They may not get a lot of attention, but transformers are a vital part of every facility — and, like a lot of important equipment, they have a lifespan that shortens or lengthens based on how they’re maintained. Just like you go to the doctor for regular checkups and blood work to keep your body well, so to your transformer needs regular reviews and testing in order to stay in good health. When it comes to transformer maintenance, there are a lot of different tests you can perform today. Recognized standards like NETA, ANSI, IEEE and others help dictate what makes a transformer resilient and safe, and tests can reveal underlying problems that don’t meet those standards.

Designed to reveal issues that will require power transformer maintenance, transformer analysis testing helps you to stay on top of upkeep and repairs, extending the length of your equipment.

What Goes into Transformer Maintenance
Routine transformer maintenance will cover a variety of factors, from cleaning to testing, including:

  • Cleaning of components
  • Oil analysis and testing
  • Other tests (i.e., power/dissipation factor, transformer turns ratio, winding resistance predictive measurements)

The idea behind these tasks it that proper care reduces the risk of failure and improves reliability. Conducted by trained field technicians and engineers, transformer maintenance services help to identify leaks and extend the transformer’s life.

How Transformers Are Tested
Oil-fill transformers have oil in their tanks to insulate the electrical components, which also helps keep the windings cooled. So to test transformers, you send a sample of that oil off to a laboratory where experts run a series of tests with different types of chemicals to identify contaminants, moisture content, combustible gasses and how the oil reacts to different types of voltage. They also use a gas chromatograph to test for contaminants.

Why Transformers Are Tested
A lot of people look at transformers like they’d look at the lights in their houses — as long as things are working, everything must be fine. But the problem is that transformers are not like changing the oil in your car or knowing the lights are on. Even when things appear okay, there may be problems going on underneath the surface.

What Testing Does and Doesn’t Reveal
While transformer oil testing is vital for transformers, it’s not all-inclusive. Still though, while the typical test does not give you complete and comprehensive information about anything that could ever go wrong with the transformer, it does provide some key baseline details. What you’ll learn is the transformer’s status (i.e., are there combustible gases? Is there an air gap that needs to be filled with nitrogen? How likely is it that this transformer could explode?). Finding out if it could explode is especially important, as explosions can injure workers and destroy equipment.

  • Combustible Gases: If there are combustible gases within a particular oil sample, that doesn’t necessarily mean there’s a problem. What it means is there’s something to watch and pay attention to. Through repeated testing over increments of time, you’ll know if there are escalations in the combustible gases, which tells you there’s probably a short of some kind going on.
  • Air Gaps: Typically when there’s an air gap within a transformer, it’s at the top, and it will need to be filled with nitrogen. This is because you don’t want oxygen to get inside. If oxygen does get into your transformer, you can build up combustible gases and the transformer can potentially explode.

Heat and Transformers
Interestingly, transformers in particularly hot regions of the country sometimes have a shorter lifespan than those in cooler areas. This is because the biggest killer of transformers is heat. If you have a transformer that’s heavily loaded and sitting in a shaded area of 105° to 115°F, for example, you can easily wind up with a problem fast. Some transformers do have external radiators, and some have fans, but any way you can dissipate the heat is helpful.

Even though you might not realize it, transformers are a crucial part of every facility — and they’re a sensitive part of it, too. Even a small amount of moisture within a transformer’s oil can end its lifespan, and leaks usually indicate moisture issues. In order to keep up with industry standards and protect your equipment, it’s important to conduct regular, consistent maintenance on transformers. By practicing regular oil testing and component cleaning, you set your transformer up to last a long while.