TRANSFORMER BASICS

 
Low voltage lighting uses a transformer that is plugged into a standard wall outlet to convert 110 volts down to 12 volts. Installation is easy and safe and usually does not require an electrician.

HOW TO CALCULATE TRANSFORMER SIZE

To determine the size of the transformer add the total number of light fixtures and multiply by the number of watts per fixture. (You may want to leave some room to add more lights in the future.)
Number of Lights = 8 rated at 18 watts each
 
Add 10% for cables and connections.
8 lights x 18 watts = 144 x 1.1 = 158.4
 
Round up to the next transformer size. 
Choose a 200 Watt Transformer
 
To prevent stress and early burn out on the bulbs always use at least 50% of the total transformer capacity.

POWER TYPE: A/C or D/C TRANSFORMER

Check the item description to determine power type.
 
A/C Transformers are most common and are used with incandescent and Halogen bulbs. Some LEDs are rated for both A/C and D/C power. Many A/C transformers have features such as photo-eyes and timers.
 
D/C Transformers are used with most LED fixtures. Although some LEDs are rated for both A/C or D/C power. Most LED lights tend to draw a small amount of power (1 to 3 watts per fixture), therefore D/C transformers tend to be smaller in physical size and wattage capacity than A/C Transformers.

HIGH QUALITY TRANSFORMERS

The transformer is the heart of your lighting system so choose quality over price. Lower grade have a shorter life expectancy and may shorten the life of your bulbs. Other features you may look for when choosing a transformer

• High and low switches, similar to a dimmer
• Thermal protection to prevent overloading
• Built-in photo eye for auto on at dusk.
• Built-in timer for convenience.