24VDC lighting systems?

[treez]

Hello,

I would like to investigate the different 24VDC LED lighting distribution systems that are currently available on the market as we have to plan a large office building lighting system.

I simply cannot find the offerings which i know must be out there in this field. I wish to compare prices

Do you know of any 24VDC lighting systems.

Eg, Mains to the building, then power converter, then 24VDC distribution wires to the separate lamps.

Clearly its more efficient to do PFC in a centralised unit placed eg in the basement of the building, and then distribute DC to lamps from this point. Theres also the advantage of easy interconnection with solar power.
Obviously one cannot use >24V as it creates too much contact sparking in connectors which wears them out unless they are very expensively made.

 

[tpetar]

In 24V system you can use two 12V in serie like on this illustration :



You will have smaller wire, less voltage drop for a length of wire, less power loss,....



Best regards,
Peter

 

[prashanttyagi85]

why are u going for 24v dc
as in market there are so many led drivers available

 

[treez]

why are u going for 24v dc

24vdc used because there are lots of available switches that can switch 24vdc without sparking. We have a power hub near each cluster of 24vdc lamps and simply run cable to the lamps.
The power hub converts mains to 24vdc with PFC.

Running mains to each lamp fixture is more inefficient as each fixture needs its own pfc and its too expensive to do full pfc in each lamp so its about 85% pfc which is giving inefficiencies in the supply network.

 

[chuckey]

As each LED has a rectifier feeding a reservoir capacitor, I would guess that the load PF will be capacitive. When one light is on the chances are that they are all on as its nightime, so why not go for PFC correction on every floor or deptment, just find your mains rated inductor!!
The best way would be to use individual LEDs in a reflector all rated at the same current and have a centralized current source. To turn a LED off your switch simply shorts it out. So you literally have one PSU and a couple of LED dies in every lamp. Using 24V means that every lamp must have its own internal inverter, so this would decrease the reliability. You could affors two current sources so you have 100% backup in case one fails.
Frank
Frank

 

[treez]

Sorry but i think 24VDC "track" lighting systems are the way forward due to their cheaper cost.
?
Is the following 24VDC "track" lighting system amenable to be used as a general offcie lighting system?.....or for lighting up a supermarket such as Wal-Mart or Tesco, say?

JLS2.1 24VDC track lighting system.
**broken link removed**

It looks great but i cant tell if it would be powerful enough to do general office, or supermarket lighting?
On the website it looks like the JLS2.1 system may only be for Aesthetic lighting or "mood" lighting?

 

[kam1787]

I would like to investigate the different 24VDC LED lighting distribution systems that are currently available on the market as we have to plan a large office building lighting system.

Most 24VDC LED lights are 'strips' which could be housed in a FL conventional fixture.

As for a complete LED light most are 12VDC or 120VAC or 220VAC. A manufacturer could be called upon to offer a 24VDC version.

As well there are flood lighting systems which natively run off 48VDC and higher. However these are not suitable for an office.

Eg, Mains to the building, then power converter, then 24VDC distribution wires to the separate lamps.
Clearly its more efficient to do PFC in a centralised unit placed eg in the basement of the building, and then distribute DC to lamps from this point.

I suggest it depends on several factors, especially for a retro-fit. It might be more efficient to have a central point (but then you also have a single point of failure which is not a great idea] but it may not be economical nor advisable.

I suggest having an electrical engineer do a complete study before committing further resources.

No-one that I know of has done as you intend.

 

[treez]

No-one that I know of has done as you intend.

do you know what the reasons for this are?...as such, why not use the JLS2.1 system for general office lighting.?

 

[kam1787]

do you know what the reasons for this are?...as such, why not use the JLS2.1 system for general office lighting.?

Is JLS2.1 in common use? Is it a standard? Looks to me like a brand name for a product set which is not very innovative. The material on JLS2.1 is full of marketing hyperbole, with little substance.

Reasons? Perhaps the following;

- cost

- non-standard

- single supplier

- weak range of lighting fixtures

- cost of retro-fit

- incompatible with existing standards

 

[treez]

"1850 lumens per linear meter" sounds good enough to me.
Juice can sell the led fixtures that go with it....

Surely this can be used in office lighting....standards?......its 24VDC, its well below the shock hazard...standards not needed.

 

[kam1787]

"1850 lumens per linear meter"

can you give the link for that?

- - - Updated - - -

...standards not needed.

It is not a standard lighting system, nor a standard voltage, nor standard connectors[that I saw], nor..................

You are putting the office lighting system at the mercy of a single supplier - is that wise?

 

[treez]

can you give the link for that?

you can get to it either in the link i gave above, or a link off from it....it is there.

 

[kam1787]

you can get to it either in the link i gave above, or a link off from it....it is there.

I did look and look and look but never found the figure you mentioned. The lumens stated on the pages I read were far lower.

If there is a link to another website, I suggest it is common courtesy to provide it.


Did you find the 24VDC LED strips that I mentioned?