|Digital Energy > Protection & Control > Pilot and Distance Relays > GCY Phase Packaged Directional-distance relay
GCX51 is the type designation for a family of single phase, three-zone phase packaged relays. The first - and second-zone distance measurements are made by a unit having a reactance of ohm type characteristic and the third zone has a directional mho characteristic.
A GCY51F is a single phase mho relay with two zones of protection. The M1 and M2 units have a 75° angle of maximum torque and M1 has provision for 0.5 ohm offset phase to neutral. The M2 unit has provision for a forward offset 0-4 ohms phase to neutral, thus giving a conventional two-zone relay or a distinctive "figure eight" characteristic as required.
The GCXY51 is a single phase, four-zone phase distance relay with two zones or reactance characteristics. A third zone is provided by a unit having a directional mho characteristics, a
Long transmission lines
Directional Mho phase distance