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DonnyM... The fact is... NEC Article 240.22 prohibits installation of a fuse in series with any conductor intentionally grounded, except in one situation. Article 420.36 states (paraphrasing) where fuses are used for motor overload protection in 3-phase, 3-wire systems having one one...

Jraef2... There are two time-axis crossings per period. Regards, Phil Corso

Tahir Mubeen... the reference given was wrong. It should be: http://www.control.com/Thread/1419896241 "The Physics of Tap-Changing" Phil Corso

Tahirmubeen... see the following Control.Com thread: http://www.control.com/Thread/1442130194 "The Physics of Tap-Change" Regards, Phil Corso

StormRiderRit... Can you send me a photo? Phil Corso @ [email protected]

StormRiderRit - Magnetic-core structures are intentionally insulated from earth/ground. But, an intentional connection to earth/ground is made via a removable cable or strap. Without the connection insulation-failures would go unnoticed! Regards, Phil

Hellcat8691... By "Software" do you mean a commercially available program to calculate Momentary (1st-Cycle pk) and Interrupting Duty? The former is sometimes called "Closing-Duty" while the latter is called "Opening-Duty." Regards, Phil Corso

Bruce... Also contact "The Surplus Record" Email: www.surplusrecord.com Tel: 312-372-0977 (Ask for Al "G") Regards, Phil Corso

Sudamadhav, the three prevalent types of protection used are: 1) DC-Voltage Measurement A voltage-relay is connected between the center-tap of resistor in parallel with the rotor, and earth rotor winding and earth. Virtually any EF will produce a voltage which is detected by the relay...

Since the turbine has jets, it's a Pelton wheel. Thus power is relatd to H, Q, Density, gravity, and jet-stream velocity. Regards, Phil

Send it to me at: [email protected] Phil

Eddie.... a Single-Line-Diagram (SLD) or hand-drawn sketch would be very helpful. Regards, Phil Corso

Alejandrom... As a subscriber, I found out that Power-Mag archives only go back to 2005. I have a copy of John Yoon's article, "Ten Pitfalls of VFD Design!" If you want a copy contact me at: [email protected] Regards, Phil Corso

Cooper_Doly... perhaps my JSSS paper "Probability Risk Analysis of Equipment Safety Systems" can help. Contact me at [email protected]

Irhazidi... Did you compare new alignment measurements to original? Regards, Phil Corso

Ahdash... to start: o Age o Size (to ascertain adequacy of pig-tail wire) o # Total Starts and condition (on or off load) o Noises during start. o Time to accelerate. o DOL or reduced voltage starting. o kVA/Hp ratio. o Operational history. o Protection device operation. o...

Wikash... A1) At the time of the fault, no generator power can be transmitted to the load. In addition the generator's terminal-voltage sharply decreases. Subsequently, within a fraction of a second, generator (and prime-mover) start to accelerate because of imbalance between mechanical-input...

Stormrider... using a smaller motor to accelerate a larger motor is called the "Pony Motor" method! Caveats: 1) Sometimes an error is made when the smaller motor's unable to provide the necessary breakaway-torque. 2) Sometimes,especially if the driven-machine is a pump, fan, or...

CSA, you are correct again! But the proper answer is in my JSSS paper. In case your curiosity is piqued JSSS means "Journal of System Safety Society." Phil

Rarely, but once in awhile I agree with CSA! In this case his suggestion to provide a pre-trip, or an off-normal alarm is right-on! BTW, 2oo4 logic is std on the nuke-side of Nuke plants! My paper discusses the Pro's and Con's on its implementation. Phil