11 kv/400 v transformer phase problem !!
11 kv/400 v transformer phase problem !!
(OP)
we faced a problem in power plant consisted of 4 diesel generators 400 v synchronise togather and every generator connected to 400v/11kv delta/wye Transformer the synchronisation in low voltage side (400v) when we turn on the first generator it's transformer rise up the voltage to 11kv and this voltage delivered to all transformers in the high voltage side (11kv) but in each low voltage sides of each transformer there's only two phases live and the other one have 0 voltage ( we tested by voltmeter ) we tried by starting from other generator but it's the same problem. all the for transformers act like that (when we feed it from low voltage side it work perfectly but when we feed it from high voltage side there's missing phase in the other side (400)!! ... could u help me plzzz ???






RE: 11 kv/400 v transformer phase problem !!
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: 11 kv/400 v transformer phase problem !!
RE: 11 kv/400 v transformer phase problem !!
RE: 11 kv/400 v transformer phase problem !!
As David said, measuring from phase to ground without the generators running is not meaningful. The generators provide the only ground source, so when they are not running, there is no defined voltage from phase to ground. Measure the phase-to-phase voltages.
RE: 11 kv/400 v transformer phase problem !!
RE: 11 kv/400 v transformer phase problem !!
As others have said, you you measured phase to phase with a volt meter? (not your fingers!)
Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.
RE: 11 kv/400 v transformer phase problem !!
It is possible that someone used 240:120 PTs, phase to ground for the synchroscope rather than 400:120 PTs phase to phase.
That would probably give the symptoms as I understand them on an ungrounded delta system.
Bill
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"Why not the best?"
Jimmy Carter
RE: 11 kv/400 v transformer phase problem !!
L1=0,L2=400,L3=400 !!! does any one tell me y this transformer act like that ??!!
RE: 11 kv/400 v transformer phase problem !!
RE: 11 kv/400 v transformer phase problem !!
RE: 11 kv/400 v transformer phase problem !!
Other than that, look for some device that each transformer LV side has that is connected to ground in each instance.
Bill
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"Why not the best?"
Jimmy Carter