OK calling on all 12 volt geniuses

[tkwhalen]

I recently purchased from this fine site a replacement light fixture. The new fixture is LED and the old was CCF. When I pulled the old one out to install the LED I found three wires vs. my expectation of two wires (positive & negative). When I called Hunter they said the third wire is there for the dimmer switch and that I would have to remove the dimmer switch and replace it with a standard switch as part of moving to LED

Along the way I did a little experimentation. When I connect the positive to the blue wire (see picture) the fixture works just fine ... it turns off and on and dimmers like a champ. When I connect the positive to the blue with the red stripe wire the LED fixture is permanently ON .... the switch has no impact ... no on and off no dimming. OK so here a re my questions:

- Why?
----- Why are three wires needed is it dimming or the CCF or both that make it required and again why? 110 only need two for a dimmer...
------ Why is the blue with red stripe wire permanently hot it is clearly attached to the switch circuit breaker? and since the dimmer and light work with out it what is it really for and why is it there?
- I like the dimming function (and per the fixtures instructions it is dimmable) but by leaving the old hunter switch in place am I building up heat that that switch can't handle?
- I don't like having a hot wire run floating around through out my ceiling hooked to nothing but if I tape it off is there really any worry?
- My easiest path is wire the lights to the to the blue, tape off the blue with red stripe close it up and go sailing .... so what dangers/problems am I missing?


(FYI it is a dual switch the left side is a typical on and off switch connected to the red courtesy lights and the right side of the switch with the circuit board is the dimmer switch that controls the recessed lights I am replacing)

 

[Jackdaw]

The heat that a dimmer generates is a function of the current that the load (bulb) pulls through it. As LEDs draw much less than CCFs, the switch will run COOLER. The extra +12v wire in the roof will be no worse now than it has been since the boat was made.

 

[kloudie1]

Going to have to sip a rum and think about that one... until someone who knows why this is, posts.. seems strange.
I agree with Jack.. no problem.. but not what I would have expected to find there.

 

[uncledom]

Do you have the wiring diagram for your boat?

 

[Jackdaw]

LOL I skimmed of that part.

The blue wire / yellow wire PAIRS look like typical 12v parallel cabin wiring going point to point between multiple fixtures.

I would bet the the other single wire is designed to allow that one fixture to be turned on via some other control. I'm wondering is they all are like that?

 

[Meriachee]

Is this dimmer a 12v unit? Really?

 

[tkwhalen]

Folks

- I have the boats wiring diagram but it is drawn is such a way to just show connections vs. every wire in the connection.
- it is a 12 volt switch
- Jack I like your thought .. the lights are all connected in series (8 or 9 of them) they are all recessed into the main salon ceiling.... since they all come on together I assume they are all wired the same but I have not checked that ... there are not separate switches on the recessed fixtures.... however your idea makes complete sense ... it is the first explanation of many I have received that makes sense ... all that said the old fixtures have three wires despite not having a separate switch .. soooo I still wonder why?

Kevin

 

[Meriachee]

Hopefully they are all connected in parallel. If they are connected in series and one blows, they all go off.

 

[tkwhalen]

good catch ... yes I assume parallel not series ...

 

[artboas]

I recently purchased from this fine site a replacement light fixture. The new fixture is LED and the old was CCF. When I pulled the old one out to install the LED I found three wires vs. my expectation of two wires (positive & negative). When I called Hunter they said the third wire is there for the dimmer switch and that I would have to remove the dimmer switch and replace it with a standard switch as part of moving to LED

Along the way I did a little experimentation. When I connect the positive to the blue wire (see picture) the fixture works just fine ... it turns off and on and dimmers like a champ. When I connect the positive to the blue with the red stripe wire the LED fixture is permanently ON .... the switch has no impact ... no on and off no dimming. OK so here a re my questions:

- Why?
----- Why are three wires needed is it dimming or the CCF or both that make it required and again why? 110 only need two for a dimmer...
------ Why is the blue with red stripe wire permanently hot it is clearly attached to the switch circuit breaker? and since the dimmer and light work with out it what is it really for and why is it there?
- I like the dimming function (and per the fixtures instructions it is dimmable) but by leaving the old hunter switch in place am I building up heat that that switch can't handle?
- I don't like having a hot wire run floating around through out my ceiling hooked to nothing but if I tape it off is there really any worry?
- My easiest path is wire the lights to the to the blue, tape off the blue with red stripe close it up and go sailing .... so what dangers/problems am I missing?


(FYI it is a dual switch the left side is a typical on and off switch connected to the red courtesy lights and the right side of the switch with the circuit board is the dimmer switch that controls the recessed lights I am replacing)

This one is easy
The CFFL lights are PWM (pulse width modulated) dimmed lights. They are matched to the dimmer unit.
The dimmed has 3 wires
+12v
PWM dimmer signal
Ground

The CCFL fixture has a dimmer circuit in it which reads the PWM pulse train, and dims the light accordingly. But, the other wire is a switched 12v+ from the dimmer unit.
So, you can control an ordinary light from this dimmer unit by just connecting the 12v feed, and ignoring the PWM dimming control line.
The fixtures were designed so that all lights dimmed at the same rate, which is why the third wire is run common between all 3 fixtures
Btw, you can't buy these lights any more. They stopped making them. Good thing, cause the light output was awful, and they cost a fortune.
Hope this answer helps
Btw, PWM (pulse width modulation ) describes a signal which varies in duty cycle anywhere from zero to 100%.

 

[Meriachee]

As well, pwm is the only effective way to dim a led, but it would need to be properly engineered for the boat.
Probably not worth the overhead.

 

[Bill Roosa]

think dasy chain power wires. disconnect the extra wire and see what other lights don't work.
PWM is not the only way to dim leds BTW. A simple reostat (verable resistance) is all that is needed. Normally in the 470 to 10k range works for 12 volts. you would want to do some electrical engineering if you are considering this option though as to little resistance (or too much voltage) WILL fry the LED. A 0 to 10k ohm reostat with a 470 resistor in series is a good place to start if you have no idea what you are doing.

 

[tkwhalen]

OK FOLKS ...
- Now we are getting somewhere ... thank you ... artboas ... Meriachee ... Bill Roosa
- I now understand the three wire set up, what it is doing and why (a giant leap forward in my meager 12v knowledge)
My remaining questions are :
- 1- if I cut the blue with red stripe wire off the little circuit board on the back of the switch will that eliminate the hot unused wires in the headliner and still allow the new 12 volt LED's to properly operate?
-2- is it ok to use the old switch as I said above... if I connect the LED's to the blue and yellow they work fine turning on and off and dimming. or do I need to get a rheostat switch as suggested by Bill .. (which worries me since I fit his last quote of .... "if you have no idea what you are doing")

and by the way as artboas says... "Btw, you can't buy these lights any more. They stopped making them. Good thing, cause the light output was awful, and they cost a fortune." ... he is 100% correct they are terrible thus the reason for the new LED's just plugging one in feels like I'm looking at the sun vs. the old fixtures.

Again thanks for all your help and education

Kevin

 

[Bill Roosa]

well if you already have on-off-dim you would not need anthing else. If it is not broken don't fix it.

 

[artboas]

OK FOLKS ...
- Now we are getting somewhere ... thank you ... artboas ... Meriachee ... Bill Roosa
- I now understand the three wire set up, what it is doing and why (a giant leap forward in my meager 12v knowledge)
My remaining questions are :
- 1- if I cut the blue with red stripe wire off the little circuit board on the back of the switch will that eliminate the hot unused wires in the headliner and still allow the new 12 volt LED's to properly operate?
-2- is it ok to use the old switch as I said above... if I connect the LED's to the blue and yellow they work fine turning on and off and dimming. or do I need to get a rheostat switch as suggested by Bill .. (which worries me since I fit his last quote of .... "if you have no idea what you are doing")

and by the way as artboas says... "Btw, you can't buy these lights any more. They stopped making them. Good thing, cause the light output was awful, and they cost a fortune." ... he is 100% correct they are terrible thus the reason for the new LED's just plugging one in feels like I'm looking at the sun vs. the old fixtures.

Again thanks for all your help and education

Kevin

I can't believe it is actually dimming. The PWM signal is a very low current, meant only to operate the dimming controller

 

[tkwhalen]

I will check again this week and get a better picture of the switch .... but I am sure on one wire it turned on and off and dimmed and on the other wire it stay on permanently the switch had no impact

 

[tkwhalen]

Not sure why but it works as noted above ... the switch dims the LED's and turns them off and on when I connect to the solid blue wire .... and stays on permanently (switch has no effect) when connected to the blue wire with the red stripe.

 

[artboas]

Not sure why but it works as noted above ... the switch dims the LED's and turns them off and on when I connect to the solid blue wire .... and stays on permanently (switch has no effect) when connected to the blue wire with the red stripe.

Ok, I need to reiterate how this system works. By the way, the manual and wiring info for this dimmer is on the Taylorbrite site.
The original CCFL lights had 3 wires that all ran in parallel
Blue 12v+ from cabin lights feed. This also powers the dimmer.
Blue /red stripe is a PWM output from the dimmer which has variable duty cycle.
Yellow is ground.
On the original CCFL fixtures, if you didn't have a dimmer, you connected the dimmer control line to the 12v+ input. The light would turn on at (its pathetic) full intensity.
The PWM output from the dimmer is about 200 mA. It's enough current to power a led, but is not the recommended use of this output.
By connecting the blue to blue/red, you are feeding 12v+ to the light, which is why it is on full intensity.
It's not a good idea to connect the PWM output to the 12v+ line. Although it is current limited for source & sink, I think you could fry it.
To comment on my good buddy Bill R's earlier post, I think a small correction is in order.
You don't control led brightness with variable resistance. Led lights are current fed devices. So, their intensity is proportional to the current being supplied. You need to work backwards from the led specifications. A led bulb will be specified for a typical nominal operating current for its desired intensity.
At that point, you simply do an ohms law calculation taking into account the voltage rail. On board, ship's power can vary from 11 to 14 v, so a fixed resistor will not be suitable.
Many led bulbs have built in voltage regulators, and are designed to run from (nominal) 12v, or 5v. The commercial marine led bulbs usually have built in regulators.
Now, getting back to controlling your led fixtures.
There are small led driver modules available on eBay which cost less than $5. They are perfectly suited for what you are trying to do. I would mount one of these modules at each light fixture, thereby duplicating what the original Taylorbite circuitry was doing.
Here is what you want to search for on eBay:

NEW 1W LED Driver 350mA PWM Light Dimmer DC-DC Step Down Module
$2.99

Good luck

 

[RHUMB RUNNER]

I replaced the dimmer with a blue sea unit, modified the light panel with blue sea switches. Now I have a on/off switch and a momentary bright/dim switch. the Dimmer works with the LED's. I have an old post with pictures of how I modified the lights to LED"S

 

[tkwhalen]

Looked for your thread showing your installation of LED lights and a new dimmer but couldn't find it. I did find where you replaced the deck light and I was be interested in your threads on the oil pressure sending unit and the engine water pump impeller all common problems I have had. I would be very interested in understanding what you did with the interior CCF to LED conversion and how it has worked out. By the way I have the davit system if you still have question on that.