Motor Tripped?
Analyzing the motor current for transient In-Rush peak and Start-Up time is a standard approach to troubleshooting a tripped motor. An instantaneous trip might indicate a stator or trip set…
Tip of the Week
WRM – Pole Pass Frequency With No Rotor Bars?
A Wound Rotor Motor (WRM) is an induction motor typically found in cranes, hoists, compressors, conveyors, mixers, fans, blowers, mills, and pumps. However, unlike the very common squirrel cage induction…
ANSI/EASA Standard AR100
A commonly used and well-respected standard in the electric motor testing industry is the Recommended Practice for the Repair of Rotating Electrical Apparatus (AR100). Furthermore, this standard is provided by…
New Year Motor Reliability Tip – 2023
A new year reminds us it is time for an annual review of our test measurement alarm setpoints. We should annually review the setpoints to make sure they are not…
Humidity and Insulation Resistance
Humidity, like temperature can affect insulation resistance-to-ground measurements. Depending on the humidity level and ambient temperature, moisture may settle onto the cables, windings, motor frame, etc. This will affect the…
From Quality Assurance to Troubleshooting… Don’t skip the Baseline!
Equipment and Human Resource limitations such as technicians and analysts, play a role in our everyday lives as maintenance and reliability professionals. We are often in a position where we…
Split Peak at the 5th Harmonic
When analyzing current signature analysis, like the PdMA EMAX Rotor Evaluation Test, the primary focus starts at the Pole-Pass-Frequency (Fp) sidebands around line frequency. Elevated Fp sidebands can be indicative…
Motor Repair and Inductance
Deenergized stator inductance is a valuable tool in identifying the internal magnetic condition of your electric motor. It is important to know that inductance measurements can be influenced by the…
Reliability Justification
We have all seen the Bathtub Curve and its application to equipment reliability. This curve shows a high failure rate early in life (Infant Mortality), low failure rate throughout the…
Tips for Installing Motor Test Access Panels
To minimize the risk of being in the vicinity of high voltage when testing your electric motors, your electric reliability team or plant safety management may have opted to install…
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