Repair Workshop: frequency inverter (VFD) fault

Start from the code on the keypad or the symptom. At every step we show what to measure, where and how. The DC bus is ≈540 V and stays charged for minutes after switch-off: don't touch anything until you've measured 0 V between P(+) and N(−), and apply first power after a repair through series bulbs or a variac.

Step 1free trial: 3 steps left

What is the drive doing?

🔧 How to measure

Safety first: the DC bus is ≈540 V and stays charged for minutes after the power is cut. Before opening the cover wait for the CHARGE LED to go out (at least 10 minutes) and measure 0 V between P(+) and N(−). Don't touch anything until you have measured it.

🔒 This content is in the repair pack

The repair pack unlocks all interactive content in one go: diagrams and current flows, the Repair Workshop, simulations, concepts, IC guides, the Component Library and comparison guides. One sample in every section is free.

Repair pack: 5,000 ₺, members get 10% off → 4,500 ₺. Or 1-week access for 1,000 ₺.

Want to see how the board works first? Go to the How it works page →