Coupling devices for rotor ground-fault protection

7XR81 coupling unit is the necessary accessory for the rotor ground-fault protection with the SIPROTEC 7UM62 and SIPROTEC 7UM85 machine protection relays.

This device replaces the previous 7XR6100-0*A00 coupling unit and the 3PP1336-0DZ series resistor in one device.

7XR8004 resistor coupling unit is the necessary accessory for the 1 to 3 Hz rotor ground-fault protection together with the 7XT71 (1 to 3 Hz) generator and the SIPROTEC 7UM62 and SIPROTEC 7UM85 machine protection relays.

This device replaces the previous 7XR6004-0*A00 resistor unit, allowing higher excitation voltages at a reduced size.

7XR86 coupling unit is used for the 90%-stator ground-fault protection with the SIPROTEC 7UM62 and SIPROTEC 7UM85 machine protection relays.
The voltage divider is necessary at grounding or neutral-transformer application with a higher secondary voltage than 200 V (e.g. 500 V) of the protection relay's voltage-inputs maximum voltage (e.g. 100 V).

This device replaces the previous 3PP1336-1CZ-K2Y (5:1, 5:2 voltage divider) resistor unit. The 7XR86 has the same construction like the 7XR8004. Only the resistors of the 7XR8004 have been replaced.

7XR87 coupling unit is used for interfacing the excitation voltage of a generator to the DC measurement inputs of the SIPROTEC 7UM62 and SIPROTEC 7UM85 machine protection relays.