Electrician's question

How do they connect? Hard wired? Have you checked the main connection points for melting? Loose wires with incandescent bulbs can melt stuff quick.

Are they daisy chained? The ones that went out first in line? last?

Have you considered switching to LEDs?

Well, if one track went out, then another, it's probably not the dimmer.  Knowing exactly what kind of lights and tracks these are would help.

They are halogen 20W AND they ARE "daisy chained" (wired in series) so I am pursuing the "Christmas light" scenario... I'll keep all advised.

AND as I replace bulbs I'll replace w/ LED's.  The entire system has been in use for now 3 years.  (The original dimmer was replaces 8 months ago as it became inadequate when I added tracks and more heads.)  The "heads" all included bulbs, so I made a decision at the time to just postpone the LED conversion for cost reasons.  But assuming it is a burned out bulb, I'll use up all I have then go w/ LED's.

Mike- wiring in series for 120V AC is not necessary. You can feed through one track to the other but you are actually putting 120VAC to each track head. Technically its in parallel but it would appear to be series if I understand your OP correctly. If you had truly wired in series you would actually only get about 4.8 V per bulb. (120/28).

My guess is a connection is loose in one of the starter sections of the track. What size wire did you use to feed the tracks 12 ga 14 ga? I would defiantly make the switch to all LED's. Much lower wattage, and much cooler too. Just watch the color temps of the bulbs. The range from around 2700K (warm white) to over 5000K (cool white).

Most commercially available tracks are rated for 20 A 250V so I doubt its any type of overloading issue. If you make the switch to all LED change the dimmer to match the type of LED's you install. It does matter BIG TIME with LED's.

I attached the spec sheets for Cooper/ Halo track. It's the only brand I would recommend to my customers when I was in the contracting business.

Good luck,

Bob

I have long noticed that incandescent lamps dimmed by (presumably) simple dimmer circuits will show a shorter life than expected.  Not only that quite often in a pair of bulbs one bulb will burn out rather quickly.  I have noted this with a pair used outside the front door.  I have generally used 25 watt bulbs in these in recent years, and just this month I found the instructions for their timer.  (Yes, I know a timer is not a dimmer, but it is a sharkwave circuit closer.)  Use minimum of 40-watt bulbs, per these instructions, for this instance.  What do I make of this?  These are standard base 120-v bulbs.

I have a lighted overhead fan, radio remote operated; that is, it too has electronic switches.  Same problem with bulbs, noticeably short life of one bulb, although I haven't noticed it yet and it may be a couple of months already.  Possibly max wattage bulbs were used this time.

At the front door, the farther bulb on the circuit generally burns out early, IIRC.  It's obviously about ten feet further on.  As the current pulse runs down the wire, it will be reflected from the far end of the line.  This will double the cycle starting voltage at this bulb.  Remember that the sharkfin wave does not start at zero current and voltage, because solid state 5-volt devices do not begin to switch until the enabling voltage is somewhat over 4 volts.  Then how many volts to drive the power supply to a reliable 5-volts, or is that an issue on original turn-on only?

At any rate, the problem has to be that the in-rush current 120 times per second is exceeding what is expected, and I would suggest an internet search with this as a premise.   -- Frank

Investigate the rails as Bob mentioned - is there any electronics in the rails - look up the product details on the manufacturer's website

I have a commercial grade track and heads - (Cooper Lighting - Lazer Track by Halo) it is basically just two rails for AC Hot and neutral and a ground that can be passed on to the next rail.

I went from CFL spots to LED and the appropriate dimmer - a Lutron - the heads were for PAR 30 Halogen originally. Hot and wrong color.