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Thair... how large is the load vs the load? Regards, Phil Corso [email protected]

Vahid... send me your e-mail address! Regards, Phil Corso [email protected]

Tom... would you like a copy of my paper, "Probabilistic Risk Assessment of Safety Systems!" as a starter! The List of references and Bibliography may prove helpful! Regards, Phil Corso

Moses... this might be handled with Boost-Buck transformers, depending on what you meant by "above" 240V! Regards, Phil Corso

MWO... I presume the SEL Auto-Sync system uses an Anticipatory Logic Scheme! If so, then the close-signal is initiated when the phase-angle between the incomer and the bus is a specific value. Determination of the angle requires knowledge of the closing-time of the Circuit Breaker AND...

MWO... which generator voltage is higher; incoming, or bus? Can you monitor the voltage-signals via an oscillograph or a storage-scope? Regards, Phil

MWO... slip-rate is only one parameter during synchronization. What is the voltage differential? Regards, Phil Corso

Nic... amendment to my earlier post: Failure-to-trip probability, w/o tie-breaker, is (N)x(Qf), where N represents the number of breakers that are tripped! Probability, with tie-breaker, is (N)x(Qf^2)! Regards, Phil

Praveen... your assumption is incorrect: The relationship between no-load current and no-load power is not linear. No-load power is based only on stator-winding loss at no-load, excitation-loss, friction, windage, and stray losses. For example, for a 15kW motor, the no-load loss is about...

Nic... I too meant no disrespect of your knowledge, design experience, or commissioning skills. My logic-strategy suggestion was only meant to illustrate that with the addition of the "Tie" breaker, risk of failure was reduced by several Orders-of-Magnitude, i.e., Qf^2 (Qf represents the...

Sangeetha... There is no way the DG-set can escape serious damage if the Main-Bus load is suddenly dumped on it... regardless of how fast the load-shedding scheme operates. I suggest the establishment of a Critical-Load bus! It should be connected to the DG-set via the DG-breaker, and also to...

NTT... What do you mean by "Control Methods?" Do you mean your own design? Or Electronic Systems that are commercially available? Or Mecanical-Brakes similar to those in automobiles (which are somewhat electro-hydraulic? Can you provide additional detail? Is your application related to a...

Newtothis... there are well over 250 "Braking" threads in the Control.Com Archives. At least tell us what you have already reviewed, Regards, Phil C0rso

Mike... the answer to your question is no! That is, a transformer's kVA capacity is determined by the load it has to carry. A transformer's primary-winding is designed to withstand the effects of a short-circuit on its secondary terminals. This is why transformers have a minimums...

Rock… The formula refers to Steady-State operating conditions, i.e., no changes. At 90º the system will not survive System Transients such as electrical-faults or even operational changes. For example, if there is a load change, the prime-mover will respond but because of system-inertia the...

A-B... it could depend on the type of barrier. 1) What happens to the input-voltage to the barrier? 2) As a test what happens if the transmitter is moved to another barrier? 3) How about additional info like manufacturer and type? Regards, Phil Corso

Shaheed... I will use my Gi.Fi.E.S. method (pronounced Jiffy’s) for an approximate solution. Gi. is for “Given”; Fi. for "Find"; E. for "Equation"; and S. for "Solution!" A) Given: 3-phase source of infinite power having a voltage, Vb = 400V; Short-circuit fault-current, Isc = 65,000A...

Chandru.. If your application is related to a motor drive, then contact Danfoss If your application is interfacing two power systems having differing frequencies, e.g., 60 to 25 Hz, then contact ABB! Regards, Phil Corso

Shaeed... what is the motor size? Phill Corso ([email protected])

Mr. Jamiyandorj... your questions encompass a rather large topic. But if maximum reliability is the goal, then here are a few suggestions for Grid-connection via a GSU xfmr: 1) The generator-voltage winding (call it the primary) should be Delta-connected. 2) The high-voltage winding (call...