need some advice

[vino]

Hi... I've laid out about 250 ft of 12g low voltage cable from my house to a small vineyard I have in front and down the drive way...I wanted to use 5 or 6 spot/flood lights pointed from the ground up to accent the first row of vines...the lights I bought are 50w and the transformer I have is 600W...now that I've learned about voltage drop...I was wondering what are my best options in getting this right....first off I may be able to reroute the cable and save 30 or so ft....my first light starts at about 150' down the line...would dropping the wattage of bulb make a big difference?..say 50 to 25?...would buying a larger transformer ..say a 900 w do the trick?...multi tap?...before I make any more mistakes I would like to get a sense of which direction I need to go....any help/info would greatly be appreciated...Thnx!

[sitelights]

You may get different responses to your dilemma; perhaps there are better solutions out there.

Here is the progression from easy/cheap to expensive: (1) use all 20w lamps (see "20w brighter than 50w" in the Technical Tips Forum); (2) lay out a second run of 12/2 and use both cores (600w = 2 300w cores) and divide the lamp load between each core; (3) trade in your 12v output transformer for a 12-15v multi-tap and use the tap that gives you the lamp output suitable for your purposes.

If you try these suggestions each degree of positive change should be noticeable without spending much money. (1) The reduction to 20w per fixture will increase brightness but it is doubtful that you can supply 10v to the lamps; (2) If you take half of the load off of the 20w fixtures by using both cores this simple test without adding wire will simulate using two 12/2 wire runs may give you a half a volt more at the lamps; (3) If you can upgrade to a multi-tap your problem is solved but if you have to pay for the multi-tap and will be stuck with the 12v output unit you have chosen the more expensive option.

Whatever you decide you should use both 300w cores and split the load; no point in having a core with no load. My guess is (1) will give you slightly under 10v at the first lamp and 9v at the last; (2) will result in 10.5v and 10v; (3) would allow you to chose the voltage you want and you could get 12v and 11v first to last.

These experiments require a voltage meter or a very good eye.