Outdoor C7 and C9 Lamps
Christmas Light Information
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Low Energy C7 and C9 Lamp Information Hanging Outdoor Christmas Lights Calculating Maximum Runs and Wattage C7 and C9 Picture Gallery
This section contains information about traditional outdoor Christmas lights: C7 Lamps and C9 Lamps plus answers to frequently asked questions about outdoor C7 and C9 Light Strings. Click on the links above if you wish to go directly to information about our new Low Energy Lamps,  Hanging C7-C9 Christmas Lights, Calculating Maximum Runs and Wattage or our C7-C9 Picture Gallery.
What are C7 and C9 Lights?
C7 and C9 Outdoor Christmas Lights are larger than small mini-style Christmas lights and are often considered traditional outdoor Christmas lights. Traditional C9 and C7 Lights are heavier-duty than mini-lights and are more reliable. Christmas C7 and C9 bulbs screw into a candelabra base socket and can be replaced with standard Christmas bulbs called lamps. These "traditional" light strings are designed in such a way that if a single bulb fails, it only affects that bulb. Individuals often use C7 or C9 Light Strings to decorate large outdoor Christmas trees, outline building perimeters or simply to decorate the outside of their homes. Both C7 and C9 lamps or bulbs come in a variety of colors while the base socket and wire can be purchased in green or white. 		C7/C9 Christmas Outdoor Light Bulb

Christmas Light Outdoor C9 Bulb

 Christmas large light outdoor C7 Lamp What are the differences between C7 and C9 Outdoor Christmas Lights?
The main differences between C7 and C9 Christmas lights are the bulb or lamp size, base size, and the wattage. C7 bulbs are smaller than C9 bulbs with C7 bulbs just over 2 inches, while C9 bulbs are just over 3 inches long.  Our C7 lamps come in 2.5 Watts and 7 Watts while our C9 lamps are 3.5 Watts and 7 Watts.  C-9 Lights are useful for decorating buildings, particularly those that are 2 stories or more, as these bulbs appear to shine brighter and seem more visible from a distance.
   
What are the differences between different base sizes on light bulbs?
The commonly used light bulb bases in holiday lighting are candelabra base and intermediate base. A C7 bulb has the smallest base called a candelabra base and a C9 bulb has a larger base called an intermediate base. For each type of base, there is a corresponding socket size. For example, a light bulb with a candelabra base will fit only a candelabra socket. Therefore, when purchasing light strings, be sure to purchase bulbs with compatible bases. If you purchase light strings with intermediate sockets, be sure that the light bulbs you purchase also have a intermediate base. 

What lengths are your C7 and C9 Outdoor Christmas Light Strings?
Our C7 and C9 Stringers are made of 18 gauge wire and come in strands of 25 Lamp Strings, 100 Lamp Strings, or 1000 Lamp Reels. Lamps are spaced 12 inches apart on our 25 and 100 Lamp Strings.  On our 1000 Lamp Reel, the sockets are spaced 12, 15 or 18 inches apart. When purchasing lights, choose the spacing according to the look you want to achieve. Generally, the farther away the lights, the farther apart people want the lamp spacing.  This is because the farther away the lights, the closer the spacing appears.

How many lights will I need to decorate a Christmas tree?
First, large Christmas lights should not be used to decorate indoor Christmas trees since they generate too much heat and could create a fire hazard.  When decorating outdoor Christmas trees, C7 Lamps are often used on Christmas trees that are 3-6 feet tall while C-9 Lamps are usually used on Christmas trees that are 6 feet or taller.
          For a minimally lit tree, use the following number of lights:   Multiply -  Height (ft) x Width (ft.) x 1.5
          For a well-lit tree, use the following number of lights:   Multiply  - Height (ft.) x Width (ft.) x 3
          For a rough estimate use the following chart:

Tree Height

Number of Lights
3 25
4 50
5 75
6 100
Add 25 lights for each additional foot.

How do I calculate the total number of bulbs that can be run on a single circuit?
The following table gives a good idea as too the number of bulbs that can be run on a single circuit. For more details and specific formulas, go to Calculating Watts and Amps.
C7 or C9 Lamp Wattage Lamps per Outlet Lamps per 15 Amp Circuit Lamps per 20 Amp Circuit
2.7 Watts 300 Lamps  576 Lamps 768 Lamps
3.7 Watts 250 Lamps 389 Lamps 519 Lamps
5 Watts 175 Lamps 288 Lamps 384 Lamps
7 Watts 125 Lamps 205 Lamps 274 Lamps

How many sets of C7 or C9 Outdoor Christmas Light Strings can I plug in together?
When using C7 or C9 25-Lamp Strings, do not connect more than three strings in a series. You can connect two of our C7 or C9 100-Lamp Strings together IF you use a 3 Outlet Power Adaptor plug in between the two light strings.  You should never connect 100-Lamp Strings together without the 3 Outlet Power Adaptor. The exception to this rule is our Low Energy/High Efficiency Lamps in which case you can run twice as many strings as stated above.

Can I plug a C7 Lamp String into a C9 Lamp String? What if they are the same wattage?
No. You cannot mix the two types of strings, even if they are the same wattage.

Can I connect C7 or C9 bulbs that have different watts?
No. You cannot connect stringers that contain differing watts of C7 or C9 bulbs.

Why are some of my outdoor traditional Christmas lights brighter than others?
Several factors can effect the brightness or look of our lamp. Different watts produce different brightness. Generally the higher the watts, the brighter the bulb. One exception to that rule is our High-Efficiency/Low Energy Bulbs. C7 and C9 Christmas Bulbs have either a double dipped or triple dipped coating of color.  The less a lamp is dipped, the brighter the bulb.  Age can effect the color of a lamp.  Lamps that have weathered a season outdoors usually have lost some of their protective coating and as a result, they appear brighter than freshly dipped lamps.  To achieve a more consistent look, you may want to use lamps that are the same age, same wattage, and have been dipped the same number of times.