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Sandeep... a continuous voltage measurement across the EarthING-conductor (or GroundING-conductor) presumes a continuous current in the Earthing or Grounding Plane. This operation is a violation of the USA's NEC. I strongly suggest you implement the tests suggested by Bill Mostia...

Al... delay until vibration exceeds limit could be caused by air temperature-rise through fan. If you would like a Nomograph that calculates temperature-rise contact me off-forum! Regards, Phil Corso

Thiagarajan Sriram... what do your consultants say are the problem? 1) Please provide pertinent equipment parameters! 2) What is the failure frequency? 3) Are failures occurring on a specific phase? Or are all three phases involved? 4) Are failures random? 5) Are failures more...

Server... please send Phase and Line voltage and current values? Regards, Phil Corso

Trinity... has the problem existed since initial start-up? Regards, Phil Corso

Shetty... Excellent, thus far. Now provide some data regarding: driven machine; load (Amps); age; duty (27/7 or other); coolant inlet and outlet temp; coolant flow-rate; ambient temperature; motor temperature; speed; and what has been tried to correct problem, especially those suggested or...

Shujauddin... I suggest you search the Control.com Archives! Regards, Phil Corso

Win... repeating an earlier Caveat, "I no longer accept anonymous requests for information or help... something to do with the fact that anonymity breeds boorishness" Therefore, anyone requiring help must provide a name, affiliation with a company (or school) and a location! In return, I...

Abbs... following are the recommended lengths based on connection method used: 1) 2 wires per CT. The the total wire length is twice the distance, d, between the CT and protective or metering device(s), presuming the wires are in proximity to one another! 2) 3 wires, plus 4th as common...

Rob Parrsish... if the load circuits consist of 2 pairs of #10 AWG in the same enclosure, then the Ampacity is reduced to 80% of the values listed earlier!

Rob Parrish... NEC Ampacity for single-conductor #10 AWG, insulation rated for 90 deg C, and installed in free air, is 55 A. But, for 2-conductor, # 10 AWG, insulation rated for 60 deg C, installed in raceway (interpret enclosed), then Ampacity is only 40 A! For, 40 deg C, Ampacity is reduced...

Responding to Shetty's 23-Juk (14:54) question... There are a number of causes, To start with few: 1)Physical a) Brushes not diametrically-opposed. b) Brush "fingerprint" too large. c) Brushes out of line; Brushes loose in holder. d) Brush dimensions re different. 3) Electrical...

Manjunath... Did PRD operate shortly after arc-current was increased? 1) If so, can you provide listing of current-magnitudes at 1-minute intervals for the 15 minutes of operation? 2) And, then for 15-second intervals for the 1-minute period before the EAF tripped? Regards, Phil Corso...

Manjunath... are your questions about TTR, tan-delta, additional info, etc, being asked as part of an investigation to determine if: a) The PRD operated falsely? b) The EAF Xfmr did fail? Regards, Phil

Manjunath... Did the Buchholz Device operate as well? Regards, Phil Corso

Sedthawut... correction to my earlier reply: For the Dy11 configuration the voltage-ratio is (HV)/(sqrt[3]xLV), where HV and LV are the original primary and secondary line-voltages assigned the Dd configuration. For example, if the primary and secondary line-voltage ratio for the Dd xfmr...

Sedthawut... yes, assuming all phase-ends are accessible and reconnection is physically possible! However, it would result in a different voltage-ratio and different ultimate-capacity! That is, the ratio for the Dd0 is HV/LV, while the ratio of the reconnected Dy11, becomes (HV)/(LV/Sqrt[3])...

Marvalar... one can conduct a relatively simple calculation to determine if a "Loss-of-Load" disturbance will result in a situation requiring Over-Speed device intervention. Contact me off-list for additional information! Regards, Phil Corso (cepsicon [at] aol [dot] com)

Marvalar... the decision to trip the CB and not the turbine should be based on severity assigned the generator-fault. For a trip of relatively minor consequence, i.e., earth-fault, then enable CB tripping via reverse-power. Conversely, if the fault is over-current, then the CB is tripped...

Balakrishnan... contact me off list for some pointers! Phil Corso (cepsicon [at] aol [dot] com)