Globe Light Size Comparison + Calculating Amperage

Globe lights come in a variety of sizes, and I'll be the first to admit that the designations G30, G40, and G50 do not give a clue as to the size of the bulbs! Just remember the larger the number, the bigger the bulb. G50 are the globe bulb that most people think of when they think of globe style light bulbs, these are a large 2" diameter bulb. These styles of bulbs are available on both C7 (candelabra) base and C9 (intermediate) Base, we have some options for Medium base which is the size of a household light bulb but you'll have to call or email us for info on those bulbs.

More than just the size varies with Globe light bulbs, wattage of bulbs varies as well. G30 and G40 with a C7 (candelabra) base are 5 watts, where as C7 base G50 bulbs are 7 watts. You have to take this into consideration when decorating with globe lights because you DO NOT want to overload your wire. Speaking of which, here's the math on calculating amps for wire:

(Bulb Wattage) x (Number of Bulbs) = Total Wattage
(Total Wattage) ÷ 110 (Volts) = Amps

Example; Standard SPT-1 Wire handles 7 amps, so you do not want to exceed this, lets say you have 100 G4 Globe bulbs that are 5 watts a piece, your calculations should look like this

5 Bulb Wattage x 100 Bulbs = 500 Watts

500 Watts ÷ 110 Volts = 4.55 Amps

So as you can see, 4.55 amps is below so you can safely use 100 Globe bulbs on SPT-1 Wire. Most stringers we carry are SPT-1 unless noted and our spools of light light is available in both SPT-1 and SPT-2 options.

I hope this cleared up the confusion on bulb size of Globe lamps and let you have a little insight on how to decorate safely by calculating how many amps your number of bulbs are going to use.

Please visit our Globe Lights Page today!

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Zach
All American Christmas Co.
www.aachristmas.com
www.allamericanchristmas.com