lighting fixtures

[jward]

i am considering using some wall mounted fixtures to permanently light my layout. i have a question concerning their ratings.

the fixtures in question say do not use more than 40 watt bulbs. would this rating be for incandescent bulbs, or for all bulbs. a 40 watt spiral fluorescant bulb has the light output of a 150 watt incandescent, would these be safe to use?

[RAM]

I would think that the 40 watt bulbs. would this rating be for incandescent bulbs.  The higher the watts the more heat that is generated.  I would think that you you would want to use a 40 watt spiral fluorescent bulb.  That would be a lot of light in one spot.

[Jim Banner]

The concern is for heat which can damage the fixture and the wiring leading to it.  A 40 watt incandescent bulb consumes 40 watts and puts out about .5 watts of light and the other 39.5 watts as heat.  A 40 watt C.F. bulb consumes 40 watts and puts out about 2.5 watts of light and 37.5 watts of heat.  So the C.F. actually puts out a bit less heat than the incandescent.

There is something else you might want to know about C.F.'s and that is the current rating versus the power rating.  A typical C.F. is rated 120 volts, 11 watts, .165 amps.  The VA or Volt-Amp rating is 120 x .165 = 19.8 watts and this is the rating to use when determining wire size.  Fortunately, your power meter measures the 11 watt rating and that is what the power company charges you for.  It is not often that this distinction between VA and watts is important but it could come up with a large, well lighted model railway.  It also illustrates the difference between volt-amps, which is the product of voltage and current, and watts, which is the product of voltage and in phase current.

Jim

[jward]

the 40 watt cfc produces about 2600 lumens of light output. they are bright, but you can take photos of your layout that look like they are taken outdoors. that much light output is also useful for laying track and finding the cause of derailments.

jim,

thanks for confirming what i thought, that the watt rating is related to heat. it is good to know that i could use say a 26 watt cfc, get the equivalent light of a 100 watt bulb, and still come nowhere near damaging the fixture.

[Mike]

Jim- What you say makes good sense. However, can you explain the warning printed on the box of my new bulbs that says not to use them in closed fixtures? Are the bulbs more sensitive to heat build up and early failure? - Mike

[Jim Banner]

Mike,
Right on.  The usual failure is in the electronic ballast in the base of the bulb, and the heat speeds up the process.

Compact Fluorescents don't much like cold either.  Somebody, in their infinite wisdom, brought the Porch Light Campaign to Saskatoon last fall.  They gave away thousands of C.F.'s.  Most people screwed them into their porch lights (no surprise there.)  A month later, they unscrewed them and tossed them out.  The lamps really hadn't failed, they just couldn't get warm enough to light up properly.  I left mine in all winter.  When it got down to 40 below, it was so dim that you could barely tell it was on, even in the dark of night.  When it warmed up again, my bulb, along with the rest of Saskatoon, was happy again and in the bulb's case, lit up again.  By late spring, it was back up to full brightness.  This winter, it will go into hibernation for six months.

The same pillars of wisdom are advocating banning incandescent bulbs in Canada.  If that comes about, we will be left with three choices for outside lighting - LED lamps, which are very expensive to buy, sodium/mercury vapour lamps, which are expensive to run because you pretty well need to leave them on all night, not just put them on when the dog goes out, or black market incandescents.  Hmmm.  Anybody know where I can get a case of PAR38's cheap?

Jim

[Mike]

Jim- Great info, as usual. Thanks!- Mike

[pdlethbridge]

 A couple of thoughts on the CFL's.  You have many choices between wattage, color temperature and color rendering index (CRI). Say your using 13 watt cfl's, they are the same as a 60 watt bulb and produce about 2700k. A 20 watt cfl (75 watt ) can be of several brightnesses. warm light (2700k), neutral white(3500k), cool white (4100k), bright white (5000k), daylight bright (6500k)
I try to get the cheapest bulb that gives me the highest k and CRI.

[rich1998]

remember, cfl's have mercury in them when trowing out the old clf's in the future.
you could consider the new led light bulbs. only about 40.00 ea when they come on the market soon.
lex

[pdlethbridge]

as compared to $3 or less for a day light CFL

[Jim Banner]

Do I detect a different interpretation of the word "only?"  Or is our friend lex of the same generation as my younger daughter, the one who thinks that the combination only $ is what you put in front of a number to make it into a price?  Personally, I would hesitate to replace all 16 bulbs around my layout with LED bulbs at a cost of "only" $640.

Jim

[mabloodhound]

Just one more point on this.   The CRI (color rendering index) is the most important factor if you're trying to get a daylight effect.   If you buy a 6500K CFI with a CRI less than 85, you will be disappointed.   Look for something higher, the more the better.   I have bought some great CFLs from www.bulbs.com.   I have no connection just a satisfied customer.

[pdlethbridge]

Same would be true if the k was lower.
I shop there for bulbs as well and I have several 6500k, cri85 bulbs in my bulb tracker. they are all under $4 each

[rich1998]

i use cfl's in table lamps and 2r3014 cfl spot lights. fourteen watt cfl's and replaces 65 watt spots. Four swivel celing lamps for pictures on walls in family room. Five spots in kitchen. the spots use to be incandescent with dimmers. took out dimmers and put in cfl's. cfl's do not like dimmers.
Picked up all cfl's at home depot
lex