Before you get ready to plug in your Christmas lights this
year, learn how to calculate the power needed to run your amazing display. So what do you need to know to get started?
First things first, you need to know the wattage of your Christmas lights, the
Amps your lights use, the circuit
breaker size on the outlets you will be plugging them into and you need to know
the voltage of the outlets.
Check your Voltage on your outlets and your Christmas Lights
In the US a standard household outlet runs on 120 volt
power. The standard circuit breaker size is generally 15AMP and often controls
multiple outlets in a house or outside. Standard Christmas Lights in the US are
generally 120 volt so just make sure what you purchase matches the voltage you
have available. Some commercial properties or boats use 12 volt power and so
you will need to match the voltage to your Christmas lights to have them work
Check your circuit breakers Amps
Standard US household circuits generally run on 10, 15, 20
or 30 Amps. The average is a 15 Amp
circuit breaker. This tells you how many
Christmas lights you can have going to that circuit breaker. Your 15
Amp circuit can handle up to 1440 watts of power. Make sure you know what other items may be
plugged into the circuit before you overload it. We had a house once that had
the outdoor outlets wired on the same circuit as our bathroom power outlets so
anytime we used indoor small appliances like a blow dryer when the Christmas
lights were on we tripped the breaker! So annoying, it took some time to figure
out where the correct GFI to reset the circuit was.
Check the wattage of your Christmas Lights
Standard mini Christmas lights use 40.8 watts of power per
strand of 100 bulbs.
Standard C7 Christmas lights use 5 watts per bulb or 500
watts for 100 bulbs.
Standard C9 Christmas lights use 7 watts per bulb or 500
watts for 100 bulbs.
High quality LED mini Christmas lights use 4.8 watts for a
strand of 50 bulbs.
3 diode C7 LED Christmas lights use a little less than .8
watt per bulb or 80 watts for 100 bulbs.
5 diode C9 LED Christmas lights use 1 watt of power per bulb
or 100 watts for 100 bulbs.
Now calculate your total power needed
If you don’t want to end up like the Griswold’s you need to
know exactly how many strands you are using and plugging together. UL rating suggests
you should use no more than 210 watts end to end on traditional mini light
wiring (22AWG), this is generally 5 strands of 100 mini lights. If it is 20AWG
wiring this rating goes up to 420 watts. If you are using C7 we recommend using
no more than 100FT end to end, but you can put up to 288 standard 5 watt bulbs
on a 15 amp circuit (again, follow the rule of using no more than 1440 watts of
power on a 15 amp circuit).
1440 watts will allow you to use approx. 100FT of C7 light
line on your roofline and an additional 22 strands of mini lights on trees,
shrubs or bushes to decorate your house.
If you are ever in doubt, please contact us to get power
recommendations on your project. As
commercial decorators we understand power needs and can give you suggestions
and ideas to decrease the power needed without sacrificing the look of a
beautifully decorated property for the Christmas season.