Where do you rent your electrical test equipment? Oftentimes, you may not have a test set that you may need. There are multiple reasons why this may be the case. Those of us who regularly work in the electrical testing field, know how expensive equipment is. A primary current injection test set may sell […]
Familiarity with insulating oil features can really set you apart from your competition! Utilizing a few of your human senses, can be a crucial part of diagnosing equipment. […]
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)? […]
Do you make your own test boxes? Test boxes can be made for a variety of reasons. They are typically home made boxes that help to make manipulating voltage a little more usable for a specific task. They are usually not sold by a manufacturer because the market or target audience is extremely small. There […]
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 […]
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 […]
This topic can be extremely complicated. So here is a quick run down. Many people often ask, “how far out do you need to run leads to the furthest rod?” This is not a linear calculation. If you are talking about a grounding delta that is 10′ x 10′ x 10′, you could be running […]
Does torque matter? The short answer, absolutely! Most electricians don’t realize that a bolt and nut is not a means for AC Current to flow through. The actual resistance of the bolt is a much higher resistance that the resistance of two sandwiched pieces of copper. When a bolt is torqued to spec, it firmly […]