Incandescent watts vs. Cfl watts

[ritelec]

Hello all?

Quick question,

Why would a manufacturer rate a fixture with a incandescent bulb at 60w and a cfl bulb with a 23 w...

Reasoning?

 

[K8MHZ]

Hello all?

Quick question,

Why would a manufacturer rate a fixture with a incandescent bulb at 60w and a cfl bulb with a 23 w...

Reasoning?

Because of heat dissipation, I presume. The 60w incandescent limit is to keep the building from burning up, while the 23w CFL limit is likely to keep the CFL from early failure.

 

[ritelec]

Early failure, ok,
Thank You.

 

[mirawho]

The reason is actually that some CFL's have a large start-up current draw. Since the wire gauge in most small light fixtures is small, the wiring could get damaged from repeated CFL starts. Hence, the manufacturer is not taking any chances on being liable for a fire. Digi-Key had written up a good article on this very thing a couple of years back. So, any time you are replacing incandescent with CFL, de-rate the fixture for the CFL if it already wasn't suggested by the manufacturer.

 

[mirawho]

Here, I found a link to the Digi-Key article. It makes for a good read.

http://www.digikey.com/en/articles/techzone/2012/jan/compact-fluorescent-tribulations

 

[GoldDigger]

Here, I found a link to the Digi-Key article. It makes for a good read.

http://www.digikey.com/en/articles/techzone/2012/jan/compact-fluorescent-tribulations

FWIW, some (many?) CFL bulbs now do contain PF correction. Whether this also provides inrush limiting is unclear.

 

[ritelec]

Thank you !

 

[gar]

141231-1738 EST

The DigiKey article said nothing about wire, it referenced relay contact failure. No mention was made of the actual components in the experiment, or the contact material.

Silver-cadimum-oxide contacts are the type that should be used in 120 V arcing applications.
http://www.checon.com/contact-materials/silver-cadmium-oxide-sko-materials/

I believe the primary reason to limit CFL size in fixtures is bulb life as K8MHZ stated.

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