Sealed Beam Worklight Amperage

Bob_Young · Dec 27, 2004

Bought a 4 1/2" sealed beam worklight for the L4300 today. It's a 12 volt unit with a GE L4611 sealed beam lamp.

Nothing on or in the box indicates the lamp amperage or wattage requirement. The ohmmeter shows cold filament resistance at 0.5 ohms. This can't be correct as an operating resistance as the light would draw 24 amps /forums/images/graemlins/shocked.gif!

Anyone know what the operating current requirement of a 12 volt sealed beam lamp is? I suspect it's around 5 amps but don't know for sure.

Thanks.
Bob

KiotiJohn · Dec 28, 2004

Surely there is some making on the glass of the lamp that indicates the wattage of the lamp. I can find no reference to this model of GE Bulb and they can be all manner of wattage.
Look for embossed lettering that may tell the tale.
Is this a round sealed beam? John

Bob_Young · Dec 28, 2004

Yes, John, it's round. It's a simple thing with the bulb sort of jammed into a rubber cup-like affair that serves as the housing. A single wire comes out of the back of the cup. A bracket riveted to the bottom of the cup serves as the electrical return.

I tried popping the bulb out of the cup to see what's on the back, but it wasn't going too well so I gave it up in favor of checking with the braintrust. I'll try it again. The L4611 bulb number came from the box; 'GE' is embossed in the center of the lens. ARRRGGGGHHH! Checked again, it's L4411 /forums/images/graemlins/blush.gif, my mistake. Sorry, 'nother Senior Moment /forums/images/graemlins/crazy.gif.

Thanks for taking time to check.
Bob

wvhillbilly · Dec 28, 2004

I believe those sealed beam bulbs are generally 55 watts which gives a current draw of 4.58 amps. Multiply this by the number of lights you hook up to get total current draw. Ex.. 3 work lights.. 4.58 * 3 = 13.74 amps. I guess they could come in 100 watt flavors in which the current draw for one light would be 8.3 amps. The equation for figuring out the current is:
Current = wattage / voltage.

in this case 55 watts/12 volts=4.58 amps
or
100 watts/12 volts = 8.3 amps

Dave

billfires · Dec 28, 2004

Bob, from GE web site the 4411 is a 35 watt bulb which would make it under 3 amps. Bill C

Bob_Young · Dec 28, 2004

Thanks bill and billy. This thing isn't anything special so I'd be surprised if it's 100 watts. I've allowed for up to 5 amps, so I figure I'm good to go.

35 watts? Well that's even better /forums/images/graemlins/smirk.gif.
Bob

BB_TX · Dec 28, 2004

<font color="blue"> cold filament resistance at 0.5 ohms </font>
The resistance of the filament increases as it heats up. There will be a high inrush of current that will quickly fall off as the resistance increases.

Zork · Dec 28, 2004

Nice use of ohms law. /forums/images/graemlins/wink.gif

an easy way to remember is the "magic triangle"
P
-------
E I

Where: p= watts, E = volts, I = amperage. Put your thumb over what you want to find. Example: to find amps, cover I and divide watts by volts. To get watts, multiply E by I, that simple!

Also works for
E
--------
I R

Where: E= volts, I= amps and R = resistance. To find resistance, cover R and divide voltage by amperage. Even if my math doesnt work, this formula does. Hope this helps all. /forums/images/graemlins/grin.gif

You guys are GREAT. Since I've loosed my belt one notch I decided I cant eat any more crow, lol. Just thought that I'd save myself some heckling in the future. Franz

Inspector507 · Dec 28, 2004

<font color="blue"> divide 12 by .5 and that should be 6 amps </font>

Now, do it on your calculator.....
12 divided by .5 equals 24 on mine /forums/images/graemlins/grin.gif