A power outage (also called a power cut, a power out, a power blackout, a power failure, a power loss, or a blackout) is the loss of the electrical power network supply to an end user.There are many causes of power failures in an electricity network. Examples of these causes include faults at power stations, damage to electric transmission lines, substations or other parts of the distribution system, a short circuit, cascading failure, fuse or circuit breaker operation.
Power failures are particularly critical at sites where the environment and public safety are at risk. Institutions such as hospitals, sewage treatment plants, and mines will usually have backup power sources such as standby generators, which will automatically start up when electrical power is lost. Other critical systems, such as telecommunication, are also required to have emergency power. The battery room of a telephone exchange usually has arrays of lead–acid batteries for backup and also a socket for connecting a generator during extended periods of outage.
I've been told an effective induction stovetop needs to deliver about 1000W of power. I have magnet wire that can tolerate at most about 0.2A of current, and was planning on using a 60Hz wall outlet as my source (obviously I'll need to bring down the outlet current quite a bit).
So the energy...
Summary: Suggestion on experimental research related to reactor for master's degree dissertation.
Summary: Suggestion on experimental research related to reactor for master's degree dissertation.
I have just started my master's degree course in Nuclear Power Engineering and decided to...
Summary: Am seeking help understanding why when I take my battery (50V max 44 nominal; 15aH capacity; 12s5p) and attempt to step down the voltage that sometimes it works and sometimes not...
Hi all,
New to forum. Chemical engineer seeks help from electrical engineers... Thanks for reading...
I'm thinking of implementing a metal disk-like probe in an Argon plasma which is powered by RF. Therefore I need to know a metal that's least reactive with the plasma. Does molybdenum meets this requirement?
So I know the formula " W_turbine = m_flow rate * (H_in - H_out) " BUT is there any formula that utilizes the turbine volumetric flow rate (m^3/sec) at the outlet? The following data is available, I just need the formula...
P_in= 2.36 Mpa
P_out= 0.95 MPa
m_flow rate= 0.02 kg/sec
eff_turbine= 70...
hi sir
i have 1100 watt motor and i want to rotat the fly wheel from rest to 1450 rpm.i want to know how big should be the flywheel to rotate at the motor 1100 watt and to get extra energy 700 joule or more than if possiable
best regard
thnx
I have an inductive load (120 volts AC at 0.5 amps AC at 60 Hz, 0.9 power factor before correction) that is a connected to the grid. I have been trying to increase the power factor above 0.95, but no matter how much I tune the power factor correction capacitors I cannot increase the power factor...
A fully electric mining truck has been built that does not burn fuel. It has a 600 kilowatt-hour battery pack, and they need to discharge about 200 KwH of that every night to keep from overcharging it. The secret: It's loaded at the top of the hill, and unloaded at the bottom. The regenerated...
Summary: Hi there
On a 12VDC transformer we use at school. Is the positive terminal +6V above ground potential and the negative terminal -6V below ground potential?
Thank You
Hi there
On a 12VDC transformer we use at school. Is the positive terminal +6V above ground potential and the negative...
Hi everyone! Awesome forum!
I'm doubting myself on a problem about inverse square law.
I'll change the actual values from my homework problem as I want to check that I have the right idea rather than the specific numeric answer.
If I am using an inverse 2.5 power law and know the power at 100m...
I have been trying to calculate what retinal irradiance value I get with a 1 blue LED system.
Since the manufacturer didn´t give the spectral distribution information, I will approximate LED as a monochromatic one (using the 460 nm peak).
From the datasheet, the LED intensity range goes from 6...
Hi, So I have a uni project and were required to design a jockey wheel and corresponding power screw. We're given a maximum load and have to do the relevant calculations, moment of torque, efficiency etc. My question is I don't understand how to take the given maximum load and find the relevant...
So I've basically built a robot that has a lot of servo motors. 14 of them can draw up to 3 amps each(max)(usually 1 amp average) at 4.8 to 7 volts.
What's my best option to power it? The power source doesn't need to be connected to the robot, so weight shouldn't be an issue.
My best guess is...
Exelon the current owner of Three Mile Island Power Plant will shut it down in about two weeks. This is 15 year short of its current license expiration date. The reason supposedly is the cost of operation since methane is currently so cheap. Exelon tried to persuade the
Pennsylvania...
Hello, as part of the study of fields with central forces, I came across with fields called power law, defined by F = - K/r ^ n u
(u is radial vector passing through the origin O)
I would like to dismiss case n = 2, which refers to the Newtonian fields whose study was exhaustively conducted in...
Hydroelectric power, effected usually by damming a river, is ordinary considered an example of energy produced by gravitational potential.
However, from an ultimate perspective, hydro power is actually an example of solar power.
Water must drop to a lower gravitational potential to extract...
A coal fired steam plant takes in feed water at a temperature of 70°C and produces 15 tonnes of steam per hour at a pressure of 60 bar and temperature 400°C.
The fuel consumption rate is 1.5 tonnes per hour and the calorific value of the fuel is 40MJkgˉ¹.
Determine the power rating of the boiler...
I have a home appliance that should be plugged into one single wall socket because it's energy consuming, and shouldn't share with other appliances by common sense. However, due to some practical problems, I can't plug it directly into the wall socket. If I use a power extension board (i.e...
I have a socket on the wall , because of the size of the adapter, the switch on the socket is always stayed between "ON" and "OFF" while it serves and works. From the electrical point of view, is it a complete circuit inside?
is there any partial complete circuit which may be a problem?
If $y=(x^3-cos x)^5$, then $y'=$(A) $\quad 5(x^3-\cos x)^4$(B) $\quad 5(3x^2+\sin x)^4$(C) $\quad 5(3x^2+\sin x)^4$(D) $\quad 5(x^3+\sin x)^4(6x+\cos x)$(E) $\quad 5(x^3+\cos x)^4(3x+\sin x)$
ok I am sure this could be worded better. but I think many students take these tests and are not used...
Hello all,
I have designed an intake manifold for boxer-6 naturally aspirated petrol engine with 1:1 bore to stroke ratio and has a bore dia of 117.89mm and a volume of 7.8l as part of my master's project. The engine was to produce 450 bhp @ 6500 rpm and I did set a rev limit @7500 rpm. The...
I figure I could connect a high voltage source with a high impedance, and verify that it clamps that voltage. The easy way would require very careful consideration to keep it safe - that would be to use a 220V outlet connected through a 220K Ohm Resistor on each leg.
Apply the current limited...
Summary: If SCRAM completely removed all moderator from the reactor, would decay heat still be an issue?
My understanding of how decay heat occurs after shutdown in large scale Nuclear Power Reactors. Is that Beta Decay causes residual Neutron activity at a small fraction of the operating...
I was trying to calculate the EMFs from power lines, just to see how they correspond to transmission line right of ways, and got a little stuck calculating the electrostatic E-field (-∇V) from power lines. I know it is dependent on the charge distribution on the power line, which is in turn...
Summary: How do you determine the armature current during the braking time?
For a simple permanent magnet DC motor with a known resistance and inductance in series with the armature, I would like to know how to determine the armature current if there was an electronic motor drive controlling...
Intuitively I fell like AC would lose more power long a long power line than DC. I will use a model to explain my perspective.
Let me model a wire as a long straight, non-frictionless tube, about the diameter of a marble, filled with a row of marbles that are each connected to the one next to...
Hello there! So confused here, I tried to do some calculations with my power generation experimention.
In terms of energy input, the energy output is lower.
But in terms of power input, the power output is way larger.
Thanks in advance! Cheers!
My question is: is the resolving power of an array of radio telescopes a quantum or a classical effect? The increase in resolving power of a single telescope, as aperture size increases, is easy to explain in terms of Heisenberg's uncertainty principle. But when we go an array of telescopes are...
(Just as clarification on what I am doing, I am attempting to use MATLAB to create PSD plots of time series from pressure and accelerometer sensors. Wave gauge sensors might still be helpful for me. I did not discuss accelerometer sensors in the post but maybe I could figure it out if I get the...
Hello all PF members!
I was wondering about the power dissipated by resistor at high frequency which is:
##P=Re\left \{ U\cdot I^{*} \right \}=Re\left \{ \frac{\left |V^{+} \right |^{^{2}}}{2\left |Z_{c} \right |}\cdot (1-\left |\Gamma \right |^{2} )\right \}##, (1)
where:
##Z_{c}## -...
This is a hypothetical question, but..
How much computing power would all the computers in the world combined have?
Would you have a at least one YottaFLOP?
Hope you may help me to understand how detrimental to compressor motor would be if it operated at voltages exceeding the manufacturer's specified 400V by 12%? so 448V.
I have vendor engineers saying since it exceeds 10% they cannot safely run the plant and of course the voltage monitoring relay...
In theory or at least in my head, it seems simple enough to me. A simple water pump, such as a pool pump pushes water through a pipe into a water turbine and recycles the water directly back to the pump. With some of the hydrogenerators I've seen out there, they produce far more power than the...
Surely the real efficiency of Fusion power is the percentage of neutrons that can be caught to extract kinetic energy from. I am assuming it is the neutron that is carrying the nuclear energy that can be recovered from the fusion reaction.
Now I'm pretty sure neutrons cannot be focused, so the...
I was wondering, I have an engine that should keep a spring compressed. How can I calculate the power necessary for this?
The work is Force x Distance, as there is no distance, there is no work, so no power... But obviously to keep the spring compressed the engine will have to produce a...
Hi. This is my first post. Thanks to all who give it a look.
I am working on an application that has very stringent power output requirements. There is a rechargeable battery that I am trying to manage through a bi-directional boost/buck converter as is typical of many modern-day electric...
I am trying some projects that involve building some very simple electrostatic motors. I attached below figures of the kind of electrostatic motors I am trying to make. What I can't figure out is what kind of high-voltage power supply I should use, presumably 1000 to 10,000 volts is what these...
This is for safely powering up devices being tested/repaired. Supply is 240V rms single phase, protected by 32A MCB and 30 mA RCD/GFCI, then fused at 13A.
There doesn’t seem to be a consensus online, and my EE and repair books just say I need both, without specifying order.
I think the...
To cover transformer loss at no load and maintain pf, we are needing 6kvar at day time and 9 kvar at evening.
Is there any time based switch available, such that it can switch ON 3 kvar at evening, say 8:00pm and turn off automatically at 8:00AM morning
Hi,
I was reading a newspaper article on the energy efficiency of commonly used air conditioners in homes. Then a doubt arose when the article informed me that there are air conditioners that have an energy efficiency of 10 BTU/watt. That means a classic 10,000 BTU/h air conditioning machine...
Good afternoon everyone, I need help with a certain calculation. How much power is needed to pull a 250lb load up a 45 degree incline at 5 mph. I am working on a project at school and would like to know what kind of motor we can use. Thank you very much!
Hi there,
I have a query about electric power in AC systems. I am Chilean, and over here the power supply is 220 V (rms) at 50 Hz. Some countries use voltages in the range 200-230, but others use 110 V or so, at frequencies of 60 Hz. There is no uniqueness, but all work. My question is...
Relevant equation:
Since the potential difference V is independent of time and current I is steady, both the electric field and magnetic field are independent of time. Hence, the first term of R.H.S. of (8.9) is 0.
If V >0, then ## V_{in} - V_{out} ## = V,
## \Rightarrow...