Light fixture ratings for CFL vs incandescent

[JHZR2]

Hi, One of my outdoor lights went bad sometime back and so Im replacing it. A curious thing I noticed in the manual is that there is a different rating for CFLs and regular lights. It is just a normal type a bulb socket motion sensor lamp. The specs rate it for 150W bulbs, but only for 30W self balasted CFLs. Any idea why? I would have thought that one could fit a KILLER CFL in there (if they existed) since 150W is 150W, right? I cant imagine that power factor is a consideration in a relay operated light fixture... I have seen this elsewhere too. Far lower ratings on CFLs in a socket than an equivalent incandescent or halogen bulb. Any idea why? Does it have to do with how local to the actual lamp fixture the heat generation is, or something like that? Thanks!

 

[eljefino]

I like that they admit that you could use one of any size at all.

 

[dparm]

Don't the CFLs have massive inrush current? Maybe that's the reason -- would blow a fuse or damage the housing.

 

[JHZR2]

Originally Posted By: dparm

Don't the CFLs have massive inrush current? Maybe that's the reason -- would blow a fuse or damage the housing.

Could be, but that much higher than, say, my in sink food disposal or refrigerator, on their respective 15A circuits? and I would doubt that the inrush would be much more than 5:1, if it was that, then the current would be the same as the rating for the incandescent anyway... Of course there is a dI/dt factor, but these levels of inrush Id imagine are still relatively small for a breaker, it is only a 30W steady-state load, max for CFL.

 

[johnnydc]

I was wondering the same thing about these bulbs. Here is a link I hope will help you. Seems to make sense, I would think you can use 150w cfl since it only uses about 40watts or so. http://www.bulbamerica.com/wattage-lumens-brightness.html

 

[DBMaster]

CFL's end up having very short lifespans in applications where they are on for less than fifteen minutes at a time. Unless the light is going to on for the whole night I wouldn't advise using one for a motion detector activated lamp. I have a motion detector floodlight next to my garage door. It uses a 150 Watt halogen tube bulb. So far, it has lasted in excess of ten years. I tried replacing the bulbs in my mast bath with decorative (flame shaped) CFL's. Because they were only on for short bursts they were lasting only a few months.

 

[dparm]

Good point, DBMaster. If you want to be more energy efficient, you could jam an LED bulb in there.

 

[SwampSurvivor]

Also, if it gets cold where you are (doubt it in New Jersey), they are EXTREMELY DIM. My parents have one in their kitchen and porch and , on the cold nights there's almost no light

 

[JHZR2]

Originally Posted By: dparm

Good point, DBMaster. If you want to be more energy efficient, you could jam an LED bulb in there.

This was my initial intent, but at $42 each it isnt cost effective. I have some CFLs in a switched outdoor fixture that Im very happy with. When cold they are purple for a bit, but it is not a big deal for that application which is long-term on when we are using it. Id imagine that LEDs will suffer the same short life if used in a short on-off cycle, same as CFLs?

 

[johnnydc]

I have them outside and it gets cold here. It takes a couple minutes for the to warm up.

 

[NateDN10]

Originally Posted By: JHZR2

Originally Posted By: dparm

Good point, DBMaster. If you want to be more energy efficient, you could jam an LED bulb in there.

Id imagine that LEDs will suffer the same short life if used in a short on-off cycle, same as CFLs?

Nope. LEDs are quite happy with being rapidly cycled on and off. After all, they are use in indicator lights on hard drives and routers where they happily blink for years and years.

 

[ARCOgraphite]

Maybe if the CFL bulb is in an enclosed fixture the ballast/xformer would overheat and toast. FL are high voltage DC not AC. Had a few of these chinese things in open in-home fixtures smoke and burn up after a couple years in service. Dangerous things.

 

[edwardh1]

where will we invest all the savings? the box says we save 100s on each bulb . mine dont last

 

[DBMaster]

I have been getting LED bulbs, on occasion, through eBay and a website called tmart.com. I recently got a PAR38 indoor flood on eBay for $18.99. It is equivalent to a 65 or 75 Watt incandescent - based upon the number of lumens claimed. I buy CFL's and LED's based upon lumens and if the product does not state the light ouput I don't buy it. I tried a few of those $6 ones from Wal Mart a few years ago and found them wanting. They didn't last very long and were quite dim. The newer ones they are selling use CREE LED's so they may be brighter, but the outputs still don't compare. You want to make sure that whatever fixture you use them in comes up to full voltage immediately. LED bulbs, unless they are "dimmable," will flash if they are operated below a certain voltage threshold. I use, as a general rule, around 450 lumens when replacing a 40 Watt incandescent, and 800-1,000 when replacing a 60 Watt. You can easily find those numbers online, though. Lots of cheap LED bulbs out there that won't make you happy.

 

[sparky123]

CFL's bulbs do not like to be cycled off/on. Will shorthen their lifespan as mentioned above. For an outdoor flood fixture I would use a regular Par 38 incand. bulb. (Especially is it is a "Dual-Bright" type.) Also, if the fixture has a metal shroud around the bulb, the cfl's w/their large base will not fit. HD has a 6pk of Par 38 bulbs where I live for $17. LED fixtures are the wave of the future. CFL's are a stop-gap measure, imo. Back to the original question, you have realize CFL's still generate quite alot of heat. Just because a socket is rated for 60w incand. does not mean you could use 100w 23W CFL bulb. They want you to use the same size bulb. 60w incand = 14w cfl bulb in size. The PAR 38's do come in different wattages and same size bulb though.

 

[sparky123]

LED and CFL bulbs can only be dimmed if the package says "dimmable." Also, dimmable CFL/LED bulbs require a special dimmer. The dimmer has to say for use w/cfl and led bulbs. Starts out about $20 for the dimmer. (The least expensive reg. incand. sinple-pole 600w dimmer is about $5.)

 

[justinf89]

I too bought a fixture like this and don't know. I just wanted to show you this beauty. They have them locally where I live and I've always wanted one. It's bigger than my head. http://m.homedepot.com/p/TCP-68-Watt-300W-Soft-White-CFL-Light-Bulb-DISCONTINUED-28968RP/100676712/

 

[Voltmaster]

CFL dont require anything special just use regular ones.

 

[HerrStig]

As usual, the enviroweenies jumped into this without thinking it through, and banned (how they LOVE to ban things, knowing SO much more than the rest of us) instead of letting the MARKET work it out. LED's will come down in price, forcing folks to buy these Hg containing CFLs was, as usual, more driven by special interests than anything wlse. THey sell TONS of Chevy Volts that way, too.

 

[DBMaster]

I agree. Market forces seemed to work very well in bringing down the price of CFL's without intervention. I got an "awesome" deal on a CFL replacement for 60W bulb in 1993 - $10. Now, you can buy a multi-pack of name brand CFL's for that price and there are a wide variety of shapes and color temps available. LED's are already coming down in price, too. There are still uses for incandescent bulbs as well. There are many lights in an average house that are only used intermittently, for seconds at a time. CFL's are not appropriate for those uses and LED's are still far too expensive to realize any efficiencies.