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Krish, further to my 25-Dec-09 (13:21) post... I should have said measure capacitance, when possible, of all 15kV components, such as LA's, PT's, excitation xfmr, and aux load xfmrs, using your Tan-delta test equip. Phil

Krish, analysis thus far: o Voltage Unbalance. Data derived from PT readings shows Ph-Ph VUF is less than 0.2 pct while the Ph-Grnd VUF is about 8.8 pct. Thus indicating harmonics are not an issue. And because GSU+Duct capacitance, ignoring unbalance, are considerably less than that of the...

Win... Torque (in mN) is Power (in Watts) divided by Angular Speed (Omega in Radians per Sec) Regards, Phil Corso

Krish... further to earlier e-mail: Remy Q3, sorry, I overlooked 3.5/5.8 value! Q8) Which phase is represented by "new" xfmr... R-Y, Y-B, or B-R? Q9) Is the NGT comprised of a single 3-ph distribution type xfmr, three 1-ph xfmrs, or a zig-zag transformer (NGZ)? Rated ph-ph, or rated...

Krish... there should be no ill effects at the power frequency. But, the difference could affect the ability to withstand transient phenomena caused by very high dv/dt waves initiated by lightning and switching surges. The data supplied is insufficient to provide a quantitative analysis. I...

Responding to Danesh's 11-Dec-09 query... can you provide the Model Number of the Flame-Eye Scanner? Regards, Phil Corso

Responding to Hussain's 18-Dec-09... as first step have you determined total capacitance-to-earth of 3-kV system? Regards, Phil Corso

Ask... search Control List Archives for thread # 1026226787. It may provide you with a course-of-action toward solution! Regards, Phil Corso

Usman Ghani, were you ever involved with the ECPL Fertilizer Plant in Dakari? Phil Corso?

Responding to Skyman's 10-Dec-09 (15:15) query... Quite a bit of info was made available in the Control.com Thread # 956947997, of 2002. Regards, Phil Corso

Responding to sd's 02-Dec-09 (23:18) post... repeating your observation... "I cant think of any reason that may cause the shaft is mechanically stopping the shaft from breaking away from standstill as I cant observe any abnormality from the bearing metal temperature, lube oil temperature...

Pramod... The question you asked me should be addressed to the xfmr specifier and the xfmr vendors associated with your project. However, my answer follows: The problems associated with 3-phase, 2-winding Y-Y core-type transformers is that that the zero-sequence component can't be readily...

Jeremy... if a chain is used, then there must be a sprocket. The sprocket has teeth! Are the number of teeth in one revolution proportional to distance traveled? Phil

Jeremy... Any possibility of sending a sketch or photo of your installation? Phil

Jeremy... how about another: 5) Mag pickup via a Hall-switch. Regards, Phil Corso

Jeremy... how about: 1) An optical-tach to monitor a rotating element in the drive train. 2) Then have the optical-tach output trigger a spark plug. 3) Finally use a commercially available wireless-tach, used to monitor combustion engines, to transmit to a receiver. Or 4) Use the...

RAJ and SR... I urge you to search the Control List Archives for both NGR and NGT topics. It is not adequate to just "size" the resistor to limit earth-fault current to say, 5A, 100A, or whatever value one thinks is appropriate! Even though an earth-fault may not be present the neutral still...

Mohan... certainly, just contact me off-list. Phil Corso (cepsicon [at] aol [dot] com)

SR... it is true that the distribution-type transformer in the NGT scheme adds an inductive component to neutral-current its effect is nil compared to the resistive component. Regards, Phil Corso

Bruce... the Mechanalog Analogy you alluded to in your 27-Nov-09 post was devised by Prof S.B. Griscom in 1926. A description can be found in the Westinghouse Transmission and Distribution Reference Book, ca 1950! If any one would like a copy of the article, please contact me off-list. But...