Category: GE

The Kelman DGA 900 PLUS is a member of the next generation of multi gas monitors. 

Built from the DGA 900 platform, the PLUS extends the monitoring capability beyond just DGA.

Knowledge of the condition of transformers is essential for all electrical networks and on-line monitoring

of transformers is an increasingly vital component of successful asset management programs.

The comprehensive information provided by the Kelman™ DGA 900 PLUS not only

allows expensive failures to be avoided but enables asset capabilities to be maximized.

The Kelman DGA 900 PLUS builds on the standard 9 gas DGA and moisture capabilities

of the DGA 900 by enabling the addition of extra sensors, electronic cards and firmware algorithms to expand its monitoring capabilities.

Bushing monitoring, partial discharge detection, OLTC monitoring, transformer models are amongst

the options available to offer an integrated system which delivers a more in-depth picture of

the transformer’s overall condition and will monitor the root causes of most transformer failures.

Benefiting from over 15 years of multigas DGA vendor experience and over 15.000 devices in the field,

the DGA 900 encapsulates learnings and improvements derived from its predecessors to bring improved performance,

innovative new features, enhanced user experience and increased field reliability and robustness.

While on-line DGA is now widely accepted as the most effective method of assessing the condition of a transformer,

it does not cover all the possible sources of issues.

In the early 2000’s, GE’s Kelman™ range of analysers brought consumable-free on-line multi-gas DGA to 

the market and GE is now proud to introduce the Kelman DGA 900, our next generation multi-gas on-line 

DGA and moisture analyser. At its heart lies an evolved implementation of GE’s proven Photo-Acoustic 

Spectroscopy (PAS) measurement technology, providing laboratory challenging levels of precision and 

repeatability with no consumables and no need for frequent re-calibration. Benefiting from over 40 years 

of global DGA vendor experience, the Kelman DGA 900 encapsulates learnings and improvements derived 

from its predecessors to bring improved performance, innovative new features, enhanced user experience 

and increased robustness.

Key Benefits 

 • Provides remote alert and multi-gas diagnostic of deteriorating transformer condition

 • Expedites operational decisions without needing to go to site for manual oil sampling

 • Issues can be detected in their infancy, avoiding unexpected failures and facilitating planned outages

 • Anchors condition based maintenance and asset replacement strategies on hard data

 • No need for consumables or frequent recalibration to operate at optimum performance

 • New “Rapid Mode” provides near real-time insight on fast developing faults

 • Enhanced computing power and scalable I/Os for a flexible transformer monitoring solution

 • Compatible with mineral insulating oils and newer ester based fluids (natural and synthetic)

Dissolved Gas Analysis (DGA) and moisture measurement of insulating fluids are recognized as the   

most important tests for condition assessment of transformers. In previous years, multi-gas DGA was 

traditionally confined to a laboratory environment, with infrequent off-line manual sampling forming part 

of time-based maintenance strategies. However, as the global average age of transformers continued 

to rise, the possibility of rapid ageing, unplanned outages and even catastrophic failure between off-line 

tests also increased, leading many asset owners to adopt on-line DGA monitoring strategies to increase 

network reliability.

Applications

The Kelman DGA 900 is an invaluable foundational tool for implementing Asset Performance Management 

(APM) across electrical generation, transmission and industry, enabling a condition based asset replacement 

strategy and delivering improvements in system reliability and availability.

A DS-Agile™ and Grid APM ready device, the DGA 900’s wide range of communication methods and 

protocols enables connection to those platforms and integration with GE’s Perception™ transformer fleet 

management software as well as other software, historian and SCADA systems.

All types of incipient faults are covered by the monitoring of hydrogen gas levels. Slowly eroding

paper faults can be exposed through the monitoring of carbon monoxide. Various degrees of thermal

faults, including arcing, can be detected and identified, often leading to a transformer repair rather

then a much more costly transformer rebuild.

In particular, the TRANSFIX DGA 500 enables the well known Duval’s triangle DGA diagnostic

described in Appendix B of IEC Standard 60599. It uses the value of 3 gases (Acetylene, Ethylene and

Methane) and is suitable for identifying various degrees/temperature of thermal faults as well as the

presence of high-energy electrical discharge faults.

Key Benefits

• Ability to perform Duval’s triangle DGA diagnostic

• Easily replaceable with a full nine gas unit

• Communicates data to allow remote diagnostic

• No carrier or calibration consumable gases required

• Available with AC or AC/DC power supply

Product Overview

The TRANSFIX™ DGA 500 is an on-line monitoring unit that measures individual dissolved gas and

moisture and provides both on-line monitoring and key exploratory diagnostics. It uses the now

well known PAS technology (Photo Acoustic Spectroscopy) made popular due to its accuracy,

repeatability and lack of consumable through its bigger brother the Kelman™ DGA 900.

When a transformer’s insulation system is overstressed, gases are produced that dissolve in the

transformer’s insulating oil. Dissolved Gas-in-oil Analysis (DGA) and moisture measurements are

recognized as the most important tests for condition assessment of transformers and the best early

indicators of developing faults.

Applications

Power Utilities

• Middle of the road solution for medium-criticality transformers

• Monitoring together with remote exploratory diagnostic

Industrial Plants

• Reduces the risk of process interruption due to power failure

• Minimizes costly production downtime

Controllers

The Hydran 201Ti can be connected to optional controllers to facilitate

communication with multiple units and create a local network.

• The Ci-1 controller is a one channel controller that replicates some of

the human interface functions (gas value display, alarm buttons). This is

ideal when the 201Ti is mounted out of reach on an upper valve of the

transformer. It also brings down the alarm relay contacts and the analogue

output for easier wiring.

• The Ci-C controller receives the gas ppm data from up to four 201Ti,

providing a single communication point for all four monitors. It has no

alarm relay or analogue output. This is ideal when protecting 3 single phase

transformers + 1 spare.

It is possible to “daisy-chain” up to 32 controllers or 201Ti through their RS-485

port. The maximum chain distance (all cables added up) is 1200m (4000ft). All

the 201Ti connected to any of the daisy-chained controllers can be accessed

through any controller in the local network, thus facilitating communication by

only having to fit one RS-232 modem for example.

Human Interface

• Backlit LCD display of gas information

• Keypad to stop unit and acknowledge alarms

• Compatibility with GE’s acclaimed Perception™

software to download, trend and analyze

transformer data

Mark IV Improvements

• Completely overhauled with improved sensor

durability, new electronic boards and power

supply to make it RoHS compliant while

increasing device reliability and capabilities

• Local USB port to replace the RS-232 port no

longer found on most field laptops

• Digital output of registers using Modbus®

protocol communication over isolated RS-485

Easy Asset Supervision

• Permanently mounts on a single transformer oil

valve. No extra piping or pump required

• “Composite gas” sensor responds 100% to

Hydrogen (general fault gas) and is also sensitive

to Carbon Monoxide (overheated paper)

Acetylene (arcing) and Ethylene (overheated oil)

thus covering main failure root causes

• “Hydrogen only” gas sensor is simpler and

responds 100% to Hydrogen gas only, the

general fault gas

Configurable Alarms

• An alarm is raised when an abnormal level of

fault gas is detected

• Two alarm levels (one for Alert and one for Alarm)

can be set to show increasing severity

• Alarms can be set on gas ppm levels or on gas

rate of change (ROC) over an hour or a day

• Automatic self-test every 15 days will trigger

service alarm if it detects a fault, including power

failure, oil valve closed, sensor or  battery needing

replacement

The 201Ti uses fuel cell technology (described as fixed instruments – method 3 in the standard) and is

now available with a choice of either the world renown “Hydran Composite Gas” sensor which responds

100% to Hydrogen and is also sensitive to Carbon Monoxide, Acetylene and Ethylene or the more basic

“Hydrogen Only” sensor which focuses purely on Hydrogen gas generation.

Because the monitoring unit mounts on a single valve and uses Dynamic Oil Sampling, there is no need

for a pump or extra piping to connect to different valves. Due to its uncomplicated features and the easily

understood information it provides, the 201Ti has been amongst the monitors of choice for many years,

with one of the largest installed base of any DGA monitor.

Key Benefits

• Continually measures key fault gas to give you an insight into the transformer’s condition

• Choice of gas sensor: traditional “Composite gas” or more basic “Hydrogen only”

• Communicates gas ppm and gas rate of change values remotely to avoid site visits and enable

remote supervision

• Fourth generation of this continuously improved design, with over 25.000 units sold worldwide

Essential DGA monitoring for transformers

Transformers are key and expensive components of the electrical grid and knowledge of their

health condition is essential to having a reliable network. When a transformer’s insulation system is

overstressed, gases are produced that dissolve in the oil. Dissolved Gas-in-oil Analysis (DGA) is recognized

as the best indicator of developing faults.

The Hydran™ 201Ti is a small and easy to setup continuous Dissolved Gas-in-oil Analysis (DGA) monitor.

It provides the basic information used by IEEE® Standard C57.104 and can be used as an essential first

line of defence for the transformers in your fleet to obtain advance warning of a failure condition and

minimize the risk of an unplanned outage.

Applications

Power Utilities

• Simple and effective solution for less-critical transformers

• Focuses and prioritizes asset replacement strategy

Industrial Plants

• Reduces the risk of process interruption due to power failure

• Minimizes costly production downtime