12 volt landscape wiring diagrams ???

[James]

I have one 300 watt transformer. I want to feed 6, 50 watt bulbs.

the transformer has two outputs, to balance the load. So, I will be using (2) 150 watt outputs.

So, on each circuit, I will have 3 fixtures, each using 50 watt bulbs. What I am trying to determine is how to "balance" the fixtures. I know that the fixture nearest the transformer would have the most voltage, and those on the end, less voltage.

I want to keep the fixtures wired in parallell, so I don't want to use a loop. I "think" that I may want to use a "T" hookup, where the main feed goes out to a "T" , and the "T" feeds the three bulbs. But as I say, I don't know how to "balance" this.

Some time ago I had a good website that had some diagrams of differenct ways this can be done. I even went to the Malibu website, but could not find the info I need.

Can anyone point me to a good website for this, or offer any advice ?

Thank you very much !!

--james--

[Charles Schuler]

Some points:

1/ Loading a 300W transformer to 300W is OK, IF the transformer is of decent quality. 2/ The voltage drop can be ignored ... the fixture near or far will be close to the same voltage (unless your system uses wire that is too small). 3/ Parallel is your only choice, unless you change the voltage ratings of the loads. e.g., if the transformer secondary is 12 volts, and the bulbs are 12 volts, then all of the bulbs must be wired in parallel.

[TheBrain]

When you say "balance" the fixtures I am assuming you mean to have the same voltage at each fixture. If that is what you mean then you can do is just run two equal length wires out to the "T" and six equal length wires out from the "T"'s three off each "T". Also, you will need two "T"'s at each junction.

___________________________________ Home Improvement Forum

[Steve Barker LT]

We've found the best way to "balance" is to experiment with different wattages of bulbs. Less watt bulbs near the source and bigger watt bulbs farther away.

[Charles Schuler]

Nope. If the wires are big enough, the voltage is consistent near and far.

[James]

Thanks for the replies.

More info: The wire size is 12 gauge, and the lengths are only 50 ft each.

I will not be experimenting with bulbs..... the criteria is 6 50 watt bulbs. Three bulbs on each 150 watt tap.

Yes, I do realize that loading a 300 watt transformer rated for 300 watts is ok. Otherwise, why would it have a rating, right ?

It sounds like what you are saying is that at least on fairly short runs, the voltage drop is not that great, especially if the runs are short. Is that the consensus ??

Thanks again for all the comments. Keep them coming !!

--James--

[Steve Barker LT]

That's true, but not many people like running a 2 ga cable for low voltage lighting.

[Steve Barker LT]

So you came here for help, but don't want to try the solutions..... hmmmm

[mm]

His point was the opposite. That a low-quality transformer (or just about anything) shouldn't be run at the limit of its rating.

It has a rating partly to get people to buy it, so there is an incentive to make it sound better than it is. Sort of like AMD cpu's for home computers have higher speeds attributed to them by AMD than do Intel cpu's of the same speed. Intel sells on reputation. AMD had to have a way to compete, so it exagerates its speed. (I know they have a reasonable rationale for doing so, but the result is still that the smae speed cpu is given a higher number by AMD.) Of course there are no safety concerns.

Definitely. You could leafve coiled 50 or 100 feet of cable, and connect one end to power and another to 150 watt lightbulb, or 3 50's and use an AC voltmeter to measure the voltage on the same conductor from the one end of the 50 feet to the other, and it will be minuscule. Maybe an AC meter wouldn't do it. I'm confused. But there is some way to measure it. :)

[felderbush001]

Try this website:

has a diagram using the "T" connectors you describe.

When I did my low voltage lighting I just layed the cable and clipped on the lights making sure the first light was at least 12' from the transformer. No problems. But, I'm only using 4W bulbs.

-Felder

[James]

Thanks for ALL replies, and special thanks to Felder for the website. That was exactly what I was looking for !!

ALL other comments were helpful too !!

--James--

[George]

I don't think that analogy is reasonable. AMD CPUs actually delivered substantial gains in processing performance for equivalent clock speeds. There was no "smoke and mirrors" and you actually got the performance they advertised.

A poorly made transformer is simply a poorly made transformer. The higher rating makes it sound better but is totally meaningless.

[RickR]

Your only wiring option is 3 lamps on each tap. What you do beyond that is of little consequence. 12 gu. is quite suitable.

If you can afford the wire to make a loop, I recommend it. That will "balance" the voltage quite well. Otherwise voltage drop won't be much of a problem for you.

Richard Reid, LC

James wrote: