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hoskm01
12-07-2007, 12:23 PM
Hey guys,
I am not in to lighting and dont plant to be. Im usually over in the irrigation forum but have a project at home that needs some help.

Ive put in some lights in the yard, all 10w spots on trees and a couple on walls. Ive got a 300w supply and 12 guage wire. Now none of the equipment is expensive or a decent make, all Malibu from Lowes, I have no desire to blow 1000 bucks on decent material, though I know it would be better. At any rate, I have 2 12 guage strands of 100' each tied together with silicone wire nuts. 3 lights on the first strand and 4 on the second. Every light on the second strand is significantly dimmed whereas the first three are nice and bright. Ive redone the connetion numerous times between the two strands to no avail. Im only pulling 70 watts on a 300 watt supply and 12 gauge wire is pretty hefty, no? I know this is not the system of the year, but it would be nice if it would at least work correctly for a while. Figure its either bad wire or connection. Thanks for your input on possible solutions.

Lite4
12-07-2007, 01:13 PM
Your wire is fine. You are experiencing voltage drop along your wire. You need a multi-tap transformer and a voltage tester to ensure you receive the proper voltage at your lights. Everybody has to deal with this in low volt lighting. Unfortunately with Malibu, you get what you pay for and there is no remedy. Sorry

irrig8r
12-07-2007, 01:26 PM
Hey guys,
I am not in to lighting and dont plant to be. Im usually over in the irrigation forum but have a project at home that needs some help.

Ive put in some lights in the yard, all 10w spots on trees and a couple on walls. Ive got a 300w supply and 12 guage wire. Now none of the equipment is expensive or a decent make, all Malibu from Lowes, I have no desire to blow 1000 bucks on decent material, though I know it would be better. At any rate, I have 2 12 guage strands of 100' each tied together with silicone wire nuts. 3 lights on the first strand and 4 on the second. Every light on the second strand is significantly dimmed whereas the first three are nice and bright. Ive redone the connetion numerous times between the two strands to no avail. Im only pulling 70 watts on a 300 watt supply and 12 gauge wire is pretty hefty, no? I know this is not the system of the year, but it would be nice if it would at least work correctly for a while. Figure its either bad wire or connection. Thanks for your input on possible solutions.


The first thing is that my recollection is that Malibu kits come with #14 and #16 wire, not #12.

Is the dimmed run longer? Did you happen to loose a few stands when you stripped the end, thus reducing it's carrying capacity?

try some irrigation analogies:

Think of amperage as flow (current) and voltage as pressure, and voltage drop as friction loss.

Even with sufficient voltage at the transformer, any splice along the way is like adding a branch line, and any time you lose strands when making a splice is like forcing water through a reduced size coupling.

Using a heavier gauge wire might effectively increase your available "flow".

TXNSLighting
12-07-2007, 01:45 PM
you get what you pay for...

JoeyD
12-07-2007, 01:57 PM
There is no hope. Scrap the TF and buy a Unique 360 and you will be able to atleast get 12v to your first connection. Everything there after has to do with your wiring design.

irrig8r
12-07-2007, 01:58 PM
Hey guys. Matt's a good guy (with good taste in beer.) He doesn't need a lecture about his crappy lights.

He's looking for a little hand with his problem.

If you have a helpful suggestion, then pass it on, but if you just want to chime in and give him a hard time... well, I guess it reflects more on you than on him, eh?

And BTW, Matt, if you shop at Ewing and you ever want to upgrade your lights you should probably check out FX's stuff. Reasonably priced, simple and reliable.

JoeyD
12-07-2007, 02:02 PM
Not sure anyone was bashing here Gregg, more so telling it like it is. He needs a new TF for sure and he also needs to review hiw wiring design along with a volt meter to ensure proper voltage.

And yes Matt an FX TF would work just fine!

klkanders
12-07-2007, 02:09 PM
Gregg is correct! Use all the helpful stuff already stated and perhaps if you have time read as much as you can handle in the lighting forum.
By the way I have been to the New Belgium Brewery in Ft. Collins CO. Man do I love the free samples! Fat Tire Amber Ale mmm

JoeyD
12-07-2007, 02:12 PM
Funny you mention that, I have been there as well!! That was the first place I ever had Fat Tire. now I can buy it my local liquor store. I love that brew!!

hoskm01
12-07-2007, 02:27 PM
Your wire is fine. You are experiencing voltage drop along your wire. You need a multi-tap transformer and a voltage tester to ensure you receive the proper voltage at your lights. Everybody has to deal with this in low volt lighting. Unfortunately with Malibu, you get what you pay for and there is no remedy. Sorry

And a multi-tap transformer would have more than one terminal to connect to? It does have 3 terminals on the bottom. Why would it be fine in the first 3 lights and not on the next 4? The first 3 are on the first strand of 100', then the next 4 on the next strand, after the connection. the four are all equally dim. So the transformer is putting out seemingly good juice at least to the splice.

Is the dimmed run longer? Did you happen to loose a few stands when you stripped the end, thus reducing it's carrying capacity?

Using a heavier gauge wire might effectively increase your available "flow".

I redid the connection numerous times, they were all clean and consistent. Is there a better way to connect the two strands than nuts?

Can you go bigger than #12?

you get what you pay for...
Im hoping I have a connection problem, hoping for help with that, thanks though.
There is no hope. Scrap the TF and buy a Unique 360 and you will be able to atleast get 12v to your first connection. Everything there after has to do with your wiring design.

So, lets say I go buy a new transformer. Now whats the best way to splice my wires?

hoskm01
12-07-2007, 02:30 PM
Gregg is correct! Use all the helpful stuff already stated and perhaps if you have time read as much as you can handle in the lighting forum.
By the way I have been to the New Belgium Brewery in Ft. Collins CO. Man do I love the free samples! Fat Tire Amber Ale mmm

I appreciate it. I will be reading around some more; I like landscape lighting, just no motivation professionally or monetarily at my house to get into it seriously. Ill stick to pipes, heads and turf.

Funny you mention that, I have been there as well!! That was the first place I ever had Fat Tire. now I can buy it my local liquor store. I love that brew!!

They absolutely make the most delicious brews in the country. Look around if you can, they have MANY more than just Fat Tire which is a staple most places here in the west.

irrig8r
12-07-2007, 03:06 PM
Matt, reading your post again it sounds like you have two runs coming off of a single cable that then runs back to the transformer? Better if you have them run back separately in your case, or like Joey says use a higher voltage "home" run out to where you split off, with a multi-tap transformer like Unique's or FX's.

Do you have a decent multi-tester? What's the outgoing voltage at your transformer?

And "multi-tap" refers to the different taps with incrementally increasing voltage available. FX goes up to 15 V. Unique goes up to 15 or 22 V. Malibu doesn't offer such as far as I know.

INTEGRA Bespoke Lighting
12-07-2007, 04:05 PM
Bollocks to a new transformer being necessary. If the off the shelf kit transformer is 300W and delivering 12V at its secondary tap, then you can sucessufully deliver enough voltage to the fixtures in a simple system with the right wire and good connections. Its a matter of understanding and technique.

This guy is clearly looking for a simple solution to a simple system... lets not dismiss him becuase his technology and techniques are not Pro Grade.

Please contact me directly via email or phone and I will help you through this.

Have a great day.

klkanders
12-07-2007, 04:52 PM
Right On Gregg and James! Good Advice
Joey If I make it to AZ lets have a Fat Tire or two! :drinkup:

JoeyD
12-07-2007, 05:22 PM
Right On Gregg and James! Good Advice
Joey If I make it to AZ lets have a Fat Tire or two! :drinkup:


klkanders Absolutly!!



James..I would be thrilled if you could explain to us how you would prevent VD from effecting a light 100ft away and only a 12v tap. Please enlighten us??

Lets just say that Matt here on one run is using 20w lamps. He has 4 20w lamps on a 12/2 cable. 20X4=40 divided by 12 (voltage)=6.67amps

So our VD method is as follows:

Distance X 2 (AC there and back) 200ftX.00162(12/2 resistance)X Amps
200 X .00162 X 6.67 = 2.161 volts of drop.
That means it would require a 14v tap to get 12v out to his lights

Now we can do the same thing for 10/2 wire. Resistance is .00108
8/2 wire Resistance is .00064

10/2 is 1.44 Volts of Drop requires a 13v tap
8/2 is .854 Volts of Drop still would require a 13v tap.

Next you have to discuss the wiring layout. More than likely this is a daisy chain, so you will have continues drop. Light closes to TF will be burning nice and bright the lamps further down the line will still be dim.

So you can argue 8 guage wire, but at that point you may as well buy a decent TF. I dont know off hand how much 8/2 costs but it has to be well over $.60 per foot?

On top of that once you put a load on that TF that 12v tap is no longer 12v.

Now maybe I am missing something but I have a pretty hard time believeing that you can go 100ft with 4 lights with only a 12v tap and still get 12v to your lamps.

Matt, if you do want to upgrade to a new unit I would be more than happy to tell you exactly what you need to do here. But maybe James has a magic trick that will not require you to spend any more money.

Joey D.

INTEGRA Bespoke Lighting
12-07-2007, 06:04 PM
Joey, I am away from home right now in Toronto on a commercial job and thus away from my tables, resources and slide rule. But off the top of my head:

80W load on 100' of 12/2 cable = 1.0 Volts Drop giving 11volts at the LAST fixture in that scenario. Certainly above the lower limit threshold of 10.75 volts to maintaim lumen output and colour accuracy of a 12v lamp. Its not perfect, but clearly "do-able"
(Total watts on Cable x Length of run in feet / Cable Size Constant (7500 for 12/2) = VD

I have always preferred to run my lamps at between 11.2 and 11.7 volts. The output is still very good and the extra lamp life helpful.

Gregg, do you have your handy dandy NS Voltage Drop Slide Rule handy? Care to chime in?

hoskm01
12-07-2007, 06:32 PM
Thanks for the help guys.

My system is "Daisy Chained" so I dont know if that technically qualifies as a splice. Nice and easy, just two 100 foot sections tied together. The wire is #12. I would describe it as two multistranded braids wrapped individually by the plastic/rubber coating though together as one, like the picture.



http://www.calvert-wire.com/images/product_level/37.jpg

The transformer has terminals "A","B" and "C". Apparently "C" is only for a photo cell? This is the piece seen here.

http://www.malibulights.com/images/productsapp/ML300RTW.jpg

You guys totally lost me on the math/conversion nonsense, but Ill try to get out there with my meter and check it out.

hoskm01
12-07-2007, 06:34 PM
I want in on the beer, Ill bring.

JoeyD
12-07-2007, 06:36 PM
Joey, I am away from home right now in Toronto on a commercial job and thus away from my tables, resources and slide rule. But off the top of my head:

80W load on 100' of 12/2 cable = 1.0 Volts Drop giving 11volts at the LAST fixture in that scenario. Certainly above the lower limit threshold of 10.75 volts to maintaim lumen output and colour accuracy of a 12v lamp. Its not perfect, but clearly "do-able"
(Total watts on Cable x Length of run in feet / Cable Size Constant (7500 for 12/2) = VD

I have always preferred to run my lamps at between 11.2 and 11.7 volts. The output is still very good and the extra lamp life helpful.

Gregg, do you have your handy dandy NS Voltage Drop Slide Rule handy? Care to chime in?

You forgot to multiply the wire times 2. Remember we are talking alternating current, you have to meassure to the end of the run and back therfore you distance on a hundered foot run should be 200 in when measuring voltage drop. The volt meter does not lie.

But I am sure your tables may show that.

Bottom line is Matt now will make a decision to improve his lighting and that is what this is about.

Joey D.

JoeyD
12-07-2007, 06:39 PM
I want in on the beer, Ill bring.
Join the AOLP and attend the annual lighting conference. A bunch of us will be there, First round is on me!

hoskm01
12-07-2007, 07:05 PM
Join the AOLP and attend the annual lighting conference. A bunch of us will be there, First round is on me!
The Academy of Our Lady Peace?

Aggie Orientation Leader Program?


Oh, you mean the Academy of Outdoor Lighting Professionals... I should have known. Hey, look at that, they are here in Phoenix. Looks good, its nice to see some organization for different trades. Until I get into lighting professionally (at this rate for me could take a while) Ill meet up with you guys and share some beers and talk lights. Maybe down the road though, I like trade shows, especially near home! When is the next show?

irrig8r
12-07-2007, 07:15 PM
Joey, for some reason I don't think i ever got a response from you over in the Unique sponsor forum, where I asked about different methods of calculating Vd.

James seems to be using the method I learned at Nightscaping, which Nate calls Method 4 in his book.

I prefer the method I learned at a Vista seminar, because my tester shows it to be more accurate, and that (involves multiplying the length of the run x 2, as you say.

Here's what I wrote about reading Chapter 5 of Nate's book back on 10-22-07

( http://www.lawnsite.com/showthread.php?t=203374&page=2 )





Couldn't wait for the weekend, had to check out the book.

So, first thing I did when I opened it was go to Chapter 5.

Here's my take:

Method 2 seems to come close to the results that Vista comes up with.

Their formula is (L x W)x 2/ cable constant.


For instance, using the example, where Method 2 comes up with 1.62 Vd, their formula comes up with 1.6 Vd. I've tried it with different wire lengths and wattage combinations.


Their Vd numbers always come with twice the number produced by the formula I learned from Nightscaping (Method 4 in your book). Someone told me they thought the original NS formula was better applied to DC than AC, but I have no idea.


Basically, as far as I can tell, the method I learned from Vista comes close enough for planning and estimating. A multimeter finishes the job.


Next, I have to figure out what happens if I was using the hub system and all my lamps happen to burn out at once... what voltage would I have at the hub then, with no load? How about with just one or two lamps?


Are you measuring the 10.8 to 11.5 volts at the hub with no load, then adding the fixtures/ lamps?

How does that compare to NS advising greater Vd if more than half the wattage load is in the second half of the run?


And then we get to energy consumption. We can theorize, but I think the only objective way to measure is to use the same lamps/ wattage load on your system vs. their system, both as you would normally lay them out, and measure them both with Kill-A-Watt meters.

What do you think?

JoeyD
12-07-2007, 07:30 PM
I am always up for a challenge!!!!

The hub changes nothing really. The only difference with the hub is if I have 25ft of 16/2 cable on each fixture I am going to test my voltage at the hub and set it between 11.5v and 12.5v. I know I lose approx. .5v from Hub to fixture ensuring being between 11v and 12v.

Now even if I cut some of my 25ft lead off for sake of not coiling it up, I will knoe that whatever I cut off is going to put me closer to the voltage that was set at my hub. More times the not the human eye cannot tell the difference between 11v and 12v. But nothing is better than haveing equal voltage.

Now if lamps burn out then yeah you up the voltage to the remaining potentially causing a chain reaction. But if you are using a hub and 12ga cable as your norm then you will rarely have over 5 lights on a hub. So worst case scenario you lose the 5 lamps. But this can happen on a T and a Daisy Chain as well.

But the Volt Meter never lies, so lets just run a test, we have done it many time, this wont be the first time.

Joey D.

hoskm01
12-07-2007, 07:45 PM
I am always up for a challenge!!!!

The hub changes nothing really. The only difference with the hub is if I have 25ft of 16/2 cable on each fixture I am going to test my voltage at the hub and set it between 11.5v and 12.5v. I know I lose approx. .5v from Hub to fixture ensuring being between 11v and 12v.

Now even if I cut some of my 25ft lead off for sake of not coiling it up, I will knoe that whatever I cut off is going to put me closer to the voltage that was set at my hub. More times the not the human eye cannot tell the difference between 11v and 12v. But nothing is better than haveing equal voltage.

Now if lamps burn out then yeah you up the voltage to the remaining potentially causing a chain reaction. But if you are using a hub and 12ga cable as your norm then you will rarely have over 5 lights on a hub. So worst case scenario you lose the 5 lamps. But this can happen on a T and a Daisy Chain as well.

But the Volt Meter never lies, so lets just run a test, we have done it many time, this wont be the first time.

Joey D.
Im on it. .

irrig8r
12-07-2007, 07:47 PM
So if you go back to the first message it sounds like Matt says he has 2 runs of 100 ft of 12/2. One run has 30 W, the other has 40 W. That's a total of 70 W on 200 ft of cable. (As I read it, the two runs are spliced together away from the transformer somewhere, distance not made clear)

So, I would take each run, making sure I was using 12/2 and not 14/2 or whatever else Malibu sells these days, and attach them to the transformer separately, because otherwise it's 70 W over 200 ft.

Instead we have 30 W over 100 ft. where you get 2.50 A x .00162 x 200 L = 0.81 Vd
and 40 W over another 100 ft. where you get 3.34 A x .00162 R x 200 L = 1.09 Vd

These numbers are acceptable.

Using the same mathod, with 70 W on 200 ft of wire the calculation is something like this:

5.84 A x .00162 R x 400 L = 3.79 Vd.

Totally unacceptable.


So, first thing to do, in this case, is run the two lines separately from the TF.

Do you agree Joey?

Chris J
12-07-2007, 11:49 PM
Hey guys. Matt's a good guy (with good taste in beer.) He doesn't need a lecture about his crappy lights.

He's looking for a little hand with his problem.

If you have a helpful suggestion, then pass it on, but if you just want to chime in and give him a hard time... well, I guess it reflects more on you than on him, eh?

And BTW, Matt, if you shop at Ewing and you ever want to upgrade your lights you should probably check out FX's stuff. Reasonably priced, simple and reliable.

This is probably the first time I've had a problem with you, but I'm gonna speak my peace. If you're such a good friend of Matt, then you should just go ahead and do the job for him and provide him with a little knowledge. Or, you could call him directly, and tell him over the phone in 5 minutes everything you know about lighting?
The first post of this forum is for "home owners" and/or "do it yourselfers".
It is clearly explained that we professionals make our living from designing and installing quality lighinting systems. Please don't try to defend someone who is not a lighting pro that happens to wander upon this forum. We are not here to help people take business from our individual companies, nor should you. Even though this person might be a good person, or even a great friend, he is still not a lighting contractor. This forum is for lighting contractors!!
No offense, but you hit a nerve.

pete scalia
12-08-2007, 12:11 AM
This is probably the first time I've had a problem with you, but I'm gonna speak my peace. If you're such a good friend of Matt, then you should just go ahead and do the job for him and provide him with a little knowledge. Or, you could call him directly, and tell him over the phone in 5 minutes everything you know about lighting?
The first post of this forum is for "home owners" and/or "do it yourselfers".
It is clearly explained that we professionals make our living from designing and installing quality lighinting systems. Please don't try to defend someone who is not a lighting pro that happens to wander upon this forum. We are not here to help people take business from our individual companies, nor should you. Even though this person might be a good person, or even a great friend, he is still not a lighting contractor. This forum is for lighting contractors!!
No offense, but you hit a nerve.

Well said Chris.

Chris J
12-08-2007, 12:14 AM
Joey, I am away from home right now in Toronto on a commercial job and thus away from my tables, resources and slide rule. But off the top of my head:

80W load on 100' of 12/2 cable = 1.0 Volts Drop giving 11volts at the LAST fixture in that scenario. Certainly above the lower limit threshold of 10.75 volts to maintaim lumen output and colour accuracy of a 12v lamp. Its not perfect, but clearly "do-able"
(Total watts on Cable x Length of run in feet / Cable Size Constant (7500 for 12/2) = VD

I have always preferred to run my lamps at between 11.2 and 11.7 volts. The output is still very good and the extra lamp life helpful.

Gregg, do you have your handy dandy NS Voltage Drop Slide Rule handy? Care to chime in?

I probably need to keep reading to the end of this thread before chiming in, but I couldn't resist.
James, when using this formula you need to multply by 2. In other words, Cable length X Watts ; divided by the cable constant; then multiply by 2 (or at least 1.5) Unless the primary voltage in your area is excessively high, you should have been doing this all along. Do you check voltage at your fixtures after everything is hooked up? No insult intended, but I've seen similar senarios.

Chris J
12-08-2007, 12:40 AM
Joey, I am away from home right now in Toronto on a commercial job and thus away from my tables, resources and slide rule. But off the top of my head:

80W load on 100' of 12/2 cable = 1.0 Volts Drop giving 11volts at the LAST fixture in that scenario. Certainly above the lower limit threshold of 10.75 volts to maintaim lumen output and colour accuracy of a 12v lamp. Its not perfect, but clearly "do-able"
(Total watts on Cable x Length of run in feet / Cable Size Constant (7500 for 12/2) = VD

I have always preferred to run my lamps at between 11.2 and 11.7 volts. The output is still very good and the extra lamp life helpful.

Gregg, do you have your handy dandy NS Voltage Drop Slide Rule handy? Care to chime in?

No, no. This scenario dictates 2.13v of voltage drop from my calculations. Again, you are not multipying by two. Your volt meter after finalizaton will confirm your methods. You should always check the voltage at your fixtures after everything is hooked up. I'm suprised that you guys aren't doing this.

irrig8r
12-08-2007, 01:36 AM
This is probably the first time I've had a problem with you, but I'm gonna speak my peace. If you're such a good friend of Matt, then you should just go ahead and do the job for him and provide him with a little knowledge. Or, you could call him directly, and tell him over the phone in 5 minutes everything you know about lighting?
The first post of this forum is for "home owners" and/or "do it yourselfers".
It is clearly explained that we professionals make our living from designing and installing quality lighinting systems. Please don't try to defend someone who is not a lighting pro that happens to wander upon this forum. We are not here to help people take business from our individual companies, nor should you. Even though this person might be a good person, or even a great friend, he is still not a lighting contractor. This forum is for lighting contractors!!
No offense, but you hit a nerve.

Well Chris, Matt is an irrigation guy. That doesn't make him the same as a DIY in my book. You see how many posts he has? He didn't just "wander in".

I don't know him personally, just from the irrigation forum... where the guys don't take themselves quite as seriously or get into as many squabbles as seem to happen over here in lighting... I tried to explain a couple of concepts to him in terms I thought he would understand. If you have a problem with that I guess I just don't know what to say... I'm not going to apologize for it though.

Beyond that it turned into a discussion of comparing voltage drop formulas... I found that exercise kinda useful.

Cheers. :drinkup:

INTEGRA Bespoke Lighting
12-08-2007, 03:40 AM
No, no. This scenario dictates 2.13v of voltage drop from my calculations. Again, you are not multipying by two. Your volt meter after finalizaton will confirm your methods. You should always check the voltage at your fixtures after everything is hooked up. I'm suprised that you guys aren't doing this.

Gee thanks for the great tip Chris.... It never dawned on me to ever check the voltage at my fixtures.... ummm how would I do this? Should I stick the wires on my tongue to see how they taste or is there a meter or something that I could use?

OF COURSE the voltage is checked at the fixtures! 11.3 is my fav. and I take great pride at 'engineering' my circuits to deliver as close as I can get to that.

As for different voltage drop calculations and techniques, there are many different ones to choose from. The NS method has always served me well. I believe you will find that the Cable Constant they use in their method is different from the ones you use... it takes into account the AC circuit and the full run of the wire so you dont have to multiply the length by two

Have a great weekend.

hoskm01
12-08-2007, 08:39 AM
This is probably the first time I've had a problem with you, but I'm gonna speak my peace. If you're such a good friend of Matt, then you should just go ahead and do the job for him and provide him with a little knowledge. Or, you could call him directly, and tell him over the phone in 5 minutes everything you know about lighting?
The first post of this forum is for "home owners" and/or "do it yourselfers".
It is clearly explained that we professionals make our living from designing and installing quality lighinting systems. Please don't try to defend someone who is not a lighting pro that happens to wander upon this forum. We are not here to help people take business from our individual companies, nor should you. Even though this person might be a good person, or even a great friend, he is still not a lighting contractor. This forum is for lighting contractors!!
No offense, but you hit a nerve.
So then you have someone around my parts that could fix up my system for me? Why would I pay someone to come out and tell me what I could hopefully learn in this forum from people who are here to help other contractors; I'm not stupid around the house, I just dont know electrical systems like people who congregate in here. I mentioned right off the bat that I dont do lighting, dont care to do it and dont plant to get into it, but I wanted a simple and CHEAP system at my place, which I got. There is no denying I bought close to the cheapest stuff you can get (though there is cheaper). If my ignorant post is such a waste of time to you, then why spend time writing three responses? How is Gregg helping me from CA going to affect you in FL or Scalion in New York? Is your bottom line going to suffer this year because I didnt hire a real lighting contractor for my house? Gregg did help by providing a little knowledge, if you dont care to read it because you wouldnt have done the same, then get the F out of this thread.

I appreciate everyone that is willing to help and I understand my system and electrical jargon now too, especially when related to plumbing/irrigation.

Maybe you can get Sean to screen all members who want to "enter" the lighting forum to make sure they are full-fledged lighting contractors. Or you can just keep your nose up there in the clouds with only your lighting buddies. I heard stories of some people in this lighting forum, thanks for confirming it.

Pro-Scapes
12-08-2007, 08:52 AM
I take it your going for a quick easy homeowner fix.

Couple options here... I got a few transformers removed from jobs... mutitap kichler AZT transformers you can have for CHEAP... they are also 600w units so if you wanted to expand you could.

You can rewire and bring your home run into the middle of that run so you esentially have a T or you can loop it back. I doubt your getting 12v out of that box anyways. You still definatly wont be in spec but it will be more even.

Since you have no intrest in spending alot of money I would get a used multitap (ask a lighting guy in your area or im sure several here have some) or pick up a 300w new one someplace. Then run a main line to the center of your other wires or where you put a splice. Guys... he doesnt wanna mess with calculations... he is happy with the way the first run looks. He doesnt care to spend the money for pro grade installations or materials. He can make this work out. Would any of us do it like this ? prolly not but in his situation it will work.

bottom line... your transformer will keep you from obtaining desireable results. Multip tap and T is will be your easiest most cost effective fix.

hoskm01
12-08-2007, 09:43 AM
I take it your going for a quick easy homeowner fix.

Couple options here... I got a few transformers removed from jobs... mutitap kichler AZT transformers you can have for CHEAP... they are also 600w units so if you wanted to expand you could.

You can rewire and bring your home run into the middle of that run so you esentially have a T or you can loop it back. I doubt your getting 12v out of that box anyways. You still definatly wont be in spec but it will be more even.

Since you have no intrest in spending alot of money I would get a used multitap (ask a lighting guy in your area or im sure several here have some) or pick up a 300w new one someplace. Then run a main line to the center of your other wires or where you put a splice. Guys... he doesnt wanna mess with calculations... he is happy with the way the first run looks. He doesnt care to spend the money for pro grade installations or materials. He can make this work out. Would any of us do it like this ? prolly not but in his situation it will work.

bottom line... your transformer will keep you from obtaining desireable results. Multip tap and T is will be your easiest most cost effective fix.
Sweet. I like the sound of the T. If I run to a T, and each side of the T is going to remain #12, should that line to where it splits be #12, or better?

And if I could move the TF closer to the actual runs, that would help some too?

Im going to check voltage on the TF and get back to you on that Kichler. What is cheap for something like that?

JoeyD
12-08-2007, 10:43 AM
So if you go back to the first message it sounds like Matt says he has 2 runs of 100 ft of 12/2. One run has 30 W, the other has 40 W. That's a total of 70 W on 200 ft of cable. (As I read it, the two runs are spliced together away from the transformer somewhere, distance not made clear)

So, I would take each run, making sure I was using 12/2 and not 14/2 or whatever else Malibu sells these days, and attach them to the transformer separately, because otherwise it's 70 W over 200 ft.

Instead we have 30 W over 100 ft. where you get 2.50 A x .00162 x 200 L = 0.81 Vd
and 40 W over another 100 ft. where you get 3.34 A x .00162 R x 200 L = 1.09 Vd

These numbers are acceptable.

Using the same mathod, with 70 W on 200 ft of wire the calculation is something like this:

5.84 A x .00162 R x 400 L = 3.79 Vd.

Totally unacceptable.


So, first thing to do, in this case, is run the two lines separately from the TF.

Do you agree Joey?

I do agree that he should pull two home runs

JoeyD
12-08-2007, 10:46 AM
Gee thanks for the great tip Chris.... It never dawned on me to ever check the voltage at my fixtures.... ummm how would I do this? Should I stick the wires on my tongue to see how they taste or is there a meter or something that I could use?

OF COURSE the voltage is checked at the fixtures! 11.3 is my fav. and I take great pride at 'engineering' my circuits to deliver as close as I can get to that.

As for different voltage drop calculations and techniques, there are many different ones to choose from. The NS method has always served me well. I believe you will find that the Cable Constant they use in their method is different from the ones you use... it takes into account the AC circuit and the full run of the wire so you dont have to multiply the length by two

Have a great weekend.

The NS method you are using is wrong James. It was designed for DC. Nate is going to chime in on this so I will leave it up to mr VD himself. Remember we developed our entire system because of that 7500 constant method that NS was preaching even back before I was born. Nate tried it and it didnt work, Nate called Bill (this is back when Nate was a big contractor) Bill says you have a bad volt meter. Nate buys a new volt meter , same method, bad voltage. Hence the new Multi Tap and Nate digging into the electrical formula books to re discover the correct method. He didnt invent it it was always there.

ccfree
12-08-2007, 10:55 AM
Hey Joey, I did a study on the voltage drop constant method. I did the math with the exact footages of the wire and load. It is accurate to within 1/10th of a volt. I did it with the daisy chain, tee, and hub methods for wiring. The nightscaping formula works...if you times if by two.

JoeyD
12-08-2007, 11:09 AM
Hey Joey, I did a study on the voltage drop constant method. I did the math with the exact footages of the wire and load. It is accurate to within 1/10th of a volt. I did it with the daisy chain, tee, and hub methods for wiring. The nightscaping formula works...if you times if by two.


If you times by 2 it makes it much closer, yes you are absolutly correct Craig. But why not just do it the right way. Forget about cable constant. You need to times it by the wire resistance.

Nate is going to break it down on this subject sometime soon as he does in his book. (but he loves reading this forum so he would like to chime in) There are a few methods that will put you close, the method we use and a few others now use (manufacturers) is the most accurate.

It's a whole other subject to discuss now distributing that voltage. The VD formula and your TF can only ensure 12v tot he first connection. Everything there after is soley based off of wire design. T and Daisy chain have way to many rules to come out with results that just make voltage "close". Hub is the only way to distribute exact even voltage to all lamps.

Joey D.

Pro-Scapes
12-08-2007, 11:12 AM
Sweet. I like the sound of the T. If I run to a T, and each side of the T is going to remain #12, should that line to where it splits be #12, or better?

And if I could move the TF closer to the actual runs, that would help some too?

Im going to check voltage on the TF and get back to you on that Kichler. What is cheap for something like that?

Moving the trans closer would definatly help with the drop but without a multi tap your still more than likely going to have issues.

first step... get the EXACT lenghts of your runs and the voltage readings at the trans. If you have 7 fixtures and they are equally spaced I would probably bring the T in at the center fixture. Since they are only 10w and you have 12ga I doubt your drop would be noticable to the eye.

How bout some pics... this would help tremendously. Perhaps we could help you with a more effecient design. But rememeber... come spring your going to be helping me with my irrigation!

PM me about the trans I dont wanna discuss a price in public but trust me. Its a steal. Also ask your local irrigation dist about a multi tap 300w. I think I only have 5 units that are all 600w... .

hoskm01
12-08-2007, 11:33 AM
Pics, readings, drawings, all coming. Will have them up tomorrow.

Chris J
12-08-2007, 12:10 PM
Gregg / Matt:
I'll take your advise and just keep my nose out of it. Just so you will understand my position, I look at it like this: If you were a irrigation guy here in my neighborhood, and was looking for a quick lesson in lighting, I would have a real problem with these guys helping you take business from me. There are far too many non-lighting pros in my area who install lights just for the extra money. Ultimately, I end up having to fix or undo these installations because someone like yourself didn't take the time to learn enough about this trade before getting into (then out of) the business.
Sorry to step on your toes, but you don't see me over in the irrigation forum trying to learn irrigation do you? If my irrigation needs work, or if I have a customer who needs an irrigation system, I will refer them to a professional who can do the job adequately.
Have a Merry Christmas.

Chris J
12-08-2007, 12:13 PM
Gee thanks for the great tip Chris.... It never dawned on me to ever check the voltage at my fixtures.... ummm how would I do this? Should I stick the wires on my tongue to see how they taste or is there a meter or something that I could use?


Have a great weekend.

:laugh: :laugh:

Lighten up James. Sometimes I just want to have some fun.

irrig8r
12-08-2007, 01:43 PM
Gregg / Matt:
I'll take your advise and just keep my nose out of it. Just so you will understand my position, I look at it like this: If you were a irrigation guy here in my neighborhood, and was looking for a quick lesson in lighting, I would have a real problem with these guys helping you take business from me. There are far too many non-lighting pros in my area who install lights just for the extra money. Ultimately, I end up having to fix or undo these installations because someone like yourself didn't take the time to learn enough about this trade before getting into (then out of) the business.
Sorry to step on your toes, but you don't see me over in the irrigation forum trying to learn irrigation do you? If my irrigation needs work, or if I have a customer who needs an irrigation system, I will refer them to a professional who can do the job adequately.
Have a Merry Christmas.


Well, maybe the perfectly ideal solution would be for Matt to find a professional in his neighborhood and trade services... but I didn't think of it.

Happy Festivus.

hoskm01
12-08-2007, 03:13 PM
Gregg / Matt:
I'll take your advise and just keep my nose out of it. Just so you will understand my position, I look at it like this: If you were a irrigation guy here in my neighborhood, and was looking for a quick lesson in lighting, I would have a real problem with these guys helping you take business from me. There are far too many non-lighting pros in my area who install lights just for the extra money. Ultimately, I end up having to fix or undo these installations because someone like yourself didn't take the time to learn enough about this trade before getting into (then out of) the business.
Sorry to step on your toes, but you don't see me over in the irrigation forum trying to learn irrigation do you? If my irrigation needs work, or if I have a customer who needs an irrigation system, I will refer them to a professional who can do the job adequately.
Have a Merry Christmas.
I understand your concern for losing business. But... I specifically stated that I couldnt care less about doing lighting professionally here and wasnt planning to, just that I wanted a little help with my own little problem so this whole bunch of fluff could be avoided.

You are welcome in the irrigation forum anytime, as is anyone; there are many helpful folks there, including myself, and theres a warm plate of cookies on the counter, help yourself.

And I dont do half-***** jobs with materials I dont know, so no, you dont go fix jobs that "someone like myself" put in.


"Its a festivus for the rest of us!"

INTEGRA Bespoke Lighting
12-08-2007, 04:01 PM
::laugh: :laugh:

Lighten up James. Sometimes I just want to have some fun.

Chris, that was light... hence the humour I tried to insert there... My Wife says my humour is dry, so I dont blame you for not seeing my effort.

Have a great weekend.:)

Pro-Scapes
12-09-2007, 09:54 AM
I understand your concern for losing business. But... I specifically stated that I couldnt care less about doing lighting professionally here and wasnt planning to, just that I wanted a little help with my own little problem so this whole bunch of fluff could be avoided.

You are welcome in the irrigation forum anytime, as is anyone; there are many helpful folks there, including myself, and theres a warm plate of cookies on the counter, help yourself.

And I dont do half-***** jobs with materials I dont know, so no, you dont go fix jobs that "someone like myself" put in.


"Its a festivus for the rest of us!"


To chris... I seriously doubt some waterhead is gonna take away from your business by installing malibus. and he DID state he didnt want anything to do with lighting. sorry we were so eager to help someone out. I helped my local irrigation contractor figure out lighting at his house. He doesnt have time nor desire to do it and we reffer eachother for work when possible.

Chris J
12-09-2007, 10:10 AM
Again,
Sorry for getting involved. I know you "said" you had no intentions of doing lighting, but there are some that would say this just so the others would be more willing to help.
I also did not say that you installed half-***** systems. I said people like yourself (meaning irrigation contractors in general), and yes I do a lot of clean up for these folks. However, I'm not saying that all non-lighting contractors install bad systems either.
My nose is officially out of this topic. Sorry for the disruption.

Az Gardener
12-09-2007, 10:16 AM
I didn't read the whole thread so I don't know if you ever got a answer. I was dong low voltage long before multi taps and while the first lights would be brighter with higher voltage the others would still not be the same.

The fix is to put a bit more wire in the ground. Run doubles or 2 strands of 12 gauge wire to the center of the strand then the lights will have about equal voltage and the drop will be minimal because you ran more wire. Also spend a couple of bucks on pin tites for the connections.

I have had some truck issues but I would still like to get together I will be in touch. Go Cardinals!

NightScenes
12-10-2007, 03:53 PM
Do not try this at home boys and girls!! I have been busy for the past few days and so I'm quite late in chiming in here. Here is a suggestion. You MUST pay very close attention though. Use a "loop" method. Attach a wire onto the end of your daisy chain, making absolutely sure to maintain polarity. This means that you must connect the smooth wire to smooth and ribbed to ribbed. This is VERY important. Take that wire and run it back to the transformer and hook it up exactly as you did the first wire, smooth with smooth and ribbed with ribbed. Once again, this is VERY important. This way you are feeding the lights from both ends and evening out the voltage between them. They should all be about the same when you are done. If you do not maintain polarity though, "BOOM"!! The world as you know it might end. (JK) You will however burn up your transformer.

Pro-Scapes
12-10-2007, 05:26 PM
if im not mistaken he has malibu boxes... if im not mistaken or at least all the ones i have seen wont safely take 2 number 12 wires. If you do try this make sure your connections are clean and tight so that you do not burn things up. I dont think there is secondary breakers on this