# Malibu landscape lighting question



## Madman (Jan 5, 2008)

Normally, Malibu transformers put out 12 volts of AC. Would there be any reason why the landscape lights would not accept 12 volts DC? I am looking at those 600 watt Malibu transformers, but in the meantime I tried feeding the lights with a 35 amp 12 volt filtered DC power source, and it is showing a short. I have been over my wiring and cannot find any problem areas. 

It all started piecemeal when I bought one set of lights at a time and each came with an 88 watt transformer. I had five transformers feeding all of the lights. Last year, three transformers quit, and the load was too great to transfer the lights without power to the 88 watt transformers. Thats when I started messing around with the 35 amp power pack.


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## Greg Elmassian (Jan 3, 2008)

Actually, they normally put out 16v ac. The light bulbs do not care AC or DC. 

If you have a short, then there is a short. 12v * 35 amps means you have 420 watts available... why don't we do a rough calculation of the load you have? How many lamps at what wattages are you running? 

Regards, Greg


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## nkelsey (Jan 4, 2008)

Be aware that the Malibu 600wt transformers are actually two 300 watt in one box, with two sets of output terminals.....oh yeah, they hum pretty good as well.....


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## Ray Dunakin (Jan 6, 2008)

Posted By Greg Elmassian on 05/09/2009 7:23 PM
Actually, they normally put out 16v ac. 












Wait, I thought they were supposed to be 12vc ac?? In fact I was counting on that. I have 16v grain of rice bulbs, and don't want them operating at full voltage.


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## Dan Pierce (Jan 2, 2008)

To lower the voltage, just add a small resistor. A .5 ohm resistor with a 8 amp load will drop 4 volts. This will allow the bulbs to last longer. Resistor needs to be a 10 watt, and will get get very warm. 
Also, just use a very long wire (#16) to the first bulb and the long wire will drop a fair amount of voltage. 
For landscape wiring, a loss of voltage in the wire can be a good thing whereas a loss for running a train is a bad thing!!!


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## Greg Elmassian (Jan 3, 2008)

These transformers' output varies quite a bit under load. Many of them have adustable output voltage, to compensate for the load, usually different "taps" on the transformer via a slide switch. 

If you ever read a malibu lighting manual, you will see that what Dan mentioned about a long wire to the first bulb is important, because in order to have enough voltage at the "last" bulb, the voltage will be higher at the "first bulb", so extra wire length in the beginning drops the voltage enough to not burn out the first bulb. 

My technique is to use more lower wattage transformers and fewer bulbs per "wiring string" and cluster the lights close to each other on the feeder. This helps minimize variations in voltage, thus keep lights from burning out prematurely at the beginning and being real dim at the end. 

Regards, Greg


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