My transformer turns on for a period of time, turns off, then comes back on … why?

admin

Answer
Most low voltage transformers are equipped with thermal protection. If your power unit is undersized (overloaded) it is probably overheating and causing the thermal protection to shut down the unit. Consider using a larger transformer or splitting the load to an additional unit.  Refer to the FAQ on sizing a transformer.

How do I size a transformer for my lighting installation?

admin

Answer
Calculate the transformer required by adding the number of lights X the wattage of the lamps. This is the minimum required output of the transformer.

Example:

  • 10 wall lights @ 11.5 watts = 115.0 watts
  • 5 spot lights @ 35.0 watts = 175.0 watts
  • 6 path lights @ 18.0 watts = 108 watts
  • Total minimum transformer output required 398 watts

Why is my transformer making a humming noise?

admin

Answer
Low voltage transformer cores are built from thin steel laminations stuck together. The cycling on and off over time may have loosened the laminations, creating a slight vibration. This is typical of units that have not been encapsulated with epoxy during the manufacturing process. It does not mean that your power supply will fail.

How do I mount a low voltage transformer?

admin

Answer
Your power supply should be mounted at least 12″ above ground level. Many transformers are not completely sealed and should have that clearance according to UL 1838.

Can I mount my low voltage transformer inside?

admin

Answer
No. Generally speaking, low voltage transformers are listed and labeled for “Outdoor Use Only.” If your installation requires an indoor transformer, consult your local electrical codes … you may be able to purchase a low voltage power supply locally for that use. Remember that if you are using a photocell you may have to make other provisions for controlling the outdoor lighting.

Can I connect an Integral fixture directly to the power supply?

admin

Answer
Yes. A single fixture can be connected without the worry of overpowering the fixture.

How do I minimize voltage drop?

admin

Answer
The closer your incandescent fixtures are placed to the transformer, the higher their voltage (and wattage). The farther away you place the fixture, the lower the voltage it will receive. If a cable run is too long or if too many lights are being powered by a single transformer, noticeable voltage drop may occur.

Voltage drop causes the lights farthest from the transformer to become dimmer than the other lights.

Voltage drop can be minimized in various ways …

  • Heavier gauge cable
  • Use a higher capacity transformer
  • Install multiple transformers
  • Shorten your cable length
  • Reduce individual fixture wattage
  • Reduce the total number of fixtures on a run

Voltage drop actually works to your advantage if differences in lamp brightness levels add a desired look and feel to your installation. Remember … bulbs with lower voltage will last longer, requiring less replacement.

How do I ensure proper lamp life?

admin

Answer
Use of a digital voltmeter is the only way to confirm that your voltage is correct. Keep in mind that a transformer is reducing your primary voltage (house current) as a percentage. The transformer is not a regulator … a regulator would supply a constant 12 volts, no matter the primary voltage. Every installation is unique due to the variations of our power grid.

For LED installations, consider utilizing our LED Electronic Transformer. It automatically adjusts for the load and increases the product and system reliability. Visit our page LED Electronic Transformer for more information.