Knowing the right voltage tap

[kemmer]

I was just wondering how you guys decide what tap the wire should go into. is there a way to use a volt meter or do you add up the watts and length of wire?

[cgland]

You need to either test at the fixture or at your hub. 10.8-12.0 is ideal

[danf]

Best guess to start, then check with a multi-meter and adjust as needed.

Even though it's low voltage, a multi-meter needs to be set on the "AC" setting when testing LV lights.

[Evening Star Lighting]

Unique Lighting makes a slide ruler that will determine the correct voltage tap. It works off calculations on wire gauge, length of the run, and wattage used. Check your local Unique dealer, they're free.

[CaptainsLS]

If it catches on fire... you need to decrease it.

But seriously, a multimeter specific to LV lighting is a standard item and they only cost about $40. All of the lights I have used have a spec sheet in the package telling what will ensure the longest lifespan for the fixture.

[NCSULandscaper]

use this calculator

http://www.cast-lighting.com/calculator/volt-calc.html

[CaptainsLS]

Thanks for that link! Thats a nice calc to have handy.