DC cabin lights wiring

[rwidman]

As I read through this thread, there is some good and accurate advice, but some very, very bad advice. The problem with getting advice on web forums is that anyone can post but unless you already have a good idea, you can't easily tell the good from the bad.

[Stu Jackson]

Originally Posted by SWTFRDOM

The problem with wiring in series is that one light goes out, they all go out.

Doesn't anyone remember 1950s Xmas lights? I'm surprised it hasn't been mentioned. Oh, wait, during Xmas season people like to light up their boats like: Xmas Trees!!!

[Stu Jackson]

Originally Posted by rwidman

As I read through this thread, there is some good and accurate advice, but some very, very bad advice. The problem with getting advice on web forums is that anyone can post but unless you already have a good idea, you can't easily tell the good from the bad.

Good advice, Ron. I'm sure someone will point out the incorrect ones.

I'm sure the respondent who said he used "only" 16 ga wire all over, 'cuz that's what he had, will be fine with his installation.

I have factory OEM 14 ga wire and crappy connectors which dims the first light when the second one comes on, and just gets worse as more come on.

But whadda I know, they're all incandescents!!!

I haven't yet been able to justify the exorbitant cost of LEDs to save 4 ah a day. Unless you're profilgate with lighting, there just isn't that much to save unless you don't have a fridge. Based on almost every single energy budget I've ever made or seen.

But anything less that 12 ga makes little sense to me, 'cuz teeny tiny connectors are NO FUN to make.

Good luck with "brain salad surgery" wiring.

What's wrong with a little extra sized wiring for lgihting?

[SailRedemption]

Originally Posted by Stu Jackson

Good advice, Ron. I'm sure someone will point out the incorrect ones. [emoji14]eace:

I'm sure the respondent who said he used "only" 16 ga wire all over, 'cuz that's what he had, will be fine with his installation.

I have factory OEM 14 ga wire and crappy connectors which dims the first light when the second one comes on, and just gets worse as more come on.

But whadda I know, they're all incandescents!!!

I haven't yet been able to justify the exorbitant cost of LEDs to save 4 ah a day. Unless you're profilgate with lighting, there just isn't that much to save unless you don't have a fridge. Based on almost every single energy budget I've ever made or seen.

But anything less that 12 ga makes little sense to me, 'cuz teeny tiny connectors are NO FUN to make.

Good luck with "brain salad surgery" wiring.

What's wrong with a little extra sized wiring for lgihting?

Stu, I'm not sure if you're directing at me regarding the 16ga wire. But if you are, "anything less than 12ga" is overkill for LED lights in these short distances. The connectors are not THAT small. I have no problem crimping them with the correct tools and crimps. Well like anything on a boat, I'm looking at a system approach so the lights/bulbs are getting changed with the wire. No sense in doing a half cooked job.

The problem with extra sized wire is: cost, physical size when running through boat, weight(it adds up), and unnecessary for the application.

Thanks for the luck though! I'll no doubt need it come time to run the new wire wherd the old were.

- Ronnie...on the geaux

[Matt Johnson]

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

[GrahamHO]

Quite correct RWIDMAN. I didnt want to add complication. Also I'm not sure of voltage tolerance of LED lamps. Certainly true for incandescent lamps. Once upon a time long long ago street lights were in series. SAILREDEMTION should make himself aware of the difference between parallel wiring and series. He can easily Google that.

[Wotname]

Originally Posted by rwidman

As I read through this thread, there is some good and accurate advice, but some very, very bad advice. The problem with getting advice on web forums is that anyone can post but unless you already have a good idea, you can't easily tell the good from the bad.

[/QUOTE]

Originally Posted by Stu Jackson

Good advice, Ron. I'm sure someone will point out the incorrect ……..

Me (this time)

Originally Posted by exMaggieDrum

n.b. The reason to have a minimum of 16ga wire for power circuits is for the mechanical properties of the wire, not the electrical. So 18ga, or 20ga, or whatever may be fine for the amperage, volts, distance - it is not as strong and durable, especially after it is stripped for crimping. …….

Where did you get this gem of an idea????
If you really believe this all I can suggest is that the wiring looms are incorrectly supported.

FWIW, every commerical aircraft that you have ever been it (and almost every other one) has a squillion or more wires between 18g a and 24 ga. Their vibration and shocks load are no less than the average boat and helicopters are way worst than most boats.

[bellrock]

W3GAC, I may open a whole separate post on this, but I have a circuit breaker panel of all 15A circuits on my newly inherited 26' sailboat. I have no electric start motor, mechanical refrigeration, or anything else that requires alot of amps. Biggest draw is my searchlight at 8 amps.. everything else is lighting, electronics or a stereo. The original owner had replaced the 1970's era fuse panelboard with a west marie circuit breaker.

I like your idea of putting an in line fuse in place, say 3- amps, and using the circuit breaker as an on/off switch, as I don;t think its safe to be using only the 15 A breaker as the overcurrent protection. My question is, should the in-line fuse come AFTER the breaker panel? ( which I believe is correct). and secondly, rather than installing an in line fuse on every circuit, I'd love to use a fuse block like the bluesea system one, but can;t figure out how to make that work. Any advice? I can push this off to a new thread if its too off topic.


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[rwidman]

Originally Posted by bellrock

W3GAC, I may open a whole separate post on this, but I have a circuit breaker panel of all 15A circuits on my newly inherited 26' sailboat. I have no electric start motor, mechanical refrigeration, or anything else that requires alot of amps. Biggest draw is my searchlight at 8 amps.. everything else is lighting, electronics or a stereo. The original owner had replaced the 1970's era fuse panelboard with a west marie circuit breaker.

I like your idea of putting an in line fuse in place, say 3- amps, and using the circuit breaker as an on/off switch, as I don;t think its safe to be using only the 15 A breaker as the overcurrent protection. My question is, should the in-line fuse come AFTER the breaker panel? ( which I believe is correct). and secondly, rather than installing an in line fuse on every circuit, I'd love to use a fuse block like the bluesea system one, but can;t figure out how to make that work. Any advice? I can push this off to a new thread if its too off topic.


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You should be able to buy various sizes of circuit breakers for that panel. I replaced my 15 amp lighting circuit breakers with 5 amp breakers after measuring the actual current with all the (LED) lights turned on. It was about three amps on one circuit, less on the other.

Separate in-line fuses would be after the breaker but not necessary if you size the breaker properly.

[jheldatksuedu]

An inline fuse can be any place in the circuit as long as it is in series and do the same job of breaking the circuit to protect devices from over current. To protect against shorts to ground, it should be as close to the positive power supply as possible to protect anything after it. Often circuit breaker panels are hard wired to the single positive master breaker, thus the only reasonable place is right after the breaker, but if you can get at the connection before the individual breaker it would be OK there also and then a short in the breaker would also be protected by the fuse.

[senormechanico]

Originally Posted by funjohnson

I've had cheap, expensive, and really expensive LEDs and sensibulbs have been the worst. If I tap them just right, they finally come on, but half the time I give-up and use a different fixture. Buy the Marinebeam instead.

Whiskey Tango Foxtrot?
I've got six Sensibulbs in the saloon.
Had them for years without the slightest problem.
They've got a warranty, are RFI silent.
Check your connections.

[senormechanico]

Originally Posted by rwidman

DO NOT USE WIRE NUTS ON YOUR BOAT!!!!!!!!!!!!!

True, but it's OK to use them if you back it up by using latex house paint for top and bottom sides and linoleum for the cabin sole.

[rwidman]

Originally Posted by jheldatksuedu

............. if you can get at the connection before the individual breaker it would be OK there also and then a short in the breaker would also be protected by the fuse.

Since only the positive side of the circuit (or the "hot" conductor for AC circuits) is wired to the circuit breaker, it would be very improbable to have a "short" in the circuit breaker.

It is pointless and a source of confusion to place multiple overcurrent protection devices in a single circuit. One properly sized device located as close to the source of power as possible (such as a circuit breaker mounted in a distribution panel) is sufficient.

[jheldatksuedu]

Originally Posted by rwidman

Since only the positive side of the circuit (or the "hot" conductor for AC circuits) is wired to the circuit breaker, it would be very improbable to have a "short" in the circuit breaker.

It is pointless and a source of confusion to place multiple overcurrent protection devices in a single circuit. One properly sized device located as close to the source of power as possible (such as a circuit breaker mounted in a distribution panel) is sufficient.

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. Granted one protection device is normal, but sometimes you have 2, one fast blow high current and another slow lowwer value.

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. Not everybody has deep pockets, myself included, actually I sort of choose to be a spendthrift, it's fun and a challenge to get something for nothing

An couple interesting things concerning LEDs and cost. I have been planning on LED lighting for many years and doing my best to reduce expense. I have been obtaining cheap LED devices to modify to make inexpensive lighting for the boat. I found out the Xmas LEDs often have iron leads, that's not good, but I'm sure it's cheap and that is often what you get with produced in China stuff. Early on I made LED running lights, bright red LEDs was no problem, car stop lamps, but inexpensive green was a challenge. I found them at the local traffic department, old stop lights with too many burned out LEDs, they will most likely give you all you want. One is sufficient to make a cheap green LED running light.

Another interesting thing concerning white LEDs is the fact that LEDs are single frequency devices, monochromatic, but white is all frequencies, how do they do that? I thought about this problem when my ebay search returned 3 color LEDs that you can make many colors with, when all are on they are sort of white. But a white LED is only one device. It turns out it actually is a tiny solid state florescent light, an LED activates the phosphorus much like a normal florescent light and it produces the white light we see. Now high power LEDs are cheap enough on eBay that I can build stuff with new chips, I just bought a couple 100 watt LED chips for $5 to make a search light that should reach out 5 miles or so without a problem. Much brighter than a cars high beam headlight.

[mitiempo]

Originally Posted by rwidman

Separate in-line fuses would be after the breaker but not necessary if you size the breaker properly.

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.