Qualitrol has tons of products to help you properly monitor your Vault Transformers. Dissolved Gas Analyzers, Intelligent Monitors, and Temperature Gauges are some of the ways to maintain your assets. You can learn more about Vault Monitoring with Qualitrol by clicking this link, https://www.qualitrolcorp.com/assets/vault-transformers/

1. Vault Monitoring Webinar
Starting at 11am Eastern Time

2. Speakers
Donal Skelly- Product Manager; Serveron DGA Instrumentation
Donal has worked in the field of dissolved gas analysis (DGA) and its associated
instrumentation for 15 years. His career focus to date has been on analytical
instrumentation, product and market development for online DGA monitoring.
Donal holds a Bachelors of Science Degree (Honors) in Industrial Environmental
Science and Post Graduate Diploma in Renewable Energy Systems out of Institute of
Technology in Ireland.
Leon White – Midwest US Sales Manager – Qualitrol
After working in substation design for a large electric utility, Leon has been working
with transformer monitoring and DGA for the past 10 years. Leon has been with
Qualitrol for 5 years and works with substation monitoring solutions.
Leon holds a Bachelors of Science Degree in Electrical Engineering and Masters in
Business Administration from Southern Illinois University at Edwardsville. He is also a
registered Professional Engineer.

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6. Monitoring in the Vault Space
1. How online monitoring can increase vault safety and reliability.
2. DGA in Vaults
DGA150 ITM509 QTMS

7. What's in an Underground Vault?

8. Why Monitor?
For most utilities there is a compelling need to:
• Replace scheduled maintenance with predictive maintenance => Condition Based Maintance (CBM)
• Minimize costs to maximize asset ROI
• Increase safety to both public and utility personnel
– Communities will not tolerate safety issues nor tolerate service disruptions / Media & political pressure
– “If a transformer fails, I hope it fails quietly”
Increased “monitoring” provides for all of the above and offers protection against
unexpected failures

9. Failures at any point in the transformer lifecycle have major consequences for a utility
Some of these are:
– Capital replacement costs $$$$$
– Cost of purchased power $$$
– Cost of lost capacity $$
– Cost of added stress on other equipment $
– Potential fines for service interruption $
– Public perception $
– Environmental consequences $$$$
Source : CIGRE WG B3.12 Obtaining Value from On‐Line Substation Condition Monitoring
Cost of Failure

10. Question : How can end of life be managed?
• On-line monitoring plays a beneficial role in both classifications – Warn and Inform
• On-line instruments continuously monitor the condition or health of the
transformer, providing early warning of incipient faults.
• DGA can be used to identify normally aging transformers approaching end-of-life
and DGA enables planned replacement.
All have an ‘end of life’!
2.
Unexpected, possibly catastrophic
failure, sudden or slowly progressing
1.
Managed life-cycle, where aging
assets are replaced prior to failure

11. Vault Transformers
Cramped!
Dirty & water filled!
Downtown!

13. What Can Be Monitored?
Main TankSwitching
Compartment
25
Liquid
Level
HI
LO
25
Liquid
Level
HI
LO
PRD
DGA150
• Oil Level
• Oil Temp
• Tank Pressure
• PRD Status
• Hydrogen
• Ambient Temp
DGA150

14. Simple Gauge Replacement
Oil Level Gauge
Before After
Temperature Gauge

15. Typically for marine applications we see many utilities use our range of products for
vault applications.
Qualitrol comprises a large range of sensors, including DGA sensors in a high grade stainless
steelhousing.

17. • DGA is the monitoring of gases produced in transformer oil
• Insulating materials (oil and cellulose) within transformers
break down to liberate gases
• If monitored the distribution of these gases can be related
to the type of electrical fault
• The rate of gas generation can indicate the severity of the
fault
• Even healthy transformers produce some gas
• DGA is proven to be a reliable diagnostic technique for the
detection of incipient fault conditions within liquid-immersed
transformers
The early warning provided by
DGA monitoring allows the user
to plan corrective actions where
possible.
What is DGA?

18. DGA is measurement of key fault
gases:
• HYDROGEN (H2)
• methane (CH4)
• acetylene (C2H2)
• ethylene (C2H4)
• ethane(C2H6)
• carbon monoxide (CO)
• carbon dioxide (CO2)
• oxygen (O2)
What is DGA?
Hydrogen is formed in
abundance under many
types of fault conditions
Including:
• Partial Discharge
• Hot spots
• Arcing
• Production of other fault
gases largely dependent on
temperature profile and type

19. • Online monitoring of hydrogen levels establish a baseline for the individual
transformer and can send an immediate warning when conditions start to
change.
» Rate of Change (ROC)
• Measured Hydrogen concentration indicates the severity of the fault and so
drives the urgency of remedial action.
» Parts Per Million (ppm)
H2 Why Hydrogen?This Photo by Unknown Author is licensed under CC BY-SA This Photo by Unknown Author is licensed under CC BY-NC-ND

20. Why Hydrogen?
Hydrogen Trend
PPM
High
Rate of Change
High
Rate of Change
PD Arcing

21. IEEE - Std C57.104-2008: IEEE Guide for the Interpretation of Gases Generated in Oil-Immersed
Transformers
This standard establishes a four level set of criteria to classify risks to a transformer when there is no
previous dissolved gas history.
How Much H2?
Condition / Concentration Action
Condition 1: 100 ppm Hydrogen levels exceeding 100 ppm should prompt additional investigation.
Condition 2: 101-700 ppm
Action should be taken to establish a trend (see the standard for additional details).
Fault(s) may be present.
Condition 3: 701 – 1800 ppm
Immediate action should be taken to establish a trend. Fault(s) are probably
present.
Condition 4: > 1801 ppm
Continued operation could result in failure of the transformer. Proceed immediately
and with caution.

22. IEC 60599 - Mineral oil-filled electrical equipment in service - Guidance on the interpretation of
dissolved and free gases analysis
• Three Criteria described :
1. Typical rate of Hydrogen gas increase for transformers is <5 PPM per day
2. An increase in gas concentrations of more than 10% per month above typical concentrations is generally
considered a prerequisite for pronouncing an active fault is present
3. Significantly higher rates of gas increase, such as 50% per week, are generally considered serious,
especially if they exceed alarm concentration values
What about Rate of Change?

23. DGA Monitors
DGA 150
Drain Valve – 1.5” NPT Union
Fitting
Thread mount
DGA 250
RPRR – 2.5” NPT Union Fitting
Thread mount
Hydrogen DGA Sensor
DGA 400
RPRR – Flange Mount
Headspace or Oil phase
measurement options

24. How is the H2 Measured?
H2
Pd Pd
H2 from the oil enters the Pd lattice
The amount of H2 in the lattice is proportional to the
concentration of H2 in the oil
• When H2 enters the Pd lattice, the electrical properties of
the lattice change. The change in electrical potential is
translated into PPM of H2
H2
Membrane
Solid-State,
Palladium Sensor
Sensor is directly immersed in oil
• Good reliability
• Simple design
• 100% resistant to vacuum

25. How does gas get to the sensor?
Transformer

)))
)))

❶ Convective thermal currents mix gases in
transformer
❷H2 movement in drain valve piping driven by
diffusion and vibration
NOTE: What if you’re monitoring the headspace?
Gas migrates from the oil into headspace and can be
measured there.

26. DGA150 and Qualitrol ITM 509
Some of the many configurable outputs from the ITM 509 based on data from DGA150
Last reading Displays the latest hydrogen measurement from the DGA sensor in PPM
Today’s average The average hydrogen value for the present calendar day, in PPM
Today’s min The minimum hydrogen value read for the present calendar day, in PPM.
Today’s max The maximum hydrogen value read for the present calendar day, in PPM.
Min X days ago The minimum hydrogen readings for the past twelve calendar days
Avg X days ago The average hydrogen values for the past twelve calendar days
Max X days ago The maximum hydrogen readings for the past twelve calendar days
History Graph History Graph window which displays the minimum, average and maximum hydrogen readings
for the past twelve days

27. • You can improve the reliability and safety in the vault by having a constant
window into transformer health status
• ITM 509/QTMS are excellent platforms from which to monitor a range of
sensors in the vault
• The advanced DGA150 sensor interfaces easily with ITM/QTMS to provide
advanced warnings of aging or fault detection
– Qualitrol DGA150 is fully submersible for the vault space
Key Take Aways

28. Thank you!