Troubleshooting a VFD Fault Instantaneous Trip Including Bypass

A new inline ventilation motor operating on a VFD with bypass tripped on startup with the VFD and instantaneously tripped when tested across the line. Smoke was noted in the drive cabinet and MotorDoc was contacted to evaluate the electric motor and work with the VFD installer following recommendations by repair shops to remove the…

Before and After Motion Amplification Testing of Fan Application

Initial testing of an ID fan performed in 2018 with corrections made and retesting performed with EMPATH analysis, GTI Predictive vibration analysis and RDI motion amplification. While values were not extreme in the pre-test, the resulting vibration destroyed fan bearings and other poor conditions which prevented the operation of the fan system. Testing was performed…

Time to Failure Estimation with ESA Series Part 1 Electric Motor Theory

As we start into ESA theories and application, we will have to spend a little time on electric motor theory.  As we will start out with a basic system, AC motors are the simplest in terms of operation and components, we will start out with AC induction motors.  Using this base knowledge, we can later…

Insulation Death Due to Old Age

It does happen, although rarely, in typical industrial environments that an electric machine will die of old age.  The reason is that machines are often exposed to contamination issues, other environmental issues, power issues or a combination of events that degrade the insulation slowly or rapidly. There is also a rule of reliability that should…

EMPATH Electrical Signature Analysis for the Wind Industry for Generator and Powertrain

Free Seminar April 20, 2020 from noon to 1pm CST We will discuss the art of EMPATH data collection and analysis of wind turbine generators, gearbox, main bearings and blades from the voltage and current. We will discuss how the data is collected and the approach to analysis. This will be exclusive for wind companies…

How to Analyze a Belted Fan with EMPATH and Electrical Signature Analysis

Free Live Seminar for April 17, 2020 from noon to 1pm CST In this presentation we will work step-by-step how to analyze an electric motor, sheaves, belts and fan including related bearings using real field data. The demonstration will be with the EMPATH system but applies to other current and electrical signature analysis. GoToWebinar to…

Wind Powertrain with EMPATH

Kevin Alewine of Shermco and I presented at the American Wind Energy Association Operations and Maintenance Conference (AWEA O&M). The EMPATH data on just under 400 generators and powertrain resulted in 772 findings on a specific manufacturer’s generators. The general industry findings for these generators are: The findings from the EMPATH evaluations: The generator findings…

Evaluation of Stator and Rotor Interturn Stress with Electrical Signature Analysis in Variable Frequency Drive and Wind Generator Applications

Abstract— Electrical Signature Analysis is the application and analysis of Voltage and Current data collected on electrical machinery systems.  The measurements are converted to amplitude modulated Fast Fourier Transforms that can be evaluated for power, machine and powertrain conditions.  Electrical and mechanical conditions are determined through their effects on the airgap magnetic field.  One of…

Evaluating Direct-Current Motors Using Motor Circuit Analysis Basics

Howard W Penrose, Ph.D., CMRP MotorDoc LLC, www.motordoc.com The term MCA (Motor Circuit Analysis) is derived from a test method that provides information on the basic components of an alternate-current (AC) or direct-current (DC) electric motor. These basic components include: resistance, measured in Ohms; impedance, measured in Ohms; inductance, measured in Henries; the induction winding…