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View Full Version : Drawback to Installing 24v?


JimLewis
10-01-2010, 01:27 PM
Hey, so what's the drawback to installing a 24v system (e.g. Unique's new line)? I'm trying to figure out; if it's so great then why haven't we been using 24v all along?

Below is an excerpt from an email I got from Unique recently. It's something I've been considering for a long time. It does seem to make sense what they are saying. I am just trying to look at both sides of the issue before I really consider installing one.

I'm sure the idea of 24v has been discussed quite a lot here in this forum already. But I just wanted to specifically talk about the drawbacks. What are some reasons someone might not want to use 24v?

Here's the excerpt;
Have you discovered the advantages of a 24 volt system; half the voltage drop and half the amperage? This method combines design flexibility with efficiency, reduced material cost, labor reduction and energy savings.

A fact of low voltage lighting is that when you compensate for voltage drop, your power consumption increases. For instance on a 12 volt system, 100 watts of light bulb wattage at 100' on 12/2 cable will in essence pull 123 watts of electrical power. The same 100 watts on a 24 volt system will pull 106 watts! This is just wasted watts!


.

indylights
10-01-2010, 01:32 PM
I'm still mostly halogen, but with LED lamp technology, color, and selection getting better on almost a daily basis, I just don't see any reason to use a 24 volt system. If you are worried about consumption and saving watts, I would just go into an LED system.

Scott Maloney
Sunflower Landscapes

JimLewis
10-01-2010, 02:16 PM
Makes sense. And I like LED. I didn't initially but we did an LED install earlier this year with Kichler fixtures and it turned out very nice! Much better than I thought it would. I was impressed.

My only problem with LED is it just isn't there yet. Almost there. But not quite yet. A lot of the LED lamps they have out these days I don't feel are really going to last as long as they say they will due to heat. They are warrantying them for a long time. But in reality, from what I've heard and read, they go out much sooner.

My second (and bigger) problem with LED is that there just isn't very much selection right now. Even in Kichler, there are only a couple of fixtures available. And those fixtures are rather ugly IMHO. I really don't even like Kichler much anyway. I prefer solid brass fixtures like Unique. But they have nothing yet. And I also like FXL but their selection is very limited right now too and very little of it is available locally.

I'm sure there is stuff online. But I like to be able to just go to a local distributor and buy stuff. I don't like online. Last LED job we did this February, the customer liked it so much they wanted 3 more installed, immediately. I was able to go to the branch I bought them from and get 3 more installed - that day! Online I would have had to wait several days. And I can't actually see and feel stuff online.

So once companies like Unique and FXL start offering some serious selection in LED I'll probably be all over it. But for now, I'm still liking the old school halogen stuff.

So in terms of that what are the drawbacks vs. 12 volt?

irrig8r
10-01-2010, 03:09 PM
Rather than ask what the drawbacks are for 24V, I would ask if there any real advantages.

Pay more for lamps? Fewer lamps available? Are those pluses?

To me, it looks like Unique was just looking for a new arena with fewer competitors.

bcg
10-01-2010, 05:06 PM
Jim, Kichler has a solid brass version of their LED fixtures. I was like you, I thought they were ugly and wanted brass, which I thought they didn't have. Then I learned that almost all of their LED fixtures are available in a BBR (Bronzed Brass body) and remembered that you're not supposed to see the fixtures anyway. I'm doing a pretty large job right now that is almost entirely Kichler LED fixtures and I like them more and more every day. My only real complaint is the 18" lead on them (wish they came with 25') and the TERRIBLE cowl setup. They're supposed to be releasing both a snap on cowl and a new fixture with an integrated cowl very soon though.

Also, the more I've used them, the less I like LED retrofit lamps. Granted, I haven't used everyone's but what I have used seems to have a very defined cone, which has been problematic when up lighting stucco. It makes it look like someone is sitting in the bushes shining a flashlight up the wall.

NY Landscape Lighting
10-01-2010, 05:39 PM
We have used 24 volt alot the last 2 years. The main disadvantage we find is the lack of lamp beam spreads available. On occasion we wanted to use 50 watt pars and they weren't available either.

wbaptist
10-01-2010, 06:45 PM
I wont go into the sales pitch side of the things I will just share one experience I had with 24V. This week myself the GM and RMA guy went out to a local job that was close to 2.5 years old. The idea was to go out and service the job just like a contractor would. All we had was a basic as-built done by the contractor.

These are a couple things I noticed about the job.
5 840 watt transformers on the project and 150 lights.
Each transformer had no more than 4 homerun's.
I did not find a single wire over 12 amps. All homerun wire was 12/2.


We went through each transformer and tightened the lugs again,checked the sequencers and compared the loaded voltage, unloaded voltage and amperage against the original notes. The job was wired using the branch method of wiring. The wiring method made it very easy to check the voltage at each hub. All in all the 24V was very easy to work with.

This is a quick sketch I made using the a image from Google Earth and my tablet pc to create a quick sketch of the front yard.

http://i139.photobucket.com/albums/q304/rusty51501978/Nickslightingfrontyard9-30-10pdfLayedOut.jpg

lightsinchicago
10-02-2010, 11:43 AM
I just got this e-mailed to me. Seems they have another Brass LED fixture available..

http://www.vistapro.com/Files/news/Brass%20LED%20Up%20&%20Accent_09.10.pdf

Elegant Outdoor Lighting
10-02-2010, 10:45 PM
Like some others have said, some beamspreads are not available in 24v, like a MR16 20watt wide-flood... and the additional cost of lamps and fixtures and transformer.

On the up side, if I have to run lights far from the transformer, 24v saves money because I can use 12 gauge, OR if I have limited conduit for the home run wire, I can run twice the number of lights on one home-run before over-amping my wire. Remember Ohm's Law.

And another benefit of 24v, I have twice the range of acceptable voltages at the lamp. 21.6-24v vs. 10.8-12v. Again, if I have lights far away or in large groups, this really helps.

If I have one these special situations I use 24v. Otherwise I use 12v.

LEDs deserve a whole other post...

David Gretzmier
10-03-2010, 04:10 PM
If you are out of a particular 12 volt bulb, it is likely you will find an acceptable substitute locally. not so with 24v. also, you pretty much have to buy from a limited number of players a trans or bulbs. we looked at 24v a few years back, and I really did not want to have to stock both sets of bulbs. also, the LED thing could very well make you now have to have 3 sets of bulbs if you do or have done a number of systems.

we have stuck to halogen 12v thus far, tested LED randomly for the past few years, and not regretted it all.

INTEGRA Bespoke Lighting
10-03-2010, 07:57 PM
I feel there is a major drawback to using 24V outdoor lighting systems and it has nothing to do with lamps, transformers, wiring methods or performance. My issue is larger than that. My issue with 24V outdoor lighting systems is one of industry fragmentation.

For years LV outdoor lighting had a pretty bad name in the marketplace. Component quality was not all that good, contractor education was next to impossible to find, and their were no installation standards to follow. Slowly, over time, and thanks to the efforts and investments of a handful of people our industry began to get out of its rut. We are all here now in large part because this industry has fixed itself, and now we enjoy a market that turns to LV Outdoor Lighting Systems more often than not. People are used to "12 volt lighting systems".

Now along comes a major manufacturer offering 24 volt systems. For whatever reason, they begin to gain traction in the market. This only serves to fragment our industry and positions more people to once again become frustrated and dismissive of our systems and services. You see, 24V systems look exactly the same as 12V. So you install a bunch of these and all seems fine... then one day one of your clients asks their handyman/gardener/person friday to replace a few burned out lamps... The person goes down to the store and buys a bunch of 12V bulbs (full retail of course) and puts them in. The system turns on and they all burn out. How frustrating and expensive! Now how likely is it that buddy is going to think that this system, unlike all the others in the market, is running at 24V?? He isn't. He might even try a bunch of new lamps, with the same result. Now we have an annoyed and pissed off client.

The last thing that our industry needs right now is fragmentation. Instead, I feel that we should be working towards more standardization; continuing to educate the marketplace in the advantages and high quality of Low Voltage Outdoor Lighting Systems. (systems the customers can continue to call 12 volt if they wish).

That is my .02 on this topic.

P.S. In some jurisdictions you are not permitted to install any type of LV lighting system over 15Volts unless you are licensed to do so. Remember that like it or not UL1838 is the Standard for LV outdoor lighting systems / garden lighting / landscape lighting and it clearly states no power systems over 15 volts. Make sure you know what is acceptable in your jurisdiction.

RLI Electric
10-03-2010, 08:41 PM
Funny that you mention that. I had a sales rep at my place one day. He had a contractor on the phone from upstate NY who was dropping F bombs all over the place due to the fact that he got called in to service a job and it was all 24 volt equipment. He apparently didn't notice it right away but fortunately did notice it before he drove away. Needless to say, he did not have the 24 volt lamp stuff with him and had to come back yet another day.

Gr1ffin
10-04-2010, 10:50 AM
The Sony Betamax was a superior picture to VHS, but it did not make sense to buy into the Betamax when the industry went VHS.

24v is a great idea, especially for large sprawling commercial properties. It is a shame Unique did not introduce it 10 years ago.

On a slight tangent, 12 v and 1838 are so antiquated I support the mockery Unqiue makes of them (the "1838 w" trans, 24v systems, etc)

Prolightscaper
10-04-2010, 08:56 PM
What is so antiquated about UL 1838 (safety) ?

If you need more than 15 volts then you are surely doing something wrong.

I go back to the days when there were only 12 volt transformers and when you loaded them up you were lucky to have 10.5 at the transformer connection. And the connection was just that, 1 connection and it was so small you had to say a hail mary to get 1- 12 gauge wire to fit.

Mocking UL is not cool. They are their to protect you.

Bill Locklin used to say that he could burn a house down faster with 12V then he could with 120.

He also used to say that when he went to bed at night and he heard the fire sirens that he had no worries- do you?

JoeyD
10-05-2010, 02:00 PM
you could burn down a house just as fast with 12v as you could with 24v or 120v....UL1838 is and always has been a joke. People need to focus more on education and contractor liscensing then they do about 1838. If you have a clue then you can install anything without causing harm to anyone.


Good thing Auto Manufacturers dont buy into James' philosophy otherwise we would be stuck with some pretty crappy cars and engines powering them.........Every industry needs innovation, not just stagnent ideas and practicies that "work". 24v has its place in the industry as does LED.

INTEGRA Bespoke Lighting
10-05-2010, 07:44 PM
Like it or not, my scenario is going to happen. Unknowing people are going to install 12V lamps into those 24V systems and get thoroughly frustrated with "low voltage lighting systems". Their displeasure and disappointment will ultimately reverberate through the industry.

David Gretzmier
10-05-2010, 10:04 PM
perhaps a 24v trans has it's use in a 12v system for those runs where 22v won't make it.

RLDesign
10-06-2010, 11:30 AM
The Sony Betamax was a superior picture to VHS, but it did not make sense to buy into the Betamax when the industry went VHS.

24v is a great idea, especially for large sprawling commercial properties. It is a shame Unique did not introduce it 10 years ago.

On a slight tangent, 12 v and 1838 are so antiquated I support the mockery Unqiue makes of them (the "1838 w" trans, 24v systems, etc)

Hello All,

This mockery doesn't make sense to me. If you are not a licensed the electrician or do not want to work with one, then you have to follow certain codes and basic electrical requirements. Many lighting techs are still not licensed electricians. I now have to work with a licensed electrician on every job and pull an electrical permit. I personally have to install components with waterproof splices, compliant transformer and components (UL/CSA listed to spec), and have the system inspected. If you install a low-voltage system and it causes a fire, and it is not inspected - you pay the bill. If permitted and inpected, the insurance can do its job. If there are standards that are supposed to be followed and were not - I do believe a lawyer will look into some piece that was not followed. I think 12V is better for a simple reason. It is a unified standard and fits our industry better. Yes, there may be a project that requires it... but in most states you have to be a licensed electrician to install that voltage.

Talk soon.

Tanek

JimLewis
10-06-2010, 05:51 PM
Well I appreciate all the replies. Some really good thoughts here. It took a while to get some decent helpful responses to this thread but then a whole bunch of different ideas came in. I really appreciate it.

I hadn't even considered James' scenario before. Perhaps Unique should put a sticker or something in plain view right near the socket where you change the lamp. And obviously you'd want one on the outside and inside of the transformer. I think if I installed one, I'd at least put a custom sticker on the inside and outside of the transformer. If the person changing the lamps has any brains at all, they'd at least go to the transformer and check it out for a second (and unplug it) before they changed the lamps. I've been on lots of service calls and that's the first thing I look at on any old system, regardless of why they called me. So hopefully that would prevent a lot of problems.

But some other really good thoughts here. Thanks very much. A lot of things I hadn't considered before and that's what I was looking for - feedback from those who had thought it through more or had some experience installing them. Thanks!

RLDesign
10-07-2010, 09:34 AM
you could burn down a house just as fast with 12v as you could with 24v or 120v....UL1838 is and always has been a joke. People need to focus more on education and contractor liscensing then they do about 1838. If you have a clue then you can install anything without causing harm to anyone.


Good thing Auto Manufacturers dont buy into James' philosophy otherwise we would be stuck with some pretty crappy cars and engines powering them.........Every industry needs innovation, not just stagnent ideas and practicies that "work". 24v has its place in the industry as does LED.

Just curious Joey. Are the contractors you are training and licensing carrying electrical licenses? Are they being inspected? My electrical inpsector and the local inspector trainer found out I was not pulling permits. I never had for 15 years. I design solid systems. They are having a huge push in our area and state for inspections. It also says I must not just use an electrician, but be on his payroll or have his employee do the work. In 8 local municipalities, I must pull a permit and demonstrate that the components are installed correctly: correct location, height (from ground), correct plug with deep bubble cover, loaded correctly, and spliced correctly. UL1838 is what they are looking for? How does that make it a joke? I just called my inspector and electrician. If I wanted to install a 24V system in the landscape, it could not be installed in the landscaping without conduit/pipe/pvc. It has to be by an electrician. It could be installed in the landscape, but just not in the manner that the basic 12V system - more in line with 24V. I understand your point about innovation, but I feel that I would never want to mix 24V into my servicable systems. If the project arose where I would benefit from 24V, I probably would still complete with 12V. I run the the pipe and line voltage circuit, then add the additional transformer location and design the same way. I am designing more and more with LED so I am thinking in a different way on each project. Last year, I was not LED. This year I am. I will complete more projects with LED this year.

Best regards,

Tanek

Just my input. Joey, I value your opinion. I look forward to seeing your opinioin of what I am dealing with.

kelectric
10-07-2010, 09:38 PM
I use 12v or 24 volt systems for interior and exterior lighting and never had a code problem, if you follow art. 411, and chapter 3. here is part of UL1838 standard Low Voltage Landscape Lighting Systems1 Scope
1.1 The requirements in this standard apply to a low-voltage landscape lighting system and components that consist of an isolating type power unit, low voltage cable or flexible cord, and luminaires. The equipment is intended to be installed in accordance with the National Electrical Code, ANSI/NFPA 70.
In other words if you are installing equipment that is ul1838 listed you must follow that standard. It does not mean you can not install different voltage systems for lighting as long as you follow the code.

lilmarvin4064
10-07-2010, 09:47 PM
well, on a small scale, not including wire, and fixtures you could install 12 single emitter LED lights, including emitters, drivers and transformer for only $130 on a 24v system. and be dimmable.

irrig8r
10-07-2010, 10:28 PM
well, on a small scale, not including wire, and fixtures you could install 12 single emitter LED lights, including emitters, drivers and transformer for only $130 on a 24v system. and be dimmable.

Where do you find LEDs that run on 24V?

irrig8r
10-07-2010, 10:39 PM
OK...forget that question. Google shows a boatload of them, and I even found a =dimmer ( no brand name) on one website for either 12V or 24V LEDs, with a handheld remote.

I'm just used to the Vista and Kichler 12V offerings... variable inputs from 9V or 10V up to 15VAC... so who makes LED fixtures with 24V input drivers?

irrig8r
10-13-2010, 11:50 AM
Just reading Nate Mullen's blog. Check out the Oct 5 entry.

http://natetheilluminatormullen.com/

I think he's fudging (or misinterpreting) the numbers in the 15 V tap example.

He says:
105 watts / 12 volts = 8.75 amps
8.75 amps x 100 feet x 2 x .00162 = 2.83 volt drop
We need a 15 volt tap to compensate for voltage drop
15 volts x 8.75 amps = 131 watts
That is 26 wasted watts...30% in wasted watts....VERY INEFFICIENT

But wouldn't you actually be dividing 105 by 15 and not by 12?
That's 7 Amps. 7 x 15 =105... so where are the wasted Watts?

And at only 7 Amps isn't it actually more efficient than at 12V?
What am I missing here?

INTEGRA Bespoke Lighting
10-13-2010, 02:33 PM
This is splitting hairs a bit, however, it is widely known that a 12V lamp produces about 33% more light per watt consumed than a 120V lamp. So it would follow that a 12V lamp has a higher lumen per watt efficiency than a 24V lamp. Now it would not be anything to loose sleep over, but if you are going to be trying to sell something on being more electrically efficient.... Just Saying.

OR, you could stop worrying about all this entirely and just adopt the use and retrofit of LED lamps into your lighting systems, thereby achieving a 70 to 80 increase in efficiency with little to no effort.

lilmarvin4064
10-13-2010, 02:40 PM
Where do you find LEDs that run on 24V?

http://ledsupply.com/wired-buckpuck.php

http://www.dealextreme.com/details.dx/sku.13557

and there are also some line voltage LEDs, like the Seoul Acriche, that do not require a driver or a transformer.

http://www.ledsmagazine.com/news/3/11/14

NightScenes
10-26-2010, 11:01 AM
Several good points in this post. I still think that the biggest issue will end up being that as the entire planet is moving toward LED which is far more energy efficient and maintenance friendly than a 24V system. Why head in the opposite direction? There is no stopping the LED train, it's rolling faster and picking up steam every day.

I'm also afraid that the 24V system will end up meeting a lot of resistance from the electrical trade as more of it ends up in the field.

As James pointed out, the termoil from maintenance issues is going to be huge in the very near future as more and more of these systems start requiring maintenance.

wbaptist
10-26-2010, 11:11 AM
Several good points in this post. I still think that the biggest issue will end up being that as the entire planet is moving toward LED which is far more energy efficient and maintenance friendly than a 24V system. Why head in the opposite direction? There is no stopping the LED train, it's rolling faster and picking up steam every day.

I'm also afraid that the 24V system will end up meeting a lot of resistance from the electrical trade as more of it ends up in the field.

As James pointed out, the termoil from maintenance issues is going to be huge in the very near future as more and more of these systems start requiring maintenance.

The biggest supporter of 24V has been the electrical trade. The electricians like to buy our 1838watt 24v with a 240v input. 24V LED would be the best of both worlds.

NightScenes
10-26-2010, 11:36 AM
I bet they do and they'll take that to their unions and knock all of us out here out of business because it's NOT 15 volts. That was the point.