Transformer Oil – What is it, and why sample?

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. […]

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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 to vibrate. […]

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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. Electromechanical Curve Shape […]

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How to Determine Distance for Ground Resistance Testing

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 […]

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Torque – Does it matter?

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 […]

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5kV Chiller Starter – Washington DC

The photo above is the actual faulted starter. Take notice of the 3- tan fuses and how the white leads are jumpered. The tan fuses are the main fuses into the starter. The white leads jump voltage from the bottom of the fuse, to the top of the vacuum contactor. Contactors are a set of […]

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The Importance of Battery Maintenance

If you refuse to do battery maintenance, or don’t believe in maintenance at all, think again. These batteries were installed in 2006. Loose connections and lack of proper fluid levels attributed to the degraded condition. In most cases, batteries are a critical part of your electrical system and are over looked the majority of the […]

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