Inexpensive low voltage cable lighting options????

Thanks for the input Lightwizard. Now if you dont mind, I am really going to start with the questions, I love to know everything I can about this stuff. Just to clarify, I own my apartment, so installing the transformer in the wall is not a problem for me, plus I am re-drywalling so the drywall has already been removed, and had already planned on installing a box in the wall to place the transformer inside. The apartment is in a concrete tower, so I cant easily drill into the ceiling(though it is not impossible). The lighting that I will use will utilize the MR16 bulb. The lighting is for general ambient lighting within a bedroom area [4 spots used for general lighting] (area dimensions are 7' x 14'), with a single spot illuminating some art.

If you were to ever sell the apartment, you may or may not want to leave the lighting system.

I have found several sources for proper lighting transformers (including soft start, auto reset and short circuit protection) on the internet, the primary source being WAC Lighting, do you know anything about them? There are a couple of questions that come to mind as a result of reviewing their transformers:

WAC is a major supplier although they are East Coast so I seldom use them. If you have a local retail dealer, they will have more than one source and therefore more choice.

a) What is the difference between an electronic input and magnetic input transformer? Is there a benefit to going to the extra cost of the magnetic transformer (I am installing a dimmer, so the dimmer would also be more expensive)

Answer: electronic transformers are not recommended for cable or rod lighting systems especially if they are remotely located over four feet from the end of the cable and the cable is no more than eight feet. In addition, the electronic dimmers, including the controllable X-10) are considerably more expensive -- X-10 close to $80.00. Electronic transformers can also create noise in the electrical lines so if you want to use X-10 controls, it may require a filter. I'm still not satisfied as to the reliability of electronics over 150 Watts.

b) It appears that I can use a 24v transformer on the 12v light system, is this correct? Is the extra voltage just to take care of the voltage drop over longer runs?

Yes, you can use a 24 V transformer but the 24V MR 16's are more difficult to find. It will not matter that much if your runs are only 15 feet.

c) I have to make a single run that is about 25', which includes the distance from the transformer to the canopy power connector, and then the canopy to the last light, though I could install the canopy power connector in such away that the power is connected into the middle of the wire run, effectively creating a T and limiting the max distance of the power run to about 15' - 18'. Will a 250watt 12v transformer be sufficient to run 4 - 50w spots and a 35w spot (I want to stay with 5 spots to limit the cost of the heads) or would I need to use a 300watt 12v or 300watt 24v transformer? or should I just stay with 5 - 35 watt 38degree spots and would that be sufficient to light a 7' x 14' area?

A 25 foot run would required 8 guage wire if you want as little voltage drop as possible. If you go 24 V, 12 guage would be fine.

The 250 watt would be insufficient to run the lights you are installing. Five 35 Watt MR16 would be okay -- remember that the total light output of an MR 16 Flood (for ambient light) is more than a standard lamp, in fact about double the lumens with a 60 deg. reflector.

d) The local retailer said that I could go to the maximum rated wattage of the transformer, do you recommend the 80% limit for safety concerns or to prevent the voltage drop at the last spot (if so, would utilizing a 24v transformer alleviate this concern)?

e)What would you recommend that I use as a filter (or a bulb) to prevent the harsh glare of the spots, when I am laying down in bed) [the local people seem useless when it comes to these questions.

Barn doors are the best to hide glare and are adjustable. Honeycomb or slatted (Access Lighting has bulb clip-ons of all three types) will affect the beam spread of everything but spots (10 deg). The barn doors are also the most efficient for blocking the spurious light (halo) off the MR 16 reflectors. The USHIO Eurostar reflector has the best control of the beam.

The local retailer is full of it. 80% is an electrical contractors recommendation. On 24V, you could load as high as 90%.

Oh ya, do you know of any inexpensive sources for the insulated wiring, turnbuckles, standoffs, etc. for the cable wiring system?

These have been domestically produced for years and are expensive due to low production runs and hand tooled parts. They are just barely getting these systems from import sources which should bring down the price somewhat (Taiwan has had the best factories producing high quality lighting products and Korea is getting there). There are several manufacturers but Tech Lighting is probably the most reasonable. I have used a kit from a Canadian company that is made in China but it's limited to three 20 Watt MR 16's. My installers have adapted it, by not using their low output transformer and replacing it with a 250 Watt with five 35 Watt lamps but that's about the limit at about a 15' run of cable. It is cheap, though (about $149.00 per kit including all hardware and three fixtures, the rod type with a lamp fixture at the end of the two rods).

All of this still requires screwing into the walls or ceiling so you've got no choice but to drill small holes and use screw inserts. The Intelitrax miniature track has two screws every four feet. I have that miniature track light in my own home using the more conventional looking white lamp fixtures and all 35 Watt lamps although I am lighting art and objects and not using it for ambient light. Bear in mind that lighting pictures and object does give some reflective ambient light, especially as it is nearly unavoidable not getting some of the beam reflecting off a wall. The barn doors, of course, alleviate that effect (if you want your art discretely spotted with light).

BTW, with X-10, you can remotely control an inline dimmer from any of their sending devices, like a table top for about $12.00. That eliminates trying to run the transformer to a wall switch (although my recommendation of locating the transformer near a baseboard and running the cable or wiring up the wall would allow you to plug it into a wall switch controlled outlet).

Thanks in advance for all your help, I really appreciate you input.

Have Fun

StudentOnABudget