I am a project engineer for a substation. We are installing an emergency generator at the site. The generator is fueled by liquied propane. I would like to know if anyone can point me in the right direction for the proper sizing of the fuel line. The generator vendor does not do this and I would...
MVA is the aparant power, MW is the real power and, MVAR is reactive power. If you remember your Circuit II course MVA is the Square Root of MW^2+MVAR^2. Just like a right triangle. It is actually called the power triangle. You adjust the MW of a plant based on the load on the grid. Generation =...
I don't have any experience with a Ladle furnace. However I do have about 38 AMVAC breakers by ABB in service with 39 more going in service in March of 2006. After some initial problems with interference on the control circuit board of the breaker causeing errant trips they have worked well. We...
I have actually used about 80 of ABB's AMVAC MV VCB in power plant applications. I have only had them in service for a year and besides some minor RFI noise issues they have worked well. They do not rely on the DC voltage to stay in position however they do rely heavily on it to change state...
From what I know of shell form transformers it is suicide to run them without the oil pumps running. The oil does not circulate well using natural convection. We are very carefull never to run our shell forms without at least one pump running. I would say this is true of this unit also since its...
Are you talking about arc resistant switchgear? I just purchased some arc resistant 7.2 kv gear. For that application the low voltage control equipment has to be in a separate compartment than the breaker and there can be no instruments mounted on the breaker door. As for standard switchgear I...
I am in the process of puchasing a transformer for a project I am doing. One of our first steps in evaluating the bids is looking at the mass of the units. We found them to be about the same with a caveat. One manufacturer had much more core and coil weight and less oil than the others. Around...
This is all based on memory so I would still verify it with technical support at SKM. They are usually very helpful.
For the 750
INST OC_PU is the pickup value for the instantaneous 50 element in a multiple of full load amps.
O/L pickup is the pickup level in multiples of full load amps for...
Before looking at a transformer I would also look at the load. Is it a motor? If so the rated nameplate voltage may take into account the voltage drop accross the feeder cables. For instance here our motors are typically rated for 460V nameplate and are connected to a 480 V system. I would make...
Why don't you just use a fuse on the primary side of the transformer. 800 Watts at 220 V works out to be about 3.5 amps. Maybe the circuit design and building is a achedemic exercise for you which is fine. But when you start looking at the time and cost involved in the circuit I think the fuses...
What he means is when you close the pistol switch to trip the breaker there will be 3A of current flowing through the switch. But typically there are 52a switches wired in series with the trip coil to interupt the tripping circuit. This ensures that if the breaker trips and the contact...
Thanks everyone for your help. I should have said this earlier but the sytem voltage is 4160V with a restively grounded Y transformer feeding it. I have decided on a 5kv/8kv EPR with CPE jacket cable. This gives me more insulation than needed in the event of an overvoltage due to a ground fault...
Does anyone know what the differences are? I am buying about 20k feet of 5kV power cable and found that the 2 main choices are EPR insulation with a PVC jacket or XLPE insulation with a PVC jacket. What are the tradeoffs of the two?
On a side note should I get shielded cable for this voltage...
As long as one tap of a muliratio CT is used the other taps can be left open. It is transformer theory that all the flux will go to the used terminals and the unused terminals will have no voltage on them.
