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Yes, there is! It's called "Reacceleration!" Regards, Phil Corso (cepsicon [at] aol [dot] com)

Jojo, while I agree there are several possibilities OOP is high on my list of for the following reasons: A) Its relativity easy to trouble-shoot. B) The problem has persisted from start-up. C) Voltage mismatch would not produce such high reactive current. D) High VAr was mentioned...

Romulo Rodriguez... Typically the same protective relaying job can have PTs with different ratios depending on the primary voltage they are to measure. Some are connected to read Phase-voltages while others are connected to read Line-voltages! Regards, Phil Corso

It appears that the two source PTs supplying voltage signals to the synchronizer are improperly connected, resulting in an Out-Phase-Closure. Please contact me On- or Off-List with detail on the GSU xfmr. Phil Corso

Absolutely necessary. Did you read the two referenced topics? Phil

Has problem appeared recently, or has it been present since commissioning of the two units? Regards, Phil Corso

Shamyl,... What I meant by "drying-out" was, did you apply current via a low voltage source at one end of the cable, with the other end short-circuited? Regards, Phil Corso (cepsicon[at]aol[dot]com)

Shamyl... did you try drying out insulation prior to testing? Following are two Control List Topics to review: o 1001509379 "Dielectric Testing" o 1026230152 "IR Measurement of Cables" Regards, Phil Corso (cepsicon[at]aol[dot]com))

Christina... of course the best data comes from the manufacturer. If unavailable, then go with an IEEE Standard such as 141, 241, or 551. Also contact transformer manufacturers. If you need a number quickly, then use 3.00 if unit is three-phsse, and 2.00 if single-phase. Regards, Phil...

Blackstoneboy, of course the current increases, but that's not the point. A major problem is to protect the generator against a ground-fault current which will, in general, exceed its 3-ph fault current. It has nothing to do with synchronization or anything else. I will repeat what had been...

Blackstoneboy: a) the NGR has no effect on synchronization of generators; b) it is used to reduce phase-to-ground fault current magnitude and eliminate system over-voltages; and, c) for the system you submitted, both NGRs can remain connected at all times. The reason for switching of NGR...

Road Surfer... the data you provided indicates that max design kVAr (lagging) is about 136 (omitting any deliberate margin of error). Then, if max spinning reserve load is limited to 30MW, the machine produces about 139MVA. The corresponding armature current is about 87% of design, which...

Faisal... contact me off-forum for a list of reference texts that will help you! Regards, Phil Corso (cepsicon[at]aol[dot]com)

Adil... voltage data provided confirm supply is not the cause of the problem. VUF is about 0.3 percent. Also, analysis indicates input power is about 83-84% of the motor's rating. If you wanted additional proof that the problem is internal, then determine the motor's...

Faizal... do you mean what construction-types are permissible? Or how to size the transformer? Regards, Phil Corso (cepsicon [at] aol [dot] com)

Curt, surely you didn't mean to imply in your 08-Oct-09 (13:46) post that the wye-point in the starter should be grounded... or did you? Regards, Phil

Adil, the data you provided thus far, indicates that the supply voltage VUF (Voltage-Unbalance-Factor) is nil, while the line current AUF (Amperage-Unbalance-Factor) is 15.9% or 16.6% per NEMA or IEC Standards, respectively. The data rules out supply voltage unbalance as the cause. Instead...

Adil, what is motor's rated current? Phil Corso

Rushi, the current direction is arbitrary. But, choosing one direction is less prone to error! Regards, Phil Corso

Adil... What are the 3 phase-to-phase, and the 3 phase-to-neutral voltages? Regards, Phil Corso(Cepsicon[at]aol[dot]com)