Fluke MDA-550 [FLUKE-MDA-550] 500MHz, 4 Channel Motor Drive Analyzer with Motor Shaft and Harmonics

The Fluke MDA550 Motor Drive Analyzer, 4 Channel, 500 MHz with Motor Shaft and Harmonics simplifies complex motor-drive troubleshooting with guided test setups and automated drive measurements that provide reliable, repeatable test results on three-phase and single-phase inverter type motor-drive systems. The new Fluke MDA-550 Motor-Drive Analyzers save time and eliminate the hassle of setting up complex measurements, while simplifying the troubleshooting process. Simply select a test and the step-by-step guided measurements show you where to make voltage and current connections, while the preset measurement profiles ensures data capture for each critical motor-drive section-from the input to the output, the DC bus, and the motor itself. The built-in report generator can quickly and easily generate as-found, and as-left reports.

The MDA-550 measures input voltage and current to quickly see whether values are within acceptable limits by comparing the drive's nominal rated voltage to the actual supplied voltage. The system can then check the input current to determine if the current is within the maximum rating and the conductors are suitably sized. This model allows the user to check the voltage unbalance at the input terminals to ensure that the phase unbalance is not too high (> 6-8 %), and that the phase rotation is correct, as well as to check the current unbalance, as excessive unbalance may indicate a drive rectifier problem.

Excessive harmonics are not just a threat to rotating machines but also to other equipment connected to the electrical power system.The MDA-550 visually displays the waveform shape for visual inspection to check whether the harmonic distortion is within an acceptable level and also offers a harmonics spectrum screen which shows both the total harmonic distortion and individual harmonics. This model also has three harmonic ranges, 1st to 51st Harmonics, 1 to 9 kHz and 9 kHz to 150 kHz giving the ability to detect any harmonic pollution problems.

Voltage pulses from a variable speed drive can couple from a motor's stator to its rotor, causing a voltage to appear on the rotor shaft. When this rotor shaft voltage exceeds the insulating capacity of the bearing grease, flashover currents (sparking) can occur, causing pitting and fluting of the motor bearing race, damage that can cause a motor to fail prematurely. The MDA-550 are supplied with carbon fiber brush probe tips that can easily detect the presence of destructive flashover currents, while the impulse amplitude and count of events will enable preventive action before failure occurs.

In a motor-drive the conversion of AC to DC inside the drive is critical, having the correct voltage and adequate smoothing with low ripple is required for the best drive performance. High ripple voltage may be an indicator of failed capacitors or incorrect sizing of the connected motor. The record function of the MDA-550 can be used to check DC bus performance dynamically in the operating mode while a load is applied. Additionally, this model allows the user to check the output of the drive, focusing both on voltage to frequency ratio (V/F), and voltage modulation. When high V/F ratio measurements are experienced, the motor may overheat. With low V/F ratios, the connected motor may not be able to provide the required torque at the load to sufficiently run the intended process.

Measurements of the Pulse Width Modulated signal are used to check for high voltage peaks which can damage motor winding insulation. The rise time or steepness of impulses is indicated by the dV/dt reading (rate of voltage change over time), this should be compared to the motor's specified insulation. The measurements can also be used to measure switching frequency to identify whether there is a potential issue with electronic switching, or with grounding, where the signal floats up and down.