LumaSense SmartDGA, Hardware Manual

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SmartDGA Hardware Manual System Overview
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2 System Overview
The LumaSense SmartDGA ® system was
designed with the environmental
conditions of a transformer substation in
mind and utilizes a specially constructed
Non-Dispersive Infrared Sensor (NDIR)
detection system to measure fault gases.
LumaSense offers three SmartDGA
Instrument models: Gauge, Guard, and
Guide.
A SmartDGA system includes the instrument
itself (Gauge, Guard, or Guide), necessary
mounting hardware for a transformer
single or dual valve mounting or an inline
adapter mounting which can be applied to
a transformer or a LTC filtering system,
power and/ or + I/O connection cable to an
EZHub device, and an optional LumaSMART
i Core which contains the SmartDGA Viewer
software. Installations can be accomplished
within hours (less than 4 hours in most
cases) and requires no carrier gases,
consumables, or scheduled calibration.
The SmartDGA EZHub has a battery backed-
up Real-Time-Clock-Calendar (RTC). The RTC allows the EZHub to be programmed to report
measurements at a selectable rate. The first measurement cycle can be programmed to start at a
specific time of day. The rates that can be programmed are: 3 hours, 6 hours, 9 hours, 12 hours, 24
hours, 48 hours, and weekly.
When a measurement cycle starts, the LumaSense SmartDGA ® instrument flushes the old oil within
it and returns it to the transformer and/or LTC. The instrument then pulls a fresh oil sample to run
the measurement cycle and uses a membrane gas separator to extract a sample of the dissolved
gases from the transformer oil. The instrument measures the dissolved gases using an NDIR gas
sensor. After the NDIR measurement, the gas sample is sent past the oxygen and hydrogen sensors
to determine those gas concentrations. Oxygen and hydrogen cannot be measured by (non-
dispersive) infrared spectroscopy, but instead are measured using sensors which consume oxygen
and hydrogen, which is why it is done as a single step at the end. The instrument also performs a
background gas measurement which serves as a reference measurement. The SmartDGA system
collects the results of each gas analysis cycle and stores the data in memory within the SmartDGA
EZHub controller.
At the end of each measurement cycle, the EZHub stores the results on the internal memory and
sends them to the DGA Viewer software. The EZHub can also be configured to give an indication of
the fault condition in the oil by comparing the gas results to programmable thresholds for the gases
in level, rate, and ratio. The indications and conditions are:
GREEN Normal
YELLOW Caution
BLUE Warning
RED Alarm