Electrical Protection
Electrical Protection
(OP)
Hi..
I have one directional Earth fault(51N)relay that trips in the opposite direction(reverse)..
what must i do to trip in the direction that is supposed to be triping?
must i chang the VT or CT polarity?
Or must i chang Both?
Regards..
xuxu
I have one directional Earth fault(51N)relay that trips in the opposite direction(reverse)..
what must i do to trip in the direction that is supposed to be triping?
must i chang the VT or CT polarity?
Or must i chang Both?
Regards..
xuxu






RE: Electrical Protection
Any directional relay directionality can be reversed by reversing the current input wires.
RE: Electrical Protection
Change one quantity but not both.
However, there are relays that are dual polorized, so there are two directional quantities.
Why do you want to change it? Be sure it wasen't put that way for a reason.
RE: Electrical Protection
Could it actually be a non-directional element that is tripping.
67N is the directional number.
RE: Electrical Protection
What Raghun, Cranky and DiscoP said.
What is a your grounding system, what is a setting, what is a CT input connection ( residual connection of all 3xCT's or dedicated toroidal CT)?
Regards.
Slava