I have two nos 3.3/0.433 KV, 2000 kVA transformers in network having same percentage impedance (%Z) on nameplate. One is having load of 30% while other is 15%. when I try to connect these transformers by switching tie line on 0.433 kV side (HV sides are common bus), the transformer having higher load shares entire load and other gets totally unloaded. I have checked using tong tester. Can anybody explain the situation? Pl help.

 

Dilip... A large number of Posted Topics on this subject can be found in the Control List Archives.

If you don't find a suitable answer, then send the following measurements

o The three phase-to-phase voltages for each transformer, before with the tie-breaker open.

o The three phase-to-neutral voltages for each transformer

o The three secondary line-currents for each transformer

o The three primary phase-to-phase voltages.

o The Vector Groiup for each transformer.

o The Nameplate Listing of the primary winding taps.

Regards, Phil Corso (cepsicon [at] aol [dot] com)