Frequently Asked Questions (FAQ) about Microwaves and Electricity Frequency

My microwave turns on and the light works, but it's not actually heating food — why?

QI brought my US microwave to Germany with a step-down transformer. The display lights up, the turntable spins, and it sounds like it's running, but food comes out barely warm even after several minutes. What's going on?

AThis is the single most common frequency-related failure we hear about, and microwaves are the least forgiving appliance for it. Inside the microwave, a transformer steps voltage up to power the magnetron, the component that actually generates the microwaves that cook your food. That internal transformer is designed around 60Hz; on 50Hz power its core has to carry roughly 20% more magnetic flux than it was built for, which can push it toward saturation. The practical result is exactly what you're seeing: the control panel and turntable (low-power circuits) work fine, but the magnetron never reaches the power level needed to actually cook — and in worse cases the internal transformer overheats and eventually fails. A voltage transformer can't fix this because it never touches frequency at all. You need a real voltage and frequency converter that outputs genuine 120V/60Hz.

Will running my microwave on the wrong frequency damage it permanently?

QWe've been running our US microwave on 50Hz through a regular transformer for a few weeks and noticed it's started making a louder humming noise than before. Should we stop using it?

AYes, we'd stop using it on that setup. A louder hum is often the internal transformer working harder than it was designed to — a sign it's running warmer, which shortens its life and can eventually take out the transformer or the magnetron entirely. This is one of the appliances where the wrong-frequency damage tends to be cumulative and often ends in outright failure, rather than just reduced performance. Switch to a proper frequency converter as soon as you can; if the humming continues even after switching to correct 60Hz power, have the unit checked, since sustained 50Hz operation may have already stressed the internal transformer.

How much power do I need for a typical 1000–1500W microwave?

QMy microwave's label says 1500W. What size converter should I be looking at to run it safely?

ASize the converter to your microwave's rated wattage with some headroom for the brief startup draw, not just the number on the door. For a 1500W unit, our X-15 (1800W/15A) gives you comfortable margin; if you're also planning to run other kitchen appliances on the same converter, size up further to cover the combined load. Undersizing is the most common mistake we see — a converter that's just barely rated for the microwave alone leaves no room for other loads or for the slight surge every appliance draws the instant it switches on.