• Overview

• By Category

• By Product
• Dielectric Fault Analyzer DFA100
• Doble Delphi
• Doble Test Assistant Software
• DOMINO Sensor
• F Protection Series
• Intelligent Diagnostic Devices
• Leakage Current Monitor
• M4000 Series
• M5000 Series
• Partial Discharge Detection
• ProTesT software
• TDR Series

Dielectric Fault Analyzer DFA500

Doble's New Tool for Gas Insulated Substation, the world’s first portable multichannel acoustic analyzer including UHF sensing.

The DFA500 Dielectric Fault Analyzer is a portable, battery-powered instrument for measuring non-intrusive, in-service acoustic signals and radio frequency interference (RFI) in the UHF (ultra high frequency) band produced by partial discharge and loose components. The DFA500 is designed for in service surveys to detect faults in grounded SF6 gas-insulated substations (GIS). The new DFA500 from Doble is unique for GIS applications as it is equipped with 4 acoustic channels, one UHF channel and wireless or wired synchronization with the power frequency.

The DFA500 can be applied to any grounded component associated with the SF6-filled apparatus under test. During acoustic emission measurement, the DFA500 processes the results and produces a signature which eases the identification of the fault. The instrument will produce signatures that differentiate between PD, particles, and mechanical defects.
In addition to multiple channel acoustic solution and introducing UHF sensing, the new development offers better sensitivity and accuracy. Trigger functionality by UHF, acoustic or utility frequency gives added value to flexibility for operators.

Features and Benefits

• Condition-Based Monitoring. Use for GIS, SF₆-filled dead-tank breakers, and instrument transformers, during commissioning and in service. Identify and locate PD, particles, and mechanical defects.
• Rapid Results. The DFA500 is quick and easy to configure, producing results in seconds. Use the results by themselves or in conjunction with other in-service test results to assist decision making.
• Selectable Settings. The DFA500 provides five different modes for analysis; oscilloscope, bar graph mode, phase resolved mode, time of flight mode, and location mode.
• Simple, User-Friendly PC Interface. Use the simple interface to upload test results to a PC or download previous data and nameplate configurations.
• Rugged and Reliable. The DFA500 has outstanding durability for field use and produces high-quality results with high repeatability, allowing for rapid and reliable decisions..
• Battery Operated. The DFA500 is a standalone, portable instrument that can operate up to 6 hours on one charge.
• Wireless Synchronization. The DFA500 uses a wireless synchronization module for timing PD and mechanical activity against the power system frequency.

Different operation modes:

• Use Oscilloscope to view real time input from the active sensors and the UHF input channel.
• Use Continuous mode to survey apparatus and locate the primary source of the AE signal. Continuous mode provides four scales of acoustic signal measurement: the RMS signal, peak signal, degree of modulation with fundamental, and degree of modulation with second harmonic.
• Use Phase mode to correlate the acoustic signal and the fundamental power signal and generate an amplitude vs. phase plot. This information is used to determine the synchronizing nature of the acoustical discharges relative to the fundamental power signal. The patterns obtained are used to identify the nature of the source: PD, particles, and mechanical defects.
• Use Pulse mode primarily to monitor particles. Particles are dynamic and produce both electrical discharges and mechanical impacts. This dynamic behavior is best represented in Pulse mode, in which DFA500 displays the results in an amplitude vs. elevation time plot. This information can be interpreted to determine number, size, and severity of the active particles.
• Use Location mode to locate failures by using one acoustic channel as reference and measure the time difference from source to another sensor (up to three others) to pinpoint location of failure.

DFA500 Viewer Software

The DFA500 comes with the PC software DFAViewer that allows you to:

• Manage DFA500 results
• Plot and overlay results
• Compatible with DFA100 results
• Upload and download data to the DFA500
• Generate detailed reports
• Upload data to DTAWeb