Transformer Knowledge
How transformers work and what to do when they fail. Wiring, testing, safety, noise, efficiency and troubleshooting.
Frequently asked questions about transformer knowledge
How do I test if a transformer is working?
With the power off, check continuity across the windings with a multimeter. Then power up and measure output voltage - it should match the nameplate within a few percent. No output usually means a failed winding.
Why is my transformer humming?
A low hum is normal - it comes from the laminated core vibrating at line frequency. A loud or growing hum usually points to loose laminations, a DC component on the line, or the transformer running overloaded.
What does the VA rating on a transformer mean?
VA is volt-amps, the apparent power a transformer can deliver. For resistive loads like heaters, VA equals watts. For motors and electronics, watts sit below VA, so always size by VA to stay on the safe side.
Is it safe to leave a transformer plugged in permanently?
Yes - our units are built for continuous duty and carry thermal protection. Keep the case ventilated and away from moisture. If it gets too hot to hold, unplug and check the load, because that means overload.
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