Tag: maintenance

Why is NETA important?

Many people do not know what NETA is. Before I can explain my views of NETA, the following statement is directly from NETA’s website. What is NETA? The InterNational Electrical Testing Association (NETA) is an organization that serves the electrical testing industry by offering accreditation of third-party electrical testing firms, certifying electrical testing technicians, producing […]

Sulfur hexafluoride

Sulfur hexafluoride (SF6)   What is SF6? It’s an inert, colorless, odorless and non-flammable gas.  Sulfur hexafuoride is about 5 times denser than air, meaning it’s heavier. If you were to fill a fish tank with SF6, you could treat the gas as if you were pouring water into a fish tank. It will collectively stay within the […]

General Electric 15kV MagnaBlast

The power company, or you, decide you need to de-energize a circuit. You rack out and remove your trusted 1960’s vintage breakers, of course you are suited up in the proper level PPE (Personal Protective Equipment). You then dust off your vintage ground and test device and install it in the cubicle. Connect the motor […]

The Importance of Acceptance Testing

Acceptance Testing   Before we can begin to talk about “Acceptance Testing”, you may or may not understand the phrase. Acceptance Testing pertains to all new electrical components. These are either purchased from a distributor, or even a manufacturer, but have never been put into “service”, i.e. energized. When a building is being remodeled, or […]

Transformer Snubber Assembly

What is a Transformer Snubber?   It is a set of capacitors, surge arresters, fuses, and resistors typically found on medium voltage dry type transformers.   What are Snubbers designed for?   The main application has been to reduce damage to transformers during energizing applications. Energizing medium voltage transformers produces transient voltages. These transient voltages […]

General Electric Multilins Protective Relaying

Multilins SR745 & SR750 Model Power Supply Issues:   Recently, I have been tasked to perform some relay testing on multiple General Electric SR relay models. But in particular, the issues experienced have been with the original model SR745 (Transformer Protection Relay) and the SR750 (Feeder Protection Relay) models. Here are examples of the Original […]

Transformer Oil Samples

Transformer oil – what is it?   Transformer oil is an oil that is stable at high temperatures and has excellent electrical insulating properties. Typical motor oil that most people think of, is not the type of oil in a transformer. Transformer oil keeps the transformer cool. It also insulates the transformer and allows electrical components to be […]

Electromechanical Relay – Contact Cleaning

Electromechanical Relay – Contact Cleaning   Equipment owners often wonder the importance of maintenance on any variety of equipment. Some owners would even say that electrical maintenance is a waste of money. I have a demonstration of an electromechanical relay with dirty contacts.   When watching the video, notice the contact below the coil begins […]

Electromechanical Relay – Basic Operation

Electromechanical Relay Operation – Above is a brief video of an electromechanical relay operating at 3 different fault magnitudes. These fault magnitudes are based off of the relay setpoint – 200% fault, 400% fault, and 600% fault. The relay set point is based off of the CT ratings and the bus/cable/load ampacity ratings.     […]

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