Figured this one would interest the general engineering audience:
Fixing a 7,000-Ton Drill
A 7000 ton tunnel boring machine nicknamed "Bertha" has been stuck under downtown Seattle since last December after it struck a pipe and a seal failed. Work is under way to enact a fix: a vertical shaft...
What guidelines do you follow for the proper installation of a core-balance CT in MV (~4kV) environments? I appreciate the general advice of centring the phases in the window, using the smallest window possible, twisting the secondary wiring, maintaining separation between CTs and sources of...
I've come into possession of a GAI-Tronics GM1004 ArcTrap. It's a two terminal device that looks like a big toroidal inductor and is designed for use in earth fault protection networks. I'm trying to characterise it and coming up with very confusing results. I've done a frequency sweep, an...
I've recently taken some CRO readings of a transformer secondary during operation of a circuit breaker on the primary. The resulting voltage transients are causing problems in the field, but I don't have enough experience in this area to know whether the results are typical.
Transformer is...
I'm shopping around for a platform to base a new product of our design on. The product at its heart must autonomously sample and store a number of voltage signals. In this case, the less custom development (hardware and software) the better, so we're willing to pay for off-the-shelf gear. I've...
This question doesn't neatly fit into electromagnetism, antennas, circuit design or power engineering but probably requires knowledge from all fields. I keep coming back to this seemingly simple question and never leave quite satisfied...
A non-contact voltage probe, aka a voltage stick, when...
From this site and other sources, I've come to understand that semiconductive screens in cables are generally used in medium and high voltage transmission and distribution applications. There they reduce uneven capacitive voltage distribution by providing a relatively low impedance discharge...
A CT is traditionally used to measure AC currents. Technically however, a CT is sensitive to DC as well but typically the core will become saturated quickly and indication will be lost.
Are there any established methods for enabling an ordinary CT to accurately measure, say, 0 to 90Hz? I can...
