I knew this last week, but I have had people telling me other things, and I need a voice of reason to get me back on the right answer.
I proposed a high impedance differential for protection of a series reactor.
I have since had people telling me that I need a low impedance differential to...
In my car the auxiliary power plugs (12V) work when I plug in a camera, or a GPS, but when I plug in with a splitter (I have tried two so far), both, the plug fails. I have found the same thing when I plug in a mini-fridge. I found this on both plugs (front and rear).
Is there some sore of...
What besides a real frequency event would make a frequency relay operate. No it did not fail, as the secondary relay also operated.
It was a SEL-300G that operated on frequency (at least that was the target).
When does CT saturation become too much?
Yes CT saturation is a problem when it impedes a relays ability to determines when it needs to operate. But what exactly is that point?
I have heard numbers of 10 to 30% for electromechinical relays. but what is it for microprocessor relays?
Several of us are having a debate about what is a communications system.
I contend that an 8 foot serial cable between two relays is not a communications system make. But others disagree.
To me a communications system connects relays between two substations, but would not include serial cables...
I've been asked to develop a one month training class for a new rotational engineer.
The problem is what to include.
One thought is one month of Symmetrical components.
But more realistic might be one month of print reading.
Any other thoughts?
Does anyone know of any studies on the percentage of different fault impedances on transmission systems?
We should all know that phase to ground faults are the most common, but what percentage are high impedance and what percentage are low impedance?
Common thinking is most faults on...
There is a news article about drones will be able to pearch on powerlines to recharge there batteries.
Are we utility engineers going to allow these energy thieves?
Does anyone have a copy of the paper "Memorandum on Thermal Current Characteristics of Current Transformers Used with Power Circuit Breakers and Power Transformers", written about 1969 by Westinghouse (the company, not the man)?
We have this referenced in several old papers, but have not been...
I have a coworker who is looking for a substation controls course/training/class to attend, and unfortunitly I can't think of any good courses on this subject. Does anyone know of any?
I have an idea for a product I want, and maybe other want but don't know it, but I am not very interested in making any money from it.
Yea I could make it, but the things I make just don't look as nice as the ones in the store.
Has anyone looked into the possibility of DC arc-flash in substation control systems? Specifically I am looking at the DC panel, and let through energy available if we remove the main DC breaker instaneious trip.
Has anyone else come across newer circuit breakers with microprocessor controlers? The problem I am running into is the trip circuit the manufacturer is expecting me to use is different than the IEEE PRSC paper on trip circuit design. The problem is the trip current is less than 20 mA, and the...
Has anyone sucessfully been able to apply a trip circuit monitor on a circuit with a lighted nameplate lockout?
The problem dosen't seem to be in the reset state of the lockout, but in the tripped state there is an interaction between the lighted nameplate and the trip circuit monitor.
The...
With the recent headline of scientests being prosecuted for failing to predice earth quacks, can engineers be far behind?
Can engineers be held accountable for not predicting other natural events?
How would anyone answer this question from NERC? "Were there alarms in place to notify of a relay misoperation?"
I would be laughing if they weren't serious.
Are there any manufacturers who's relays provide misoperation alarms?