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 […]
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 fish tank. It is […]
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 […]
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 even rebuilt, a […]
Good Old, Quality H2O! Recently, the temperatures have been rather cold in the Washington DC area. We hit a week of temperatures below 20°F. Yes, I know; not very cold when compared to our northern states or Canada. But it still brought up some very good talking points. Do you test equipment below 0°C (32°F)? […]
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 are a cause […]
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 and […]
Transformer oil is a liquid 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 more compact than free air apparatus. […]
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 to vibrate. […]
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. Electromechanical Curve Shape […]