What is a low voltage transformer?

A transformer ?EUR??,,????'??transforms?EUR??,,????'?? electrical voltage from a higher voltage to lower voltage. For example, most houses are on a 120v system. A low-voltage transformer steps down the voltage from 120v to 12v. Most transformers have a E.I lamination core or a toroidal core. We prefer toroidal as this type is more efficient. Note: Electronic transformers are not used in landscape lighting systems.

How are transformers designed?

The basic principal of a transformer is a 10:1 ratio. For example, 120 volts in the primary side will put out 12 volts on the secondary side. Hint: If your house voltage is operating at 110 volts your transformer will only put out 11 volts.

What are the key components of a transformer?

Terminal lug: The access port for low-voltage cables. Common taps represent voltage line that is monitored by a circuit breaker and secondary taps represent voltage load.

Secondary protection: A fuse or breaker that protects over voltage on the 12v side.

How does a transformer work with landscape lighting?

Most landscape lighting systems work on a 12v system. The transformer steps down the house voltage to 12v so that the transformer can supply the proper power to the low-voltage lighting fixtures. Low-voltage lamps will be over loaded if the voltage is higher than 12.0 volts.

How do you size a transformer?

Simply add up the number of watts on the 12v system. For example, if you are using 10 fixtures at 50 watts each, you need to choose a transformer that has at least a 500 watt rating. It is recommended to upsize the transformer so that you have room to add to the lighting system in the future. Generally speaking, transformers operate most efficiently at 80% of capacity.

How do you check for available power on the house panel?

The easiest way to check the availability of electricity is to add the total number of watts on the landscape lighting system. For example, 1,500 watts of landscape lighting will require a minimum available 15 amp breaker (100:1 ratio). If you have other electrical devices on the circuit you may not have enough power to support a landscape lighting system.

Is there a difference between halogen or incandescent lamps?

As far as the transformer is concerned, wattage and voltage are the same regardless of filament type.

What are the key features and options available?

Most transformers have built-in or optional timers, built-in or optional photo cells or manual on/off switches. Some transformers are motion sensor compatible. We like transformers that have photo cell and timer combinations so that you can set activation as follows: photo on (dusk) and time off (as desired).

Do you have to use a transformer from the same manufacturer as the lighting fixtures?

No, as long as the transformer is rated for low-voltage systems. However, please check with the manufacturer?EUR??,,????'???s warranty. Some will not warranty fixtures if you use another brand of transformer.

Are transformers dimmable?

Some are and some are not. You need to check with your supplier. The secondary side (12v) and/ or primary side (120v) can generally be dimmed.

Do transformers get hot to the touch?

E.I lamination type transformers get hotter than toroidal types. A warm transformer is not unusual.

Why choose stainless steel, black or painted transformers?

Simply put, painted steel transformers cost less money. The metal fabrication is subject to environmental issues (water, salt air and other weather related conditions). Stainless steel transformers are less susceptible to weather and environmental conditions but cost slightly more than standard metal units.

What is voltage drop?

Voltage drop is resistance on the cable which diminishes the flow of current causing decreased voltage. Voltage output will decrease as the distance increases from the transformer. Decreased voltage will affect the light output of the lamp and efficiency of the fixture.

Illuminating Info

1/2: Transformers should be used to at least half of their rated capacity as a decrease in capacity increases the output voltage resulting in a shortening of the light bulbs life. Source: SPJ Lighting

900: Maximum recommended wattage of transformers for use on landscape lighting.

150: Minimum recommended wattage of transformers for use on landscape lighting. Source: Fresno Bee