Install at least 3 the neutral earthing resistors and contactors – Yes we typically run the neutrals to a common neutral bar. – Yes, it is really problematic to solve its protection system – Anyone has any experience with diesel Genset paralleling on the common neutral resistor? How many generators can work connected to the resistor and how many can work isolated in parallel mode? That’s a very big open question.
I was reading on the internet it’s some old practice followed in the UK. – This is a star connection with y phase grounded Not an open delta. But as per the drawing seen some conflict. – Open delta connection, Yellow phase normally will ground. – Sorry open wye but the scheme is the same. – Such schemes are used in ungrounded systems or on generator – transformer sets. however should there be an earth fault and one of the phases hit the ground … you will get voltage across the open point – Typically the sum of the voltage across D7 and D9 is zero. – It’s mainly used as an input to detect earth faults using neutral voltage displacement. – That’s an open delta voltage transformer or potential transformer. – yes, in an oil company, usually they only use 2 PT inputs and make it as delta connection in the relay – Can u share nameplate details of the PT – Why b phase winding is grounded on the secondary side? – During one phase PT failure, will overflux relay work? Has anyone seen this kind of voltage transformer connection? To join our protection relay WhatsApp groups, please send “interest” on Whatsapp: protection relay 2 Discussion