By Ron Nicholas, VP & GM - Switchgear & Field Services
With new equipment replacement cost and lead times at an all-time high, it is essential that your existing equipment be properly maintained. Preventive maintenance, when performed annually, can ensure equipment performance, reduce the need for future maintenance, and can increase the service life of your equipment while preventing costly outages and failures. There are many tests that our SWE experts use in our overall evaluation process. Below, I will be discussing the various maintenance test categories and why they are conducted. Bear in mind that applications of these tests may vary depending on equipment.
Routine Testing
Insulation
Insulation is an important aspect of the equipment within your substation. Insulation ensures that all the electrical components are safely isolated, reducing the potential for accidental contact & minimizing failure risks. Insulation testing gives technicians the ability to prevent issues within the equipment that may arise due to deterioration from moisture, thermal aging, and contamination by dust and debris. By conducting these tests, we can identify and address any of the previously mentioned safety concerns. This will in turn extend your equipment’s lifespan while maintaining efficiency through the mitigation of energy loss within the equipment. Listed below are a few of the different insulation related tests that can be run.
- Power factor – bushings
- Power factor – windings
- Degree of polymerization (DP)
- Insulation resistance (megger) –winding Insulation
Windings
Windings allow for conversion and transfer of energy within your equipment and across your entire substation. By routinely testing your winding and checking the current pathways within the transformers to ensure they are solid, you can reveal loose connections and faulty equipment. In addition, the tests help to determine that no windings or conductors have shifted. Testing these components helps reduce the risk of outages while maintaining a reliable power supply. Below are a few different windings tests technicians can run that will help diagnose any winding related problems your transformers may encounter.
- Transformer turns ratio (TTR)
- Winding resistance
- Single phase excitation
- Sweep frequency response analysis (SFRA)
Current Transformers
CTs allow you to properly monitor and control your system of equipment. Being able to ensure that your CTs are providing accurate readings allows them to continue to protect your system through the detection of issues within your equipment. Testing these systems helps to detect things such as degradation issues, faulty connections, and false monitoring or measurements. When your system is providing proper readings, it creates ease of mind with regards to your transformer’s functionality and safety. Listed below is one of the important types of CT testing that our technicians here at Southwest Electric conduct to ensure operational reliability.
- Current transformer (CT) – ratio, polarity, and CT saturation
Controls & Monitors
Having the ability to receive real time data on the status of equipment at your substation allows you to immediately detect issues when they arise. These systems allow for the minimization of downtime while also preventing issues from causing extended outages and damage. Having accurate real time data is important for knowing what parts of your station will need maintenance and how to properly navigate downtime. Lack of testing these systems could result in inaccurate data and unpredictability within your substation. Below are a few of the variety of tests that we run to ensure your equipment is providing you with accurate data and doesn’t run into any issues.
- Control verification
- Protection verification
- Function testing – tests protection, automation, and control systems
Fluids
Your team’s ability to keep your fluid quality in tip top condition can mean the difference between your transformer’s operational longevity, and them running into issues. Testing the fluid quality allows technicians to detect contaminants and ensure fluid is sufficient to prevent electrical issues. This results in operational efficiency, dielectric strength, and proper cooling. Listed below are just a few of the tests that can be used to evaluate your substations fluid quality.
- Dissolved gas analysis (DGA)
- Moisture content
- Dew point
- Leak detection
Breakers
Breakers protect the system and equipment from damage caused by overloads or short circuits. Testing verifies the operational reliability and determines if functionality has been impacted by age or wear. Conducting routine breaker tests helps to determine the correct operation of settings for the trip unit on designated circuits. Thorough testing can end up saving your equipment from damage that might lead to failure.
- Primary and secondary injection testing
- Mechanical function
- Anti pump functions
- Megger insulation testing
- Contact resistance testing
- Timing and motion
Conclusion:
Not only does routine maintenance improve the performance of your equipment, it also leads to increased efficiency, extends the life of your gear, and improves safety. Our team at Southwest Electric are experts in this business space and working directly with clients to customize practical maintenance solutions/programs for both in-service equipment and out-of-service equipment (spares, stock, etc.).
Our field operations team is well versed in the scheduling, execution, and follow-up visits as defined in each customized maintenance program. Our service crews and equipment can be dispatched at a moment’s notice should an emergency arise, and field support is required.
In some cases, you may already have a maintenance program in place that works well for your business and just merely need support in performing the work, and SWE can provide support as required should this be the case.
Southwest Electric Co. can run all the tests outlined above. The interpretation of the data is a critical aspect of our process, and our SWE experts are fully fluent in reviewing the data and preparing written recommendations/solutions for any deficiencies that are identified to keep your equipment in good operational condition.
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Looking to find out what it takes to keep your operation up and running? Check out some of our previously articles and videos by clicking the links below!
Maintenance Strategies: A Step-by-Step Approach (swelectric.com)
The Importance of Electrical Testing Your Transformer – Southwest Electric (swelectric.com)
Transformer Oil: Everything You Need to Know – Southwest Electric (swelectric.com)