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How Negative phase sequence relay work
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How did scientific management change factory work?
Factories changed peoples lives for the better in the respect that jobs were created, keeping the community employed. However, the negative effects were that factories usually created pollution, and the repetitive work employees performed had adverse psychological effects.
Identify the products of the SDLC phases?
For developing systems/software that involves 10 Phases: 1. Initiation 2. System Concept Development 3. Planning 4. Requirements Analysis 5. Design 6. Development 7. Integration and Testing 8. Implementation 9. Operations and Maintenance 10. Disposition. The Phases Initiation - Initiation is where there is an identified need for a new system. For instance, a retailer of fine crystal glass is in need of a new system to handle inventory. They've decided that the old System of putting the inventory into a simple spreadsheet will no longer work. They want a system where they can track inventory, inventory cost, facilities cost, personnel, a customer database, can track trends in buying, identify inventory that is not moving well and price it to move, etc. In other words, they want to be able to know everything with a few clicks of the keyboard. A Project Management is placed in charge and he/she will develop a Concept Proposal - which is a document identifying the problem and why the new system needs to be pursued. The document is presented to upper management who approves it and the project moves on to the next phase. System Concept Development - This is where the first real look at what will be necessary takes place. Several reports can be created here. - Feasibility Study (will it work?) - Cost/Benefit Analysis (is the cost really worth it?) - System Boundary (how far should the project go?) - Risk Management (what will happen if we don't do it?) These reports are then presented, again, to the powers that be and a decision is made whether or not to go ahead. They approve the funding. If they give their approval it's on to the next phase. Planning Phase - Who is doing what, when, and how? What personnel are needed? Use existing personnel or hire consultants? New Hardware? Develop own software or buy it off the shelf? What are the Deliverables - such as completed software programming and documentation, user manual, training, testing plans, etc? A Planning document is submitted for approval. Requirements Analysis - Documentation of requirements. What interfaces are required (will it run with Windows NT and Windows XP?). What is the functionality required - should it be run with the mouse or keyboard commands? What is the level of proficiency required by the user? Will a new room be needed for the servers or equipment? Requirements documentation is approved, then it's on to the Design phase. Design Phase - Take those Requirements and develop detailed, workable specifications. This is where everything is put together and the actual design of the system is done. This is also where documentation such as the Maintenance Manual, Operations Manual, and Training Manual begin. This is also where some of the flaws in the original planning may appear and require some adjustment. Again, there is documentation and approval. Development Phase - The system is built. The software, hardware, and testing occur during the Development Stage. This is also the phase where the bugs are worked out of the system. A contingency plan is also developed at this point. A contingency plan is an emergency management document. If the power goes out - what happens to the system? What is the back up? How fast can it be brought back up to speed? Again, documentation and approval (get used to this). Integration and Testing Phase - This is the formal integration and testing of the system. Testing has been done on the development phase, but in the Integration and Testing Phase it is a formal, documented testing procedure, not only to assure that the system performs as designed, but testing the roll-out of the system. If there is already another system in place with data, how fast can that data be migrated into the new system and useable to the company? Usually, the system is rolled-out over a weekend so that if anything goes wrong, the old system is still active and available. Integration and Testing is vital to the decision to go "live" with the new system. If it fails testing, it cannot be trusted to work. Approval of testing and test results is necessary before the project moves into implementation. Implementation Phase - Everything is ready and it's time to go live. Training takes place, everyone who will use the system must be fully informed of the day it goes live, previous data is migrated, and the system is ready for use. After it goes live, the system is reviewed post-implementation to see how well it worked and how well did the project go. It's often known as a debriefing or lessons learned meeting. It is also where any problems that were not crucial to the implementation can be addressed and any necessary changes to the system documented for future versions. Operations and Maintenance Phase - Hey, it's not over. Just like a car engine, maintenance and support are necessary. What happens if the system is based on Microsoft NT 4.0 and 2 years later Microsoft is no longer supporting NT 4.0? Or, a new e-mail program is put in place and it interferes with the system? Fixes are necessary and will occur. This is the day-to-day operation of the software. No one can just walk away once the software is rolled-out and say, "Whew, glad that's over." It's not over; it's just begun. Disposition Phase - This is where the system has become obsolete. Perhaps a whole new system is coming in, or this system cannot keep up. Many programs and systems became obsolete with the Y2K problem or with upgrades of operating systems. Whatever the reason, putting the system to bed involves more than just shutting off the server. Often, the system may be kept going due to regulatory issues or because there are still projects using it. Even if the system will be shut down due to the development of a better system, disposition needs planning. A disposition plan, archiving of system documentation, archiving of data, even a plan for getting rid of the old equipment may be a part of the Disposition Phase. This is a short description of SDLC and its phases. The important idea to take away from SDLC is that it involves planning, approval, testing, and documentation to assure that the system can, and will work as required.
What are the importance of engineering management?
the engineering manager overlooks other engineers work if they work for them.
How pre-fabrication method can speed up steel work operation?
Pre-fabrication methods can speed up steel work operations by allowing small portions of the work to be completed off-site, freeing up machines for larger portions of the work.
How can arc blow be controlled?
It can be controlled by connecting the work lead to tha end of tha weld joint and than welding away from the work leadThe ARC blow can be controlled by connecting the work lead to the end of the weld join. Then you will have to weld away from the work lead.
What is the work of phase failure?
A phase failure relay monitors the incoming three phase service lines. If the lines become reversed or loss of one phase causing single phasing, the relay's internal contacts change status. In control panels the control voltage usually is connected through the phase failure relay's auxiliary contacts. If any line anomalies occur the control voltage is cut off and the panel becomes inoperable. Once the line fault is corrected the fault relay senses that everything is alright and then allows the control voltage to power the control panel again.
How does apfc relay work?
how the apfc relay work
How does a triangle sequence work?
A triangle that is in a sequence
What is the advantage and disadvantage of open delta bank transformer?
A disadvantage with Open Delta is there are no phase-ground voltage measurements, which is only a disadvantage if directional relaying or distance relaying is needed. Some directional and voltage based ground fault detection relays don't work without the phase to ground input. Since most industrial systems MV are high resistance grounded and ground fault protection is provided by overcurrent, there isn't a need for the phase-ground measurements.Why will the directional or distance relaying not work in this case?5. Most directional and distance relays need a voltage to ground reference to compare with the phase current nfr groudn faults. Some can use a zero sequence polarising current from CT's on the neutral of the transformer, but most need phase-neutral voltages for accurate calculation of fault direction and distance.The relay needs to see a zero sequence voltage to compare to the zero sequence current to find out which direction the current is flowing.Precise Phase-ground voltages are needed for this type of calculation, whether it is done digitally or with analog circuits or windings, coils and phae shifting circuits.The voltages provided by the Open Delta do not have enough zero sequence component.
Why does Fibonacci sequence work?
Work for what?
What ia a farey sequence?
how to work out the farey sequence for f9
Can work done by a force be negative?
Yes. If force is negative, then work will be negative.
What is a project phase?
A Project Phase is a timeline in the Project lifecycle where a related set of activites are performed. Once those activites are completed, work begins in the next phase. For ex: After the Project Initiation Phase is completed, work begins in the Project Planning phase. Once Planning phase is complete, work begins in the Project Execution phase and so on...
What happens when a phase gets short and also when it get opened in a delta and star connection?
In star connection when two phase is short,it work as single phase system. In delta when one phase is open ,it work as a single phase.
If fuel pump relay is bad will fuel pump still work?
If the relay is bad, then the fuel pump will not work.
When work is positive and when is negative?
when work is positive and when playing is negative
Using ccor work on contaminated material when must you work in mopp 4?
during the initial phase
