AC Drive Testing Procedure

How to test and troubleshoot power component of 𝗔𝗖 𝗗𝗿𝗶𝘃𝗲 or 𝗩𝗙𝗗? What need to check? How to identify defective component?

This 𝗔𝗖 𝗗𝗿𝗶𝘃𝗲 𝗧𝗲𝘀𝘁𝗶𝗻𝗴 𝗣𝗿𝗼𝗰𝗲𝗱𝘂𝗿𝗲, could help drive engineer, technician and maintenance personnel to test / check AC Drive power component, and troubleshoot:

▪️ Blown input fuse / MCCB trip
▪️ No output voltage
▪️ Converter / Rectifier Section
▪️ DC Bus Capacitor
▪️ Inverter / IGBT section
▪️ Shorted component

As shown on page 1, AC Drive or Variable Frequency Drive ( VFD) or sometimes called inverter, consist of 3 main power section:

1️⃣ Converter / Rectifier
It is used to convert or rectify 50/60Hz AC voltage to unfiltered DC Voltage.

2️⃣ DC Link Filter or DC Bus
Consist of DC Coke and capacitor and used to smooth out the ripple of DC voltage and store DC voltage

3️⃣ Inverter or Power module
It is used to convert back from DC voltage to AC voltage to drive motor.
Inverter is controlling frequency and the voltage of drive output.