Finding and diagnosing issues with motor drive systems and their performance requires data from multiple points within the system. Because of their complexity, in the past, this required several tools. Some newer instruments make testing motors and motor drives more efficient because they can capture more types of data, thus requiring fewer tools. In addition, these instruments trend data over time to make changes easier to identify.

These include the Fluke 438-II Power Quality and Motor Analyzer and the Fluke MDA-550 Motor Drive Analyzer. Inefficiencies and excess energy consumption can be identified and confirmed through power quality and motor analysis data. To keep inexpensive downtime at bay, what is the best way to collect these types of data?

Choosing the Fluke 438-II Power Quality Analyzer

In the past, accurate motor analysis data could only be obtained during costly shutdowns, to allow for the installation of mechanical sensors. It also costs thousands of dollars of time and labor to disassemble the motor to install mechanical sensors, ship the motor to a laboratory, pay the lab an hourly rate (up to $10,000 per hour), and finally get the motor back to the right place in a facility.

But today, motor analysis tools such as the Fluke 438-II Power Quality and Motor Analyzer make it possible to measure the electrical and mechanical performance of electric motors, and to evaluate power quality by measuring the input to the motor—without using mechanical sensors.

One key ability of this tool is its ability to measure while motors are in service, making it possible to accurately analyze the real operating conditions of a motor. The ability to quickly and easily identify motor performance issues is essential to any preventive maintenance program.

The 438 can validate power. It can also check motor electrical to mechanical conversion. For example, is the motor getting the power it needs? Is it converting that power to torque to turn the shaft as expected? The 438 can confirm these, as well as pinpoint whether a power quality problem is load side or supply side all based on the motor nameplate information entered into the tool.

The 438 is a must-have instrument to troubleshoot power quality problems and perform routine maintenance for both three-phase and single-phase power distribution systems. Additionally, it identifies both overloaded motors that run to fail, and underloaded motor expense-saving opportunities. The data it collects can be viewed in real time on the instrument. In addition, the screenshots can be sent to your mobile device via the Fluke Connect? mobile app. Downloaded and recorded data and screenshots may be accessed via desktop software.

Choosing the MDA-550 Motor Drive Analyzer

The Fluke MDA-550 Motor Drive Analyzer is designed to make it easy to test and troubleshoot problems on both three-phase and single-phase motor drive systems. It validates drive performance from end to end. Guided test setups and automated drive measurements provide reliable, repeatable test results, and the built-in report generator makes it easy to create as-found and as-left reports.

If your motor drive system is operating at elevated temperatures, losing power, or experiencing random error codes, the MDA-550 can quickly determine and validate whether the drive needs programming, repair, or load adjustment—or whether power supply issues exist.

With the MDA-550, you can verify that input power is within the drive’s operating specifications. RMS measurements and waveform qualitative analysis are two ways to determine this. The MDA-550 can also look at input harmonics or supra harmonics. Comparing current harmonics to voltage harmonics is useful because, if there are no current harmonics but voltage harmonics are excessive, you can move to investigating other loads on the same circuit.

Why should you choose both?

The MDA-550 is a portable test tool that can help you safely locate and troubleshoot typical problems on motor drive systems, such as excessive heat or drive shutdown. One way of tracking performance over time is to use the recording function to plot the V/Hz ratio over the equipment’s operating cycle.

To make sure that each of your motors run for as long as they are designed to, you must be sure they are operating within their specified operating conditions. Using the 438 to verify electrical load, mechanical load, and NEMA derating will help you reduce operating costs, increase motor lifespan, and avoid costly shutdowns. With the 438, you can eliminate power supply as a cause of drive problems, as well as identify both overloaded or underloaded motors. The MDA-550 validates drive performance from end to end, troubleshoots root causes, and isolates component failures.

Combined, the 438 and the MDA-550 enable you to comprehensively analyze key performance metrics so you can make informed decisions and maximize your uptime and efficiency. Motor drive systems can be complex and being able to see exactly how they are performing under operating conditions can help you get the most out of each component.

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