If you were payed to do so, or at least asked about- how would 1,500 foot tall rigid steal frame supper tall design compare in regards to steel usage? Roughly speaking, what is the optimal column spacing from a strength, stiffness and sway perspective?
A major transmission tower structure appears to have collapsed into the Mississippi river blacking out all of New Orleans/Orleans Parish:
https://imgur.com/mLEWQDZ
Reports indicate this to have been a vital power path-...
What year did operate and restrain become the norm in differential relaying in power plants and substations? Or when was it realized that systems needed this? I ask out of curiosity looking at protective relaying books from the 1900s where bus, line, generator and transformer differential CTs...
What is typically the best way to go about mitigating post contingency sag in overhead lines from a relaying perspective? Would operator intervention alone be sufficient or is some type of scheme also required as a back-up and what the preferred way to go about? Boolean logic with a timer, 51 or...
Transformer exploded in a vault sending flame up from sidewalk vents injuring a man who just happened to pass by.
Can anyone guess as to what went wrong or what would the technical cause be behind such a dramatic failure mode...
Queens New York showing a vent explode spewing fire. The man survives but with burns.
Any ideas on what might have caused this?
https://www.nbcnewyork.com/news/local/shocking-video-shows-man-survive-sidewalk-explosion-in-queens/3177378/
Is it ever done, or even doable, to have the backup DC system be able to run the spring charge motors and MOABs for the blackout failure of the primary DC system?
What is typically for your utilities regarding the backup DC wiring- do you keep the all back up wiring dedicated to the back up...
Is there any benefit to ditching rotary switches in substations and letting relay push buttons and LCD mimics do the HMI?
Also, what is the typical way one goes about blocking close with rotatory switches if both primary and secondary relays happen to be disabled or unarmed?
Looks simpler...
Why do some utilities, primarily those outside North America, choose to use a independent bay control relay separate from the protection relay?
Why not just combine the bay control and protection functions into a single 421 or 411L? Seems a bit redundant to utilize a 451 just for bay control...
A down stream 13.8kv line fault caused A and B phase cutouts to blow tasked with protecting a 23kv-13.8kv auto transformer bank.
A bit of info on the scheme going from back to front: 23kv incoming line, 100K primary fuse links, 3 1254kva 13.2kv-7.9kv step down auto transformers, VT bank for the...
So a thing happened.
A while back several members were asking me why I believe in covered tree wire and spacer cable. So this happened today- a tree branch fell on a bare 23kv wire segment driving the main trunk line to lockout directly resulting in 1,404 outages including a dozen restaurants...
In 1979, did code require that a flow sensor on a sprinkler standpipe trigger the building's alarm siren? Does code require that sprinkler flow trigger internal sirens today?
Cost aside, would it be technically possible to operate an underground transmission grid consisting of solid dielectric cables? Burying all transmission lines 500kv and below on the east coast, west coast, UK or European Union as a discussion reference.
Would shunt reactors at each substation...
An educational lesson from the 136th Protection Sub-Committee Meeting where a kite string resulted in the loss of five 400kv transmission lines, two compensation reactors, and three interconnecting auto transformers where at most only 4 elements would have cleared.
I think this is...
What advantage would be reasonable in a scheme using 4 or 5 smaller power transformers operating in parallel vs 2 larger units run normally open as typically seen in the wild?
For example four 12/16/20MVA transformers vs two 40/50/60MVA 115-23kv transformers.
Similarly five 15/20/25MVA vs two...
Question- are steal framed buildings less likely to pancake or have a total collapse? Why weren't the Champlain towers framed out of steal? Would the incident been less likely to have occurred? Why is concrete chosen over steal?
Does anyone have a table, or know how to calculate the voltage droop on the secondary output terminals of typical distribution transformers for a given over current or short circuit value above the nameplate rating?
I'm running some equations in regards to touch and step potential.
How do I determine short circuit current (L-G and L-L-L) of standby generator set, in the 125-750kw range? How long can a set handle or export this current? What happens when it goes beyond 10 seconds? Does the current differ the first few cycles vs the rest of the duration? What happens to the...
Posted on another forum, but I want to ask here. Why does this keep happening? I mean I could see this happening (and it does) in countries where things like busbar protection were/are optional, however I can't imagine it happening to a station such as this in the US...
What is the purpose of manufacturers/engineers placing disconnects smack in the middle of busbars? Seems pointless, and if anything reduces the availability of any one busbar. Anyone agree this is pointlessly stupid?
https://www.youtube.com/watch?v=k-Oonc1JCLk
