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higher rated fluorescent bulb in socket?



Jan 1, 1970

can I put a 60W fluorescent bulb, 120V 60Hz 14W 0.200A rated, in a 40W
rated socket.

Thanks. for your help.

Don Klipstein

Jan 1, 1970

can I put a 60W fluorescent bulb, 120V 60Hz 14W 0.200A rated, in a 40W
rated socket.

This sounds like a 14 watt compact fluorescent that is supposed to
produce as much light as a 60 watt incandescent. I am guessing that this
compact fluorescent is a spiral one.

My experience tells me that the answer is generally probably yes, it
will not overheat a fixture rated for a 40 watt incandescent.

WARRANTY: If things go wrong, I will refund what you paid me for this
advice, and that's all that I will guarantee.

As for what could go wrong:

1. If the fixture is intended for tubular incandescents, you may have a
bit of a heat problem. 40 watt 120V tubular incandescents such as
"refrigerator bulbs" have a vacuum and have little heat
conducted/convected from them. Compact fluorescents, on the other hand,
produce little infrared and have nearly all output other than visible
light in the form of conducted/convected heat.
I don't have any data handy for a 14 watt compact fluorescent, but I did
have an 8 inch globe over a socket heat up more (29 degrees C) from a 20
watt spiral compact fluorescent than from a 40 watt tubular "T10"
incandescent (19.5 degrees C). I extrapolate that a 14 watt compact
fluorescent would have caused a temperature rise 70% of that of the 20
watt compact fluorescent, or about 20 degrees C, or very slightly more
temperature rise than with a 40 watt vacuum-containing incandescent.
Probably a non-problem, but no iron-clad guarantee.

However, a 20 watt spiral compact fluorescent heated up this globe less
than a 40 watt "A19" gas-filled incandescent did (37 degree C rise).

2. In recessed ceiling fixtures, other fixtures with openings only at
the bottom, and small enclosed fixtures, heat builds up. Compact
fluorescents are more vulnerable to this than incandescents are.
In my experience, this is usually not a problem with compact
fluorescents 13 watts or less. As for higher wattages - I have noticed 15
and 20 watt (and not higher wattages) of Philips SLS being rated for use
in recessed ceiling fixtures. A majority of the time I see other screw-in
models up to about 18 watts or so in such fixtures they appear to usually
get away with this, although I have seen spiral models apparently of a
wattage in the 19-24 watt range crack in ceiling fan fixtures.
Most recessed ceiling fixtures that I see in commercial buildings with
compact fluorescent lamps have ones other than screw-in models, and the
ballasts are not in the lamp/"bulb" but somewhere in the fixture,
presumably somewhat removed from the heat. I have seen many fixtures like
that with two 13-watt or two 26-watt lamps/"bulbs".

As for lack of problems using a 14 watt spiral compact fluorescent in a
recessed ceiling fixture, other downlight, or small enclosed fixture rated
for 40 watt incandescents: I believe you should get away with this, but I
give no guarantee.

- Don Klipstein ([email protected])