![background image](http://html1.mh-extra.com/html/eaton/emr-3mp0/emr-3mp0_installation-operation-and-maintenance-manual_3982316179.webp)
4.11
Ex87 - External Differential Protection
By means of these elements, the protective device can detect and execute pickups and
trips that are issued by other external devices. This can be helpful, for logging purposes,
if the other device is not equipped with an event or waveform recorder. This might also be
helpful if the other device has no communication (SCADA) interface.
Ex87
ExtDiffProt_E91
2
Ex87 .
Trip
No assignment
1..n, Assignment List
Please Refer to Diagram: Blockings
(Element is not deactivated and no active blocking signals.)
Ex87 . Alarm
Ex87 .
Alarm
No assignment
1..n, Assignment List
AND
AND
Ex87 . Trip-I
Ex87 . Alarm-I
Ex87 . Trip
14
15
Yes
Ex87 .
Alarm only
No
AND
AND
Trip
↪ »Prot«
Pickup
↪ »Prot«
OR
AND
4.11.1
Commissioning: External Differential Protection
Object to be tested:
Test of the External Protection Module.
Necessary means:
Dependent on the application.
Procedure:
Simulate the functionality of the External Differential Protection (pickup, trip, and
blockings) by (de-)energizing the digital inputs.
Successful test result:
All external pickups, external trips, and external blockings are correctly recognized and
processed by the device.
179
www.eaton.com
EMR-3MP0
4 Protective Elements
4.11 Ex87 - External Differential Protection