No. 12 ga. be fine. The only future downside would be in using too small a wire for what you need later.

12 gauge is our standard. Just checking - I assume you're running the wire through conduit and not just laying it under the slab?

@Revolutionary Gardens

No... in fact our landscaper mentioned to us that low voltage wire is made for direct burial so no need to put it in conduit, even under the slab... should we ask him to put it in conduit then?

@Revolutionary Gardens

Great point. Btw, what's the difference between a sleeve and conduit? Any pointers for conduit material to use?

A wire runs directly through a CONDUIT that is sized for whatever wires run through it. A SLEEVE is an open-ended, much larger pipe installed under a "structure" so that later a new conduit or wire can be installed below the "structure," without cutting or tearing it up and having to repair it. Sleeves are most typically installed under walks so that later an irrigation pipe or lighting wire can be run through it ... without disturbing the walk. Lots of times walks or drives are installed before irrigation contractors begin their work.

Usually, sleeves and conduits now days are plastic. But they can be whatever the work calls for. Sleeves only need to keep a cave-in from happening, so they could be made of something "laying around" as long as it is large enough diameter and strong enough to do the job.

@Yardvaark

I see, thank you for the clarification.

you will also often see knuckle-dragging savages such as myself using the terms interchangeably :)

Hey James,

Regardless of the cable used, only anywhere from 12-15V is generally flowing; virtually harmless. The only downside would be if you had a transformer or accessory which only accepted a certain gauge of cable (thinner than a 12AWG cable). Certain voltage clamps or wire connectors can only accommodate certain wire sizes or certain combinations. King Innovation, for example, has charts for possible wire combinations for their connectors.

Hi VOLT Lighting,

I was thinking that even though the voltage is the same, heftier cables would allow for greater amps/wattage, so if I install a few too many lights and unknowingly max out the capacity of a 12AWG (or worse, a 10AWG)... and then someone accidentally damages it during gardening, it's more electricity they'd be exposing themselves to. But perhaps it's still a safe amount?

Thanks,

James