Blog
Notes on reading fault records, written for the engineer who has the file open and needs an answer.
- Fault analysis
ABB Relion COMTRADE Export: Disturbance Records From a REX610 or 615 Series
Sourced from the ABB REX610 manual: why the binary channels are coarser than the file says, why the analog values are primary peak instead of secondary RMS, and the filename that encodes the relay IP address.
- Fault analysis
MiCOM COMTRADE Export: Getting a Disturbance Record Off a P14x
Sourced from the Schneider MiCOM P14x manual: why the file off the rear port is not COMTRADE yet, why a relay holding 50 records will only surrender 8, and the CT ratio setting that silently writes a channel of zeros.
- Fault analysis
GE UR COMTRADE Export: Oscillography Files From a D60 or L90
Sourced from the GE D60 manual: the four artifacts a UR relay writes about a fault, which one is the waveform, why the stored sample rate is a quarter of what the relay measured, and the setting that erases every record.
- Tools
WaveWin Alternative: Web Based COMTRADE Fault Record Analysis
Softstuf WaveWin and Detego compared, sourced from the WaveWin manual: the two export settings that silently change what a record contains, what merging drops, and who should stay on WaveWin.
- Tools
SIGRA Alternative: Web Based Fault Record Analysis
Siemens SIGRA and Detego compared view by view, sourced from the SIGRA V4.61 manual: where each one fits, what SIGRA does that Detego does not, and how to move a record across.
- Fault analysis
SEL Event Report Format: EVE, CEV, and COMTRADE Explained
What an SEL relay writes when it records a fault: the ASCII event report, the compressed CEV form, and the binary COMTRADE files, and when filtered data will mislead you.
- Fault analysis
How to Read a Fault Record: A Step by Step Method
A repeatable order of operations: verify the file, establish prefault, find inception, classify the fault, measure in a clean window, check direction, and read the clearance.
- Fault analysis
How to Identify CT Saturation in a Fault Record
The waveform signature of a saturating current transformer, the harmonic content that gives it away, and how to tell it apart from DC offset and inrush.
- Transformer protection
Transformer Inrush vs Internal Fault: How to Tell Them Apart
Both produce differential current. Waveform shape, harmonic restraint, and system context are what separate a magnetising inrush from a real internal fault.
- Frequency protection
Why ROCOF Relays Trip on Faults That Were Clearing Themselves
81R elements operate during unbalanced faults even when system frequency never moved. Why frequency estimation breaks down, and how to confirm it from a record.
- Tools
COMTRADE Viewers Compared (2026): Free & Paid Options
How Detego compares to SIGRA, TransView, and WaveWin for COMTRADE fault analysis, and where each one fits.
- Fundamentals
What is a COMTRADE File? Format Guide (IEEE C37.111)
What the CFG and DAT files contain, how the IEEE C37.111 standard is structured, and what a relay actually writes when it records a fault.
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Drop a COMTRADE file into Detego and get waveforms, phasors, and protection calculations without installing anything.
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