Fault Definition and 115 Threads

Here is the valve in question, an Enolgas R2835P00: The default state is shut, as shown by the red indicator in the picture, oriented crossways. When activated, either by the frost ‘stat, or the user, the valve opens 90deg, and at the end of travel, switches on a pump: Rating plate: The...

I use Python scripts to run mcnp.mpi like And I encountered this bug report The scipts has run normally for a few hours. I extracted the inp file and it can be run normally. I searched on Internet and found it seems to be the problem related to memory, but i checked the log, there's still...

Why is it said that full-bridges are fault tolerant compared to half-bridge?

If I have two parallel bars serving as a DC bus with a capacitor across the output and there is a short fault event, I know the peak current is limited by V/X. The instantaneous current would be a function of the time RLC time constant. How do I relate this to the force on the conductors due to...

I have bolded the text. I have two problems: Page fault occurs if the page is not in memory but the above text says that (a)the page fault occurs at the time of modifying or writing the page? I can’t understand that. (b) Also I can't understand the text “, allowing the operating system to set...

Guys this circuit and shematic is of UV lamp controller.. It burns sometime as shown in figure can someone tell the reason?

https://www.nationalgeographic.com/science/2019/12/first-active-fault-system-found-mars2/ One insight on this is seismometers on Mars can provide data driven inferences about Mars deep crust structure with reliably located fault zones. Based on paper presented at AGU FallMeeting 2019 ...

I’ve just bought this useful looking 100 MHz scope in the hope of repairing it. When I switch to digital mode, the trace disappears off-screen on all four channels. 1 and 3 are up high, 2 and 4 down low. Sometimes the top or bottom of the trace is visible, and it flickers up and down the...

Symptoms: Random shutdown of entire fridge/freezer, blank display. Restarts after a variable interval. Power cycling doesn’t seem to help. Forums etc., suggest ‘replacing motherboard’ (on top) but this is often expensive and may not be available. I managed to catch it in shutdown, and found...

The SMPS in our PC went out a few months back. I confirmed that the device was not working by shorting the green and anyone black wires on the 24-pin motherboard connector. This was doubly confirmed by the mechanic who came to install a new SMPS. I was checking online for procedures to detect...

Summary: Should both envelope detection and windowing+overlapping be used before FFT? Summary: Should both envelope detection and windowing+overlapping be used before FFT? Hi everyone! I'm somewhat a newbie to signal analysis, but I've also noticed that there seem to be many different...

Hi. After some study, I came across symmetrical components. I found the attached schematic below on the internet, and will use it to explain my question. Question: Imagine that a single-line to Earth fault occur in one of the phases, i.e. resulting in an unbalanced system (we assume it was...

Homework Statement FIGURE 2 shows an improved arrangement for separating water from the hydrocarbon liquid for the process in question 2. Two simple level control loops, LC, have been added to regulate flow control valves on a pumped system. Extra protection is also provided in the form of high...

We have been testing a Cummins VTA-1710-G2 Diesel Generator 1800 RPM 480 Vac 671 kW with an Avtron K580 load bank that is hooked up to our three 480 Vac output cables and one cable to our facility ground. The generator output breaker keeps tripping when the load is around 350 kW. The test...

Homework Statement For the system shown in FIGURE 2, using a 10 MVA base, calculate the fault MVA levels through each unit and the base "voltage" MVA across each unit for a fault at F. Draw the impedance diagrams showing the fault levels and the base "voltage" MVA across each unit for: (a) bus...

I have a Dettol automatic soap dispenser (see fig. 1) which uses a little propellor-type pump to let out a small amount of soap when you put your hand in front of the passive IR sensor. It's been working fine until just before, when I turned the lights off in the kitchen (night time, so...

How come I saw a video of a magnitude 6.9 earthquake on the island of Hawaii on the evening news just now, and the grocery store products were not even falling off the shelves (and no deaths or injuries), versus the same magnitude earthquake prediction here on top of the Hayward Fault (east of...

Homework Statement Write a C program to run on ocelot to find the total count of words and optionally the longest and or shortest words in a string input by the user or coming from a file. If there is no filename the user would be prompted to enter the string. You must use getopt to parse the...

Hello, I'm currently constructing an electric bicycle using a 500w 24v motor, 2X24v 7ah batteries (maybe 4 later on). I bought a 24v 30a dimmer switch to use as a "throttle". During the intitial test (on a table, not on the bike!) It worked absolutely fine for 2 minutes, but then began to smoke...

Homework Statement Homework Equations If load is inductive current lags voltage. If load is capacitive voltage lags current The Attempt at a Solution Current lags voltage since wire is inductive. So IF1 lags VF1 and IF2 lags VF2 But book says answer is C Why should VF1 lag IF1? This will...

This circa 1990 scope has started to display a retrace line when handling a sine wave. It’s only visible on the left 1/4 of the screen. The fault doesn’t appear when the square wave cal is used. Looking at the block diagram, and from initial thoughts, I’m guessing the blanking signal must be...

Hi, I was trying to learn fault analysis in three phase system from conceptual point of view. I need your help to clarify few seemingly contradictory points in the following video: 1: At 32: 42, phase to ground fault in introduced. It is said that line voltage Vbc is not affected as is also...

Some Japanese scientists want to drill from the bottom of S. African mines into faults of recent earthquakes. Science news story here.

How would you justify the above question? Please elaborate in detail with diagrams (if applicable). It will be really helpful. Thank you.

Hi all. I'm planning on moving out of my parents home a few years from now (never too early to plan), and I want to eventually settle in a place that is as safe as possible and future-proof from natural disasters (and climate change) as much as possible. Upstate New York seems like a good place...

Hi All, would someone (hopefully a professional), who has used Fault Tree Analysis read my essay and give me some pointers for improvement? I'd really appreciate if someone could help, especially since this is the only essay I've written in recent years.

Following on from my last post about stream offsets along active faults. This post is a little more about the Alpine Fault in particular. This is more about a place of interest, rather than about the science of tectonics Just off State Highway 7 ( the Lewis Pass Rd) that connects the east and...

I was zooming around the NE region of the South Island of New Zealand in Google Earth today and discovered a classic example of offset stream channels across a major fault, the Awatere Fault. The Awatere Fault which is one of the major faults that the Alpine fault splinters into in the upper...

Hi, I am studying transmission lines faults. There was a line that said In case of delta star transformer in transmission line, an Earth fault on star (grounded) side is seen as a line to line fault on delta side. There was no explanation. I tried to google solutions but couldn't find any...

I'm trying to resolve an issue I'm experiencing with some overhead power distribution lines, was wondering if anyone can help me out. Here is the scenario: three phase, 4 wire, wye connected 13.4kV power distribution system. 556.5kcmil bare ACRS wire is mounted on a crossarm 24" apart over a...

Homework Statement Reduction from top network to bottom network in the screen shot. I can not find the steps that have been taken to do this. Fault impedance = Zfa = Zfb = Zfc = j0.5 Homework EquationsThe Attempt at a Solution in hand written screenshot, sorry for the mess, just to show it...

Homework Statement [/B] All voltages and impedances are in per unit values. After all the source transformations, why is the voltage source still 1 ? Homework EquationsThe Attempt at a Solution [/B]

I used to have a bunch of these on - ahem VHS,,, This was one that I think shows - all bets are off on trying to predict ground fault current... Even the firemen, keeping their distance (not enough IMO), are almost fooled as the arc stops around 1:42.. nope.

5.2-Magnitude Earthquake Rattles Southern California, Felt in Los Angeles, San Diego https://gma.yahoo.com/5-2-magnitude-earthquake-rattles-southern-california-felt-112449426--abc-news-topstories.html M5.2 - 20km NNW of Borrego Springs, CA...

Dear friends,May I know how to calculate the Earth fault relay/ Earth leakage relay? When we going to use them? Thank you.Regards, Jason

Hi, I have a project for a class in numerics, where I have to write a program with FORTRAN 90 that calculates the determinant of a matrix using Laplace. The program itself works now, but I have added a function that finds the row/column with most zeroes and reorganizes the matrix, so that they...

Hello, I'm a very slow learner! I try to understand every piece of the information that is given. And recently I was solving some problems involving symmetrical components and I couldn't figure this one out: -The neutral is solidly grounded. -Phase B and C are open. -You're shorting Phase A...

I am stuck on some non-coherent fault tree analysis. I have a non-coherent fault tree for which the TOP event breaks down to TOP = AD' + DA' + A'E. These are (I think) some of the prime implicants of the fault tree. There is also another prime implicant ED'. I've been trying to work through it...

Hi, everybody today I have got a problem in my Allen Breadly PLC which is after getting emergency HMI shows emergency button pressed and after pull the emergency it can't reset and it was noticed that Plc fault indicator shows blinking. I have checked all corresponding issue & make all things...

Homework Statement Given the relationships: Xpu = MVAbase / MVAfault Xpu = ( MVAbase / MVArated ) * ( X% / 100 ) MVAfault = sqrt(3) * V * Ifault Xohms = [ V / sqrt(3) ] * Ifault Homework Equations Show that: Xpu = [ MVAbase / V^2 ] * Xohms The Attempt at a Solution No matter how I...

the other interpreter I'm using? I'm practicing my coding chops for an upcoming interview (I don't really have to use any hardcore programming chops I work as a web dev) and have been writing small C++ programs on online compilers/interpreters because I hate having to make entire new projects...

I work on a ship, and we have a 440V ungrounded distribution system. We have load centers that have transformers bumping that 440V down to 120V for recepticles and other services. This standard ship setup always has ground fault detection on the 440V side (at the switchboards) and at each...

Hello, I am wondering where a good article may be discussing the theory behind DC arc fault detection for PV systems. Seems most articles are based on detection for AC circuits. Trying to have a better understanding for troubleshooting purposes.

Hi, apologies if this is very simple but I am still learning the basics of power system analysis and would like it if someone would be able to clarify what I have been told regarding system fault levels and subsequent system reactance values (X) from this. Basically, I have been told that...

Homework Statement Consider the following incorrect theorem: ∃x∈ℝ ∀y∈ℝ (xy^2 = y-x) [Translation (not part of the original problem statement): There is at least an x∈ℝ such that, for every y∈ℝ, (xy^2 = y-x).] What's wrong with the following proof? Let x = y(y^2+1), then...

Hey! :o I have to write a function for the destruction of the planetary system "solid". With the destruction of the planetary system, the asteroids where the gap between this one and the object, is at least "gap" will also be destructed. (so, they have to be deleted) The asteroids for which...

Any idea how can we decide on the fault current time 1, 3 or 5 sec. for grounding cable sizing? Also, what is the related temperature to the selected timing?

Hi, When calculating a line-line fault, I understand that the Positive and Negative Phase Sequence networks are placed in parallel with each other as shown in the first attached image, and that the zero phase sequence is excluded. Although this is connected in parallel, does it not produce a...

Dear everyone, Can anyone explain how variation of Stacking Fault Energy(SFE) for different Face Centered Cubic(FCC) materials affect the stain hardening rate? For example SFE of aluminium is 250 mJ/m^2 and that of stainless steel is 9 mJ/m^2. Can you please explain which material has higher...

Hello again, I've got another question that involves symmetrical components, this time I've attempted it. The Question follows: 1. In a 3 phase circuit with resistance earthed and neutral and Earth fault in phase “A” which produces a fault current of 800 amps. Load currents may be taken as...