Power Consumption C7 / C9 / Mini-Lights / LEDs

Planning a safe and successful holiday lighting project requires some preparation. One of the more important aspects in this preparation is determining the total amount of power you will need for the upcoming season. We hope the following information will prove beneficial in determining your power requirements.

Knowing the Wattage

A simple and easy to use formula in determining how much current (Amps) is required to safely operate your C7 and C9 light strings is to first determine the power (Watts) required for your bulbs. Most C7 and C9 bulbs sold by Christmas Lights Etc are 5W, 7W and 10W. The higher the wattage of the bulb the greater the light output. Simply multiply the wattage of the bulb by the number of bulbs in the light string. The result is the total wattage/power requirements of your bulbs. Dividing this total by 120 Volts results in the amount of current draw (Amps) required to illuminate your light string.

Example: (100 Bulbs X 5W Bulbs = 500 Watts / 120 Volts = 4.17 Amps)

Once the amps are calculated, determine the compatible light string for the light bulbs you selected. Christmas Lights Etc. offers light strings with the following current ratings: 5 Amp, 7 Amp, and 10 Amp. The designation SPT1/SPT2 indicates the thickness of the insulation on the wire. Both SPT1 and SPT2 wiring are 18 gauge with SPT2 wire having a thicker outer insulation jacket. The thicker insulation jacket allows a greater dissipation of heat and a higher amperage rating for the wire. This is of importance when selecting a higher wattage bulb and calculating the maximum number of bulbs that can be added to a light string.

Wires or light strings and strands are available in precut lengths and in commercial 150' spools, which can be custom cut to your desired length. You may also purchase light strands with differing socket spacing. Many strands come with fuses built into the power plug. Some light strings have stackable power plugs that allow you to stack additional power plugs into the initial power plug. Also available are end-to-end plugs, which allow connection of one or more light strings together in sequence.

Connecting the Light Strings Together

Some lights strings can be connected together while others may not. Certain light strings purposely do not have end plugs and are designed to be stand-alone plugs. Never attempt to splice this type of string together as this would exceed the maximum rated amperage of the wire. Exceeding the capabilities of the wire could cause overheating and possibly melting of the wire and create a potential fire hazard. The above formula will insure you do not exceed the amperage rating of your light string. A safe guideline to observe is to never exceed 80% of the amperage rating of the fuse.

Commercial Light Spools

Example:Our 5 Amp light strings come with a 5 Amp fuse. Only connect the number of strands or light bulbs that would not exceed a maximum draw of 4 amps through the fuse/light string.

Example:You decide to create a custom length light string using a 150' commercial reel with the bulb sockets spaced 12" apart and the wire rated for 10 Amps using 7-Watt bulbs. How many bulbs can you use and what should be the maximum length of the light string? If you were to use 137 bulbs X 7 Watts/Bulb = 959 Watts required for the light string. Dividing 959 Watts / 120 Volts = 7.99 Amps utilizes 80% of the rated current rating (Amps) of the light string. Selecting a light string with bulb spacing 12 inches apart, you can safely run 137' of 7-Watt bulbs on a 10 Amp light string. NOTE: If you ever need help with calculations, we are just a phone call away!

137 bulbs x 7watts = 959 watts

959 watts / 120 volts = 7.99 amps

Mini Light Strings

Mini Lights power requirements are relatively easy to compute. Most 100 Mini-lite sets draw 50 watts per set. Referring back to our earlier example to convert watts to amps we find the following calculation: 50 Watts / 120 Volts = .4 Amps (rounded). All 35 and 50 Mini-lite sets draw .2 Amps per Set. The reason the 35 light sets draw the same amperage is they use 3.5V lamps as opposed to 2.5V lamps on the 50 and 100 Mini-lite sets. A maximum of 3 sets can be connected together based on the limitations of the 22-gauge wire strands associated with non-commercial mini-lite strings. Commercial mini-lite strings have a heavier duty 20-gauge wire allowing up to 6 sets to be connected.

LED Christmas Lights

Our LED Christmas Lights come in two grades, Premium and Commercial. C7 and C9 LEDs are 25 light sets with the following specs, 0.02 Amps, 2.4 Watts per set. This set has a standard A/C male plug on one end that plugs into your power source and a female plug on the other end for connecting additional sets.

Our commercial LED light strings have non-conventional connectors allowing up to 210 sets to be connected together. Power is provided to each run of light strings through a commercial LED adapter that plugs into your power source. The commercial LED adapter houses a full bridge rectifier. The rectifier significantly reduces the flickering light effect observed with some LED lights and light strings.

Will you have a Green Christmas this year?

Run more with less! Retrofit LED Light Bulbs screw into your existing C7 or C9 light strings and are packed with energy savings! Buy early for the best selection.