Is a 60W bulb in a 100W socket safe?

[Engineer]

Originally posted by: Spencer278


It isn't really that simple because your light bulb isn't purely resistive and your using AC current.

You would probably have a very small Inductance in there and likely, little or no capacitance (at least that is what I would imagine a "wound" filament (springy) would introduce (sorta like a minature choke). Also, the equation: Power = I^2*R = V*I would hold true (for the most part other than the small inductance factor) if the current and voltage were RMS numbers for AC, which is what the voltage is (120v).

Hell, if the inductance is small enough, it should be almost like a DC calculation, shouldn't it? (I forgot all that crap a little while ago! )

 

[Atheus]

Originally posted by: Legend

It isn't really that simple because your light bulb isn't purely resistive and your using AC current.

Ok, that makes more sense.

uh, if R is variable, then i doesnt have to change

If R is fixed then i will change depending on voltage or power.

Both bulbs are 120 V. Voltage is constant. I was assuming that resistance was purely changing the power and current was constant. With that in mind, V=I*R would not make sense because R changes while I and V remain constant.

Resistance is 'resistance to current flow' and so determines I when voltage is constant.

In math:

120 = 5 * x
120 = 5 * y

y cannot equal x

Not sure what you are trying to say, but x does = y there...

 

[granolagirl]

Isn't what OP wants to do essentially what we all do when we replace an incandescent light bulb with a lower wattage compact fluorescent light bulb?

Sounds safe to me

 

[Howard]

Originally posted by: Black88GTA

Originally posted by: Anubis

Originally posted by: Legend
So there's no such thing as a 100 W socket? The power applied is variable?

sre you talking about a normal light socket?

because they cna take ANY light bulb from say 15w to 1000w

But the wires used to construct the fixture may only be rated to a certain wattage. If a bulb draws 500 watts, and the wires are rated to 100 watts - you're gonna have a fire.

As Engineer said, 60w bulbs in a socket rated at 100 will be fine, as long as voltage is the same.

Wires rated only to .8A?

 

[Wonderful Pork]

Originally posted by: Legend

It isn't really that simple because your light bulb isn't purely resistive and your using AC current.

Ok, that makes more sense.

uh, if R is variable, then i doesnt have to change

If R is fixed then i will change depending on voltage or power.

Both bulbs are 120 V. Voltage is constant. I was assuming that resistance was purely changing the power and current was constant. With that in mind, V=I*R would not make sense because R changes while I and V remain constant.

In math:

120 = 5 * x
120 = 5 * y

y cannot equal x

thus the equations are false

voltage may be constant (that being the output from the wall socket), however the POWER is not the same. Therefore it would be easier to say

60W = i^2*x
100W = i^2*y

so for i constant x =/= y, however V and R are variables. For the 100W and 60W bulb, BOTH i and R are variables since the voltage from the wall is a constant 110V AC

 

[HonkeyDonk]

How did this thread go from answering a simple question to going in circuit analysis and explanations?

And you're a CE major? oh dear god...you're in the wrong frickin' major buddy.

 

[Legend]

How did this thread go from answering a simple question to going in circuit analysis and explanations?

Because I explained the reason why I didn't understand the question, despite being an engineer, was the relationship between voltage, current, and resistance with different power rated light bulbs.

And you're a CE major? oh dear god...you're in the wrong frickin' major buddy.

So far in computer engineering I've learned, after the general education crap, about Power PC assembly, C, C++, matlab, signals and systems, basic circuit analysis, and digital logic. Not much hardware design, or at least yet.

Nothing ever taught me the application of circuit design to light bulb application. I apologize.

And from co-oping in the field I know that engineers should ask questions when they don't understand something basic, not spend somewhere like an hour on google trying to figure something out on their own that could be answered by someone else in 2 seconds.

 

[Legend]

Not sure what you are trying to say, but x does = y there...

I was saying that because I assumed voltage and current to be static, and x being the resistance of one light bulb and y being the R of another bulb with a different power rating (thus x is not y), the equations did not make sense to me. The could not be equal. Obviously that assumption was wrong.

When I said x cannot be y, that was a premise. Then the conclusion was the the previous listed equations were false.

Resistance is 'resistance to current flow' and so determines I when voltage is constant.

Yeah, that's the fundamental principle that I was forgetting. I'm a computer engineering student. I've had a single 3 hour class on the fundamentals of circuit analysis. That was over a year ago. That's my only experience. My experience at school and at work has been programming for the most part.

 

[IronWing]

Just turn the wall switch off every once and use up the extra 40W that are building up in the socket. Don't use the socket switch as the 40W will just drain back into the house wiring and you'll lose all that electricity. By using the wall switch the watts flow into the bulb and you get to use that electricity instead of just giving it away to the electric company. Be sure to plan ahead so you can make use of the light. If you have had the 60W bulb on for a long time, it would kind of suck to have the 40W burning away when you were trying to sleep.

 

[Eli]

A 60W bulb in a 100W socket is perfectly fine.

A 100W bulb in a 60W socket is NOT perfectly fine.

Originally posted by: Anubis

Originally posted by: Legend
So there's no such thing as a 100 W socket? The power applied is variable?

sre you talking about a normal light socket?

because they cna take ANY light bulb from say 15w to 1000w

Absolutely incorrect.

Don't burn your house down.

 

[classy]

Originally posted by: Anubis
WTF is a 100w socket?

LOL

 

[Saint Nick]

just put the damn bulb in and see what happens!!!!!!!!

 

[flot]

Originally posted by: Legend
Sad thing is I'm a computer engineer student. They don't teach us the simplest things about hardware.

No, the sad thing is that you are a CmpE student and you have never bothered to figure out how a goddamn lightbulb works. Ever think that maybe life has gotten TOO easy?

 

[mercanucaribe]

Originally posted by: Engineer
If you are placing a lower wattage bulb in a socket built for a higher wattage and the voltage is the same for the two bulbs, then yes, it's perfectly fine.

I knew you were an engineer before I looked over the left and saw your username.

Non engineer's answer:
Yes, it will work fine. The 100W is the max rating of that socket.

 

[sharkeeper]

The Underwriters Laboratories has strict guidelines on incandescent fixture thermal contraints. Obviously a 100W bulb will produce more heat than a 60W bulb. This is for fire safety.

It can be said that using a 100W bulb in a fixture rated 60W maximum constitutes a potential fire hazard and such operation is not recommended. Thermoplastics and combustible materials in close proximity of the bulb can deteriorate rapidly or smolder. If the envelope would breach, the probability of said surfaces/materials ignited is much greater.

It is perfectly acceptable to use a 40W bulb in a fixture rated 60W!

Grossly over powering (300W in 60W for example) is just plain foolish and you should never do this. If you really need this much light you should consider alternative ways (HID, for example) or hire a competant lighting consultant to provide a bonafide solution instead of doing something makeshif and risking the integrity of your edifice and increasing the risk of other occupants, etc.

 

[sswingle]

How many CE students does it take to screw in a lightbulb???

 

[sharkeeper]

How many CE students does it take to screw in a lightbulb???

None.

No student that I know of can fit inside a light bulb.

 

[SSP]

How many ATOT'ers does it take to screw in a light bulb?

One to post it, and 40 others to discuss how to screw it in.

 

[hemiram]

How is it possible to get to the age of...12, and not know anything about lightbulbs?

Everyone has them, did the OP have a maid that changed all his?

I would think that anyone who knows anything about electricty at all would know that a light socket is just hooked up to a pair of wires, and that you can always go under the load, and not over it, or you have to go smaller than XX watts due to heat. This seems very simple to me, even as a little kid, I understood this, and while I'm smart, I'm not the smartest person in the world.

I guess maybe I knew because I always have changed my own lightbulbs, going back about 45 years or so.

I don't understand it at all..

 

[cavemanmoron]

Originally posted by: Engineer
If you are placing a lower wattage bulb in a socket built for a higher wattage and the voltage is the same for the two bulbs, then yes, it's perfectly fine.

 

[Mark R]

Presumably the OP is talking about a normal incandescent (filament) bulb, in which case there are no problems using a 60W in a 100W max. fitting.

If he was talking about fluorescent (striplight) lamps, then the fittings do have a specific power rating, and the bulb must match. E.g. an old 5 foot 60W fitting should not be fitted with a (new) 5 foot 36 W low-energy lamp.

 

[mrrman]

yes...its rated for 100W max...you can stick a 20W in there if you want

 

[leftyman]

try a candle

 

[MidasKnight]

up

 

[FoBoT]

yes, that is ok