Simple wiring question, I'm 99 44/100ths % sure I'm right, but I have to ask

Oh, yeah. I know all about double insulation. I don't like being shocked. At all. :-) ALL wires are routed through appropriate loom/ conduit and secured tightly, and whenever it passes through a metal hole, rubber grommets will be used. All final terminations are at an standard junction box. I'll put a 5A fuse in the box for good measure. By my math, this should present a total load of 440 watts equaling 3.82 amps).

The lights are only going to be used for a maximum of 10-15 minutes at a time, with 30 minutes to an hour rest between cycles. And they will only be used like that about once a month.

I was also thinking about making a 'burn out' indicator out by paralleling a 1156 bulb (21 watts) at each fog lamp. That way, if one goes out, it will probably take the 1156 with it, and it will be obvious which one died. Or I might get lucky and catch it before the indicator dies, a distinct possibility!

I was going to use 12 gauge wire, but now I am thinking of going to 16 or even 18 gauge to further increase the resistance. The total wire run will be about 70'. You think that will be OK, or should I stick to the 12?

I want to thank everyone who responded to my original post. All input is very appreciated, and will be put to good use!

We used high pressure sodium for color matching with good results.

You can buy 12 V 50 W tungsten halides with reflector at the dollar store. You could try matching them for use in series strings, however if one burns out you will apply 115 VAC across that lamp and they may arc over since they are not designed for this service.

the

true fog lamp.

I guess the fog lamps on any of my cars haven't been true. Fog lamps simply are mounted lower so they don't reflect off the fog directly back. They're usually pointed more down so they illuminate the road directly in front.

coverage is bigger.

High beams are simply pointed straight forward.

Not here. Low beams are simply pointed down and to the right so they aren't in the opposing driver's eyes.

Never had one fail.

system. Think

That's why I have two. ;-)

The series Xmas bulb strings have an internal structure that will short the bulb when the filament burns out, allowing the string to stay alive.

What will probably happen is one light will be lower resistance than the rest and take a lot of current and blow itself up as it lights first and the others remain almost a short circuit.

I know they do this with xmas tree lights but they are usually run well below 12 volts each.

They are in series, so current-hogging shouldn't be a problem.

The line is rarely 115VAC, more like 125VAC, which would mean 125/8=15.6 per bulb, and if truly incandescent rated at 14V nominal would make for a (14/15.6)^12= 73% reduction in operating life. Anyone have a problem with this? The method I have seen used, and probably mandated by code, is to install a stepdown transformer at each lamp, lamps wired in parallel off main branch, you only need a 60VA or so which is not too big, but there goes the budget. There may also be a fire safety issue with applying the full line across a failed lamp which is not designed to hold it off predictably.

mount them out of reach, and on an insulating surface (because they won't have insulation rated for mains) affix "live wires" warning labels. after all that there's still an electrocution risk when one of the bulbs blows and someone who doesn't understand what you've done tries to replace it.

The safe way to power them would be from a 12V or 24V transformer.

Code MAY require a certain maximum VA transformer - watch that one.

It's a factor of 15 or 16 higher at operating temperature.

Mark