How to Test a Low-Voltage Lighting Transformer

A low voltage lighting transformer on a white background.
  • 1 hours
  • Intermediate
  • 50
What You'll Need
Volt ohmmeter
Step ladder

To ensure that a low voltage lighting transformer is working correctly to control the lights, there may be occasions when it is necessary to test it. Following a few steps will enable you to complete this process effectively.

Step 1 - Prepare

Begin the process of testing the low voltage lighting transformer by switching off the power supply that serves it. If the transformer is in a high location, position the ladder securely before climbing it to remove the cover. If you have retained the manual that relates to the transformer, it will be useful to check it to determine what to expect.

Step 2 - Apply Wires

You will find that the low voltage lighting transformer comprises two test wires. The red one must be inserted into the recess marked ‘ohms’ on the meter while the black one can be inserted into the common recess.

Step 3 - Check Reading

When testing a low voltage lighting transformer, you are looking for a reading that reflects the output winding. If you get a small Ohms (Ω) resistance reading, you have the correct result. Any large or infinity (∞) resistance reading means that there is an open circuit or defective coil and the transformer must be replaced.