then half way up there is another "header" then more studs. Rewiring the seven lights would probably cost $10k in labor.

So I eventually found some 100W equivalent, 12vdc screw in type LEDs and changed the circuit over. I'm running it off a security system power supply that charges a battery and switches to the battery in case of power failure.

But the building inspectors still made me keep the stupid emergency hallway lights, even though they are now redundant. So we had to have them put on a second circuit. But that is new wire and parallels the fire alarm system in wiremold. Not pretty, but since it follows the existing wire,old it looks no worse. Doing the lights like that would have looked like hell.

Just that little project cost us almost $3k.

But, electrical wiring degrades over time due to the electrical stress. Eventually it's withstand voltage gets lower and lower raising the risk of a short and fire. By lowering the voltage we have substantially lowered the risk of the wiring failing somewhere in the wall. 110vac arcs far easier than 12vdc.

Unorthodox but it's working as desired and meeting all codes and saving some amps to boot. The light is even better than the old incandescent or flourscents we had in there.

[exMaggieDrum]

Originally Posted by Sailorman Ed

I have used the 18 ga cable for LED lights as I often need to thread the wire thru some very tight spaces and make some tight turns - 14 or even 16 would just not fit.
BTW, these: https://www.superbrightleds.com/more.../Photos&Videos make some very nice bright light in the galley.

I've used 18ga wire a few times when I really had to, just like you. I understood that the insulation was not as thick so would not be as abrasion and pull resistant and the thin wires inside ditto. So I had to take special (even more than usual) care when pulling and installing the wires.

It's great we can put LEDs everywhere now. So much better. My only gripe is it is hard to find "soft or warm" color LEDs. The harsh white LEDs are not pleasant on my eyes and actually not as good to read by (for me).