MA-025
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DGA 900 Operator Guide
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Rev 2.0
12-Apr-19
Page 8 of 92
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Advanced high precision Photo-Acoustic Spectroscopy (PAS) sensing technology based
on a robust multi-point individual gas calibration process using certified gases to
calibrate the PGA (Photoacoustic Gas Analyser).
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Complete multi-gas analysis (nine gases and moisture) with a user-configurable
sampling frequency from once per hour to once every four weeks including remote alert
capabilities. All gas sensing is carried out internally without a need for carrier gases or
recalibration. Minimal maintenance
*1
and no requirement for costly consumables.
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A new ‘Rapid Mode’ allows
sampling to be completed in around 30 minutes using five
key gases and is useful in critical situations to give immediate insight on fast-developing
faults.
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Improved lower detection limits and measurement repeatability for earlier detection of
imminent faults on the transformer being monitored.
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Transformer load tracking (CT analogue input as standard).
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Watchdog relay as standard to monitor power usage.
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Six configurable relay contacts based on absolute gas and moisture values (with one
dedicated service).
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Five optional 4-20 mA configurable analogue input cards.
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Three digital inputs (optional configurations available).
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Compatible with AC or DC power.
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Four sunlight-visible LED arrays on the exterior of the Hub module
—
red for alarm,
yellow for caution (both user-configurable)
—
and green for power, blue for service.
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A fully embedded microprocessor with 4 GB non-volatile internal memory storage,
highly scalable analogue and digital I/Os, an embedded webserver, 8 GB SD card to hold
measurement data and an integrated 7 in. colour LCD screen with resistive touch for
simplified local user interaction and visualization of data.
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The infrastructure provides a platform for expansion and future feature enhancements
complemented by an extensive range of secure communications options. These include
Ethernet, RS-485, cellular modem (SMS Text Alerts /GPRS), and fibre optic options
(IEC61850 or DNP3). Internal USB connection is provided for commissioning and service,
or local data download. Other options may be available on request.
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Compatibility with GE’s Perception transformer fleet management software for data
download, trending and analysis as well as other SCADA systems. The product is a DS-
Agile and Predix-Grid APM ready device with support for industry standard protocols.
*
1
Note: The only recommended maintenance is periodic cleaning of the air filters, in-line
oil filter and battery replacement.