Worry-free DGA monitor commissioning is finally a reality

Optimus DGA Monitor bleeding air
Riku Rantala, Vaisala
Meet the expert: Riku Rantala
Application Manager
Published: Oct 2, 2019
Power Generation and Transmission

At Vaisala, as well as supplying world-class measurement equipment for monitoring transformer oil, we’re also here to make sure our customers can get the most out of their monitoring equipment and help take the stress out of getting it up and running.

Air bubbles in insulating transformer oil can cause serious problems, such as electric discharges or triggering the Buchholz relay and stopping the whole transformer. So when installing and commissioning measurement equipment in a transformer it’s important to take care that no air bubbles are introduced into the system.

The Vaisala Optimus™ DGA Monitor OPT100   has a number of unique features that provide clear benefits in this regard. Here are three questions we’re often asked – if you have any questions of your own, get in touch and we’ll be happy to answer them!

Do I need a separate vacuum pump?

When we’re discussing OPT100 installation with customers, they often ask if it needs a separate vacuum pump. People are often surprised when we explain that it doesn’t: isn’t there a big risk of air bubbles getting into the transformer oil when the valves are opened and the pipelines are full of air?

The answer is no: the Vaisala OPT100 is equipped with a powerful integrated vacuum pump that creates enough pressure to separate the gas from the oil as part of its measurement cycle. The pump also plays a significant role when commissioning the unit.

Combined with the hydrostatic pressure of the transformer, the pump removes air through its release valve and fills the system with oil (as illustrated in image). Using multiple sensors, the OPT100 makes sure that the transformer’s oil tank is always at a higher pressure than the instruments at the end of the pipeline. Forced by the laws of physics, air and oil flow away from, rather than into, the transformer tank.

Do I need specialist assistance to bleed the OPT100?

Again, the answer is no: the bleeding process is extremely user friendly and fully automated – we’ve designed it so it can be done by anyone, and no special tools or training are needed. To start, simply click a button on the web-based user interface, remove the bleed plug, and open the valves when told to do so. The system will automatically ensure that every pipe and cavity is filled with oil and the air removed before continuing to the next step. The OPT100 uses high-end level detectors, automatically controlling the pump and valves to stop oil intake when the liquid level is correct – meaning not a single drop of oil will spill out from the release valve. The OPT100’s safety features include comprehensive self-diagnostics, so the system will automatically inform you if you forget to carry out any necessary action or if anything needs your attention.

Compared to traditional DGA installations, the time and cost savings are remarkable. You don’t need to schedule installation based on the availability of a specialist and there’s no need to invest in special equipment. Once you have started commissioning in the user interface, online measurement can usually begin within an hour. After that, you can relax and the Optimus™ DGA Monitor will take care of your online monitoring.

How easy is it to install an online monitoring instrument into a power transformer?

With the OPT100, the answer is very easy. The instrument is designed to make installation quick and super simple – just connect the oil, power, and data connections and it’s ready to go.
Watch this real-life installation into a live power transformer to see for yourself.

Read more about the  Optimus DGA Monitor OPT100

Watch the video: Maintenance-free monitoring with the Vaisala Optimus DGA Monitor OPT100




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