Custom Cable Lighting

[Guest]

I am creating a custom cable light system and have a question about what the system will support.

I will be using 20' of 16 ga. insulated wiring, anchored into wooden studs at one end and plugged into a 110v standard outlet at the other end. The wiring will be attached to insulators and drawn taught.
My question is, using 120v/50w halogen bulbs and no transformer, how do I figure out how many bulbs can be placed in this circuit before I overload it? Or how many amps will support how many of these bulbs? Thank you

[Guest]

hello, as you will be using 16ga wire it is hard to give you an answer, as over here in the uk our cable is metric and is measured in mm.

May i suggest
http://www.handymanwire.com/ubbthreads/postlist.php?Cat=&Board=UBB2

Which is an american equivilant of this site, they will be able to give you an exact answer, incidentaly each lamp will draw aproximately 2.4 amps

[cjgarlick]

Hello

As per the previous posting, it's all a question of current draw.

The formula you need is I=VA (Watts = Volts x Amps). This converts to A=I/V (Amps = Watts divided by Volts). Therefore (sorry to contradict previous post) each 50W lamp will draw 50/120 = 0.42 Amps.

Here in the UK a domestic lighting circuit would be fused at 6Amps, so you could have 14 lamps. Are you dedicating an entire consumer unit (fusebox) circuit to this lighting system, or is it part of an existing circuit? If it's an entire circuit in its own right, check the regulatory fuse rating for a domestic lighting circuit in your area, and that's what you have got to play with. If it's part of an existing circuit (much more likely I guess), you need to do some sums based on pragmatics - work out what drain the other lights are already putting on this circuit, and see what you're got left. Don't load the whole thing up to 100% of fused circuit capacity though, for obvious reasons - try to work to eg. 75%.

HTH - Kind Regards

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CJG, U.K