SOE
Sequence-of-events recorder
Recorder that timestamps changes of state on many binary inputs so the order of operations can be reconstructed.
Schematic
Symbols · DFR
Disturbance recorder
Recorder that captures analogue waveforms and binary signals before and after a trigger for fault analysis.
In plain English
What does Disturbance recorder mean?
A disturbance recorder captures sampled current and voltage waveforms together with breaker and protection contact states when a trigger occurs. Pre-fault and post-fault data let engineers check how protection performed, so the recorder is drawn with its analogue inputs from CTs and VTs and its binary inputs from trip and position contacts.
A simple example
Many protection relays now include this function, so a separate recorder symbol usually indicates a dedicated substation-wide unit. The symbol does not show trigger conditions, sample rate or record length, and records are commonly exchanged in a standard file format that should be named in the specification.
What the drawings help you do
Trace analogue inputs to their CTs and VTs. List binary inputs and their sources. A disturbance recorder stores high-rate waveforms around an event; a sequence-of-events recorder stores timestamped contact changes only.
This particular reference
Recorder that captures analogue waveforms and binary signals before and after a trigger for fault analysis. A disturbance recorder stores high-rate waveforms around an event; a sequence-of-events recorder stores timestamped contact changes only.
- Normally open / normally closed
- The contact state in the normal condition defined for the drawing.
- Coil
- A wound conductor that can produce a magnetic field when energised.
- Signal
- Electrical information passed between devices, rather than necessarily the main power supply.
Read the source: Relion 620: functions, codes and symbols · PowerLogic ION9000 user manual
SLD / Schematic · DFR
What it represents
A disturbance recorder captures sampled current and voltage waveforms together with breaker and protection contact states when a trigger occurs. Pre-fault and post-fault data let engineers check how protection performed, so the recorder is drawn with its analogue inputs from CTs and VTs and its binary inputs from trip and position contacts.
Many protection relays now include this function, so a separate recorder symbol usually indicates a dedicated substation-wide unit. The symbol does not show trigger conditions, sample rate or record length, and records are commonly exchanged in a standard file format that should be named in the specification.
How to read it
- Trace analogue inputs to their CTs and VTs.
- List binary inputs and their sources.
Information to show or reference
- List analogue channels
- List binary channels
- State trigger and record length
A distinction that matters
A disturbance recorder stores high-rate waveforms around an event; a sequence-of-events recorder stores timestamped contact changes only.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Relion 620: functions, codes and symbols
Public relay function list including disturbance recording within protection IEDs.
PowerLogic ION9000 user manual
Public meter manual describing measurement, logging and recording features of a revenue and power-quality meter.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
Explore related references
IED
Numerical protection relay (IED)
Single relay block on an SLD that lists the protection functions it provides, with CT, VT and trip connections.
SLD / Schematic
OSC
Oscilloscope
Instrument that displays the waveform of a signal against time, drawn with a waveform inside the instrument outline.
Schematic
Put the reference into a drawing workflow.
Elora Grid helps electrical teams work with drawings, specifications and equipment information. Explore the drafting workflow or join the early-access waitlist.