# Landscape lighting transformer



## Outdoorguy (Sep 5, 2011)

I am thinking about doing some of this for my house and I haven't ever done it before. Do you have to derate the transformer by 80% since the lighting is continuous, or does that not apply for this?


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## Dennis Alwon (May 9, 2009)

I never try and fill a trany to 100% but I don't believe it is an issue. Maxunit is 300 watts, 600 or 900. Basically the 600 and 900 watt tranies are 2-300 watt or 3-300 watt tranies in one case.


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## oliquir (Jan 13, 2011)

No since fuse or breaker can be 125% of almost any transformer output


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## Outdoorguy (Sep 5, 2011)

oliquir said:


> No since fuse or breaker can be 125% of almost any transformer output


You have lost me here.


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## oliquir (Jan 13, 2011)

Outdoorguy said:


> You have lost me here.


sorry i didnt think lighting transformer has probably no fuses, i was thinking about general transformer


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## Rafverki (Jan 8, 2012)

No, the transformers come with different circuits in them, ranging from 12-15 volts, and 300-1200 watts, dc. And each transformer will have guidelines on how many lights to put on each circuit, which are at 100%. So a 300 amp transformer will let you have 15 20w 12v lights on it. 
It all depends on how many lights you install, it is best to just balance them evenly on each circuit. Each circuit is switched on the common side, not the hot. 
How many lights are you thinking of installing?


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## szhighstar (Jul 11, 2012)

for transformer design, it depends on power in the circuit and work frequency, can not overload, also can not excess, try to reach big power using smaller configuration, can you advise detail of the circuit?


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