Methods of connecting two led cabin lights to one switch

[thinwater]

I dont think he did. The manufacturer is quite specific about Vaseline and trying to read a conclusion in to what they say to suit a point of view? hmmm.

Interesting. Have you ever worked with conventional contact greases use in switch gear? It aint' like Vaseline. I did not make my statement arbitrarily or out of laziness. I have even tested greases in spray chambers.

But it is also true that there is a lot of disagreement between engineers. Is the problem arcing, heat, corrosive gases, or washout? Are we focused on high temperatures (hopefully never on a marine battery), arcing (this is a switchgear problem), corrosives, or washout (a serious concern in many marine locations, even if the problem is only condensation)? Vaseline is not very good for any of these, or generally good for most of them, so really, the only thing recommending it is convenience.

 

[thinwater]

Back to the original question. Can you put multiple wires into one crimp?

We can all agree that if there is another simple way it is probably better for several reasons. Usually there is. But most resently I was working on a project connecting LED light moduals to make emergency nav lights. Ring and terminal blocks are out. 3-4 wide Wago blocks were too bulky for the available space. I ended up soldering and heat shrinking some (3 smaller leads to one 16 awg lead) and crimping others (2x16AWG in one end, 14 AWG in the other, with heat shrink). It fit the space, is very solid, and I'm not too concerned about the ABYC thing since it is not installed.

I searched the internet and found nothing definitive, only a lot of opinions, some on each side. The only thing I could see in ABYC was a reference to connection quality, and the only likely change is a reduction in pull-out strength. I should test that. Seems to me if it meets the E-11 requirement you are in. Since crimps normally meet the UL requirement, seems likely.

BTW, Wago connectors do not pass the E-11 standard from crimps or terminal blocks (I have tested them). Just sayin'. I only use Wagos for mock-ups and applications were stain relief is certain and very nearby.

I have seen two wires in the same port of a Wago or pressure plate; both are big no-nos, since the pressure is not even and the pull-out is less than half.

Does anyone know of a code reference on this topic?

	Minimum Crimp Retention
	Tensile Strength (pounds)
				wire nut and
		crimp		pressure plate
Wire Gauge (AWG)	ABYC E-11	UL 486A		UL 486A
24	N/A	5		5
22	N/A	8		8
20	N/A	13		10
18	10	20		10
16	15	30		15
14	30	50		25
12	35	70		35
10	40	80		40

 

[Beneteau381]

Interesting. Have you ever worked with conventional contact greases use in switch gear? It aint' like Vaseline. I did not make my statement arbitrarily or out of laziness. I have even tested greases in spray chambers.

But it is also true that there is a lot of disagreement between engineers. Is the problem arcing, heat, corrosive gases, or washout? Are we focused on high temperatures (hopefully never on a marine battery), arcing (this is a switchgear problem), corrosives, or washout (a serious concern in many marine locations, even if the problem is only condensation)? Vaseline is not very good for any of these, or generally good for most of them, so really, the only thing recommending it is convenience.

we are talking about battery posts

 

[PaulRainbow]

Back to the original question. Can you put multiple wires into one crimp?

We can all agree that if there is another simple way it is probably better for several reasons. Usually there is. But most resently I was working on a project connecting LED light moduals to make emergency nav lights. Ring and terminal blocks are out. 3-4 wide Wago blocks were too bulky for the available space. I ended up soldering and heat shrinking some (3 smaller leads to one 16 awg lead) and crimping others (2x16AWG in one end, 14 AWG in the other, with heat shrink). It fit the space, is very solid, and I'm not too concerned about the ABYC thing since it is not installed.

I searched the internet and found nothing definitive, only a lot of opinions, some on each side. The only thing I could see in ABYC was a reference to connection quality, and the only likely change is a reduction in pull-out strength. I should test that. Seems to me if it meets the E-11 requirement you are in. Since crimps normally meet the UL requirement, seems likely.

I have seen two wires in the same port of a Wago or pressure plate; both are big no-nos, since the pressure is not even and the pull-out is less than half.

So, what is the difference between having 50 strands of .25mm wire or 60 strands of .25mm wire in a Wago, or any other type of connector ?

 

[PaulRainbow]

we are talking about battery posts

That's not what the OP is about. Battery posts on a boat require no grease, Vaseline or anything else, just clean and dry terminals/connections.

The Exide page says the same, but suggests Vaseline for lubrication of the clamps/connectors.

 

[thinwater]

So, what is the difference between having 50 strands of .25mm wire or 60 strands of .25mm wire in a Wago, or any other type of connector ?

Your point is unclear.

If you are referring to two wires in the same port of a Wago style spring pressure connector, this is forbidden in the instructions. Also bad under many pressure plates, although you see it all the time. Some pressure plates are designed to take one wire on each side, some are designed for a single wire. Typically this is in the manual.
a. The pull-out strength is reduced because the pressure is spread over 2 conductors. it is already on the low side, and dividing by two is not acceptable.
b. it is unlikely that two wires will share the pressure equally. Own one of the two will practically fall out. Particularly bad if they are not exactly the same size and construction.

This is why they make 3-4 port connectors. It also tolerates different wire sizes and types.

 

[thinwater]

That's not what the OP is about. Battery posts on a boat require no grease, Vaseline or anything else, just clean and dry terminals/connections.

The Exide page says the same, but suggests Vaseline for lubrication of the clamps/connectors.

Trojan says "apply a thin coat of terminal protector spray...."
Rolls says grease the terminals (manual).

There is no standard opinion. It is one of those things it does not pay to get hung up on. Clean and tight is agreed upon.

 

[Daydream believer]

The reasons are that solder is not mechanically as strong as a crimped connection, in the case of an overheat it can melt and come loose, and there is an increased risk of fatigue failure of multistrand wire where the solder finishes.

Somehow I would want the joint to fail if it got so hot that it came lose. the sooner the circuit was broken before a melt & fire the better
I hate Wago connectors waving in the breeze. I doubt that anyone would bother with the mounting clamps for them.They also take up lots of room. I cannot see why the double connector suggested in post ~35 (RS PRO Female to Male Spade Connector, Adapter, 6.35 x 0.8mm Tab Size | RS Components (rs-online.com) )which allows easy disconnection for maintenance, takes up little room, is easy for an amateur with a decent ratchet crimper, allows heat shrink insulation to cover most of the connector & provide additional support, is not the best solution.
If one needs a multiple connector then a chock block has served well for years but I do put a lightly crimped bootlace on the wire ends first & the short plastic sleeve gives a modicum of support. However. I prefer to screw the block down & cable tie the wires within a couple of inches for stability & neatness if not inside a dedicated distribution case
Paul has suggested looping the wires from one light fitting to the next. I might ask that as it is only 12V system would it not be wise to return the last one back to the supply to form a ring? Or is that never done

 

[PaulRainbow]

Your point is unclear.

If you are referring to two wires in the same port of a Wago style spring pressure connector, this is forbidden in the instructions. Also bad under many pressure plates, although you see it all the time. Some pressure plates are designed to take one wire on each side, some are designed for a single wire. Typically this is in the manual.
a. The pull-out strength is reduced because the pressure is spread over 2 conductors. it is already on the low side, and dividing by two is not acceptable.
b. it is unlikely that two wires will share the pressure equally. Own one of the two will practically fall out. Particularly bad if they are not exactly the same size and construction.

This is why they make 3-4 port connectors. It also tolerates different wire sizes and types.

I prefer not to use domestic cable on a boat.

 

[PaulRainbow]

Paul has suggested looping the wires from one light fitting to the next. I might ask that as it is only 12V system would it not be wise to return the last one back to the supply to form a ring? Or is that never done

It isn't normally done on a boat, although it would do no harm to do so.

 

[steve yates]

What does looping 2 led lights look like?

 

[PaulRainbow]

What does looping 2 led lights look like?

You run the positive and negative cables to the closest light, then from that light to the next, then to the next etc.

 

[thinwater]

It isn't normally done on a boat, although it would do no harm to do so.

The only reasons for additional pathways are amp limits and voltage drop, which are not going to be issues with LED lighting.

 

[thinwater]

Look up "piggyback spade terminals" on Google Images and see if they'll do what you need.

They come in the three sizes of blue/red/yellow crimp and Halfords, Amazon and 12voltPlanet all stock them,

Not a fan. Too much potential for exposed hot conductors unless in an area protected from inadvertent contact (inside a panel). Unless something is in a panel or junction box, in an area where nothing can touch it, there should be no exposed conductors.

I'm often amazed by the number of high-amp contactors and such installed in lockers with no gaurding over the terminals.

[BTW, the one place I would ALWAYS advise waterproof grease (No-Ox-Id is my favorite for this, but there are too many products to list and I'm mostly familiar with US brands) is this type of spade conector in a damp area. For example, the shower pump motor on my PDQ conects with exposed spades (no other option), they are the top of the motor in a bow locker, and I'm sure condensation finds them. When I got the boat the pump would not run, I cleaned and replaced them using grease, and 15 years later they are fine. I have done salt spray cabinet testing with spades, bullet contectors (common on outboards), and SAE 2- and 4-pin connectors (common on motorcycles and trainlers) with and without several types of grease. Any type of grease is better than nothing, and some are much better than others. ]

 

[PaulRainbow]

The only reasons for additional pathways are amp limits and voltage drop, which are not going to be issues with LED lighting.

Not so.

Where there are a large number of lights having supply connections at both ends of the light array means that if a connections or wire should fail, you don't lose all of the lights.

Adding additional cables for current limits is bad practice. If one wire fails the other one has to carry all of the current, which will obviously be too great for the cable (or there would not be more than one cable in the first place). Parallel cabling would need to have circuit protection to protect each cable, so if one cable failed the good cable would then be overloaded and blow it's fuse. Bad idea, better use the correct cables in the first place.

Cables are sometimes run in parallel for high current loads, such as bow thrusters, to make the cables more manageable. Fusing requirements still need to be considered.

 

[thinwater]

Not so.

Where there are a large number of lights having supply connections at both ends of the light array means that if a connections or wire should fail, you don't lose all of the lights.

Adding additional cables for current limits is bad practice. If one wire fails the other one has to carry all of the current, which will obviously be too great for the cable (or there would not be more than one cable in the first place). Parallel cabling would need to have circuit protection to protect each cable, so if one cable failed the good cable would then be overloaded and blow it's fuse. Bad idea, better use the correct cables in the first place.

Cables are sometimes run in parallel for high current loads, such as bow thrusters, to make the cables more manageable. Fusing requirements still need to be considered.

Good points. I neglected to point out what is obvious in the trade.

 

[PaulRainbow]

Good points. I neglected to point out what is obvious in the trade.

To come back to my earlier point about having 50 or 60 .25mm wires in a single crimp..... I previously suggeste it was OK to put 2 x 1.5mm cables into a blue (2.5mm) crimp. A 2.5mm cable (as used on boats) consists of 50 strands of .25 wire, whereas the pair of 1.5mm cables will consist of 2 x 30 .25 strands, so 60 .25 strands in total. I find this works well, the wires are gripped firmly, but it's best to add some heatshrink too, for some additional support. Obviously, the cables are supported by the usual, additional means.

I see from above that you've found similar practices equally acceptable, although not necessarily approved. In your example above, showing domestic type cables, i'd agree that would be bad practice, although we should certainly not be using those types of cable on a boat.

 

[thinwater]

Just for fun I did a little crimp testing.

• First, I crimped a 14 AWG wire into a 14 AWG fitting. 82 pounds pull-out against 110 pounds BS. UL min is 50 pounds.
• Then I crimped a 16 AWG in a 16AWG fitting. 58 pounds pullout against a BS of 72 pounds. UL min is 30 pounds.
• Then I crimped 2 x 16 AWG into the same size fitting and pulled just one wire. 62 pounds, against a BS of 72 pounds (the wires lost strands). UL min is 30 pounds.

Not a big sample size, but both buried the standard. Also, if the crimper is properly adjusted, in this case there was no loss in security vs. separate crimps. Crimping two wires into the same fitting, with heat shrink, seems like an acceptable practice to me. I can find no prohibition, I have seen it countless times in industry, and I don't think I can related it to more frequent failures.

For comparison, the pull-out strength is about 10x greater than a Wago, which I have also tested.

 

[Mister E]

I have some LED Strip Lights and the wire coming out of them is certainly very thin. So the manufacturer doesn't expect the load to be very high.
Not sure how ot join them to 1.5mm cable?

 

[thinwater]

I have some LED Strip Lights and the wire coming out of them is certainly very thin. So the manufacturer doesn't expect the load to be very high.
Not sure how ot join them to 1.5mm cable?

Unless you are going to do a terminal strip of some sort, which is not generally the case for something isolated like this, the conventional recommendation is a step-down crimp with heat shrink. Even if you don't need the waterproof protection, the heat shrink provides valuable supplemental support for small wires.

Some will suggest soldering. ABYC says no. Again, use heat shrink. Somewill suggest Wagos; they are not to be used outside of a box, so not IMO, unless there is a box.

If you want to know the load, it is watts/12=amps. Remember, the fuse should be sized for the smallest wire in the circuit.