Fluke MDA-550 Series III

The Fluke MDA-550 Series III is a 4-channel motor drive analyzer that combines motor drive analysis, waveform measurement, and data logging into a single portable instrument. Built for field and lab troubleshooting of inverter-type motor drive systems, it delivers guided test sequences, preset measurement profiles, and graphical connection diagrams to streamline setup and ensure repeatable results. The device captures electrical behavior from power input through motor terminals, supporting single-phase and three-phase configurations.

An integrated report generator produces documented "as-found" and "as-left" reports for rapid job closure and compliance tracking.

Technical Specifications

• 4-channel analyzer with 500 MHz bandwidth


• DC voltage accuracy: ±(1.5% + 6 counts)


• True-RMS voltage accuracy: ±(1.5% + 10 counts) DC to 60 Hz; ±(2.5% + 15 counts) 60 Hz to 20 kHz; ±(5% + 20 counts) 20 kHz to 1 MHz; ±(10% + 20 counts) 1 MHz to 25 MHz


• Maximum voltage measurement: 1000 V with 10:1 or 100:1 probe


• Resolution: 1 mV / 10 mV with 10:1 or 100:1 probe


• PWM, peak, and modulation voltage measurement supported


• DC bus voltage, voltage unbalance, and current unbalance analysis included Safety & Environmental


• 600 V CAT IV / 1000 V CAT III rated


• 1000 V CAT III / 600 V CAT IV at service entrance and downstream


• Maximum floating voltage: 1000 V CAT III / 600 V CAT IV


• VPS421 probe rated to 2000 V between tip and reference


• Operating temperature: 0–40 °C


• Pollution degree 2 per IEC 61010-1

Key Features

• Input and output current measurement with unbalance detection


• Voltage unbalance assessment at drive input


• DC bus ripple and voltage level trending


• Guided troubleshooting workflows reduce setup time


• Portable design for HVAC/R, motor repair, and manufacturing environments

Typical Applications

• Inverter drive diagnostics and commissioning


• Motor circuit troubleshooting


• Power quality assessment at motor terminals


• Field service and preventive maintenance


• Motor repair and rewind verification

Compatibility & Integration Accepts VPS410-II (1000 V working voltage) and VPS421 (2000 V working voltage) probes. BNC input rated 300 V CAT IV.