MR-REF & MR-REF3 Technical Manual
Issue 3, November 2013
Contents
1. P&B MR-REF & MR-REF3 ................................................................................................................................................................................. 1
1.1 Principle of operation ................................................................................................................................................................................... 2
Unbiased Differential .................................................................................................................................................................... 2
Restricted Earth Fault Protection for Transformers. ...................................................................................................................... 3
1.3 Displayed Feeder Data. ............................................................................................................................................................................... 4
1.4 Control Functions. ....................................................................................................................................................................................... 4
2. Technical Specification. ...................................................................................................................................................................................... 5
3. Environmental Tests. .......................................................................................................................................................................................... 6
4. Inputs and Outputs. ............................................................................................................................................................................................ 7
4.1. Power Supply Live. ..................................................................................................................................................................................... 7
4.3. Current Transformer Inputs. ....................................................................................................................................................................... 7
4.4. Output Relays............................................................................................................................................................................................. 7
4.5. Digital Inputs. ............................................................................................................................................................................................. 7
4.6. RS485 Rear Port. ....................................................................................................................................................................................... 7
4.7. RS232/USB Front Port. .............................................................................................................................................................................. 7
5. Faceplate Functions. .......................................................................................................................................................................................... 8
5.1 LED Status .................................................................................................................................................................................................. 8
6. LCD Display. ...................................................................................................................................................................................................... 9
6.1. Menu Screens. ........................................................................................................................................................................................... 9
6.2. Display Scroll............................................................................................................................................................................................ 10
6.3. Feeder Settings. ....................................................................................................................................................................................... 11
E/F CT Primary. ......................................................................................................................................................................... 11
6.4. Serial Settings. ......................................................................................................................................................................................... 12
6.5. I/O Settings (Input / Output Settings). ....................................................................................................................................................... 14
6.5.1 Digital Inputs ..................................................................................................................................................................................... 14
Reset Fault. ................................................................................................................................................................................ 14
Block. ......................................................................................................................................................................................... 14
6.5.2 Relay Outputs ................................................................................................................................................................................... 15
Trip............................................................................................................................................................................................. 15
Trip Fail Safe. ............................................................................................................................................................................. 15
Alarm. ........................................................................................................................................................................................ 15
Alarm Fail Safe. .......................................................................................................................................................................... 15
Healthy. ...................................................................................................................................................................................... 15
Healthy Fail Safe. ....................................................................................................................................................................... 15
Internal Fail. “Intrnl Fail” ............................................................................................................................................................. 15
Serial Timeout. "Ser Timeout" .................................................................................................................................................... 15
6.6. System Settings. ................................................................................................................................................................. 16
Password. .................................................................................................................................................................................. 16
Engineering Password ............................................................................................................................................................... 16
Change Password. ..................................................................................................................................................................... 16
Contrast and LCD Backlight. ...................................................................................................................................................... 16
Set Default Page / Default Return Time. ..................................................................................................................................... 16
Time Sync Delay. ....................................................................................................................................................................... 16
Software Version. ....................................................................................................................................................................... 16
Serial Number. ........................................................................................................................................................................... 16
Disturbance Recording Activation Key ........................................................................................................................................ 17
Time and Date............................................................................................................................................................................ 17
Chronovision .............................................................................................................................................................................. 17
Screen Saver and Screen Saver Time ....................................................................................................................................... 17
6.7. Protect Settings. ....................................................................................................................................................................................... 18
Function. .................................................................................................................................................................................... 19
Alarm. ........................................................................................................................................................................................ 19
Trip............................................................................................................................................................................................. 19
Block. ......................................................................................................................................................................................... 19
Reset. ........................................................................................................................................................................................ 19
Auto Reset. ................................................................................................................................................................................ 19
Panel-Reset. .............................................................................................................................................................................. 19
Serial-Reset. .............................................................................................................................................................................. 19
Remote-Reset. ........................................................................................................................................................................... 19
6.7.3. Restricted Earth Fault. ...................................................................................................................................................................... 20
6.7.6. Serial Timeout. ................................................................................................................................................................................. 20
6.7.7. Internal Error. ................................................................................................................................................................................... 20
6.8. Trip History. .............................................................................................................................................................................................. 21
6.9. Alarm History. ........................................................................................................................................................................................... 21
6.10. Last Five Faults. ..................................................................................................................................................................................... 21
6.11. Stats Info. ............................................................................................................................................................................................... 22
6.12. Calibration Menu. ................................................................................................................................................................................... 22
6.13. Disturbance Recording (OPTIONAL). ..................................................................................................................................................... 23
7. Menu Tree Structure ......................................................................................................................................................................................... 24
8 MR-REF & MR-REF3 Setting Sheets ................................................................................................................................................................. 25
8.1. MR-REF & MR-REF3 System Settings Summary. ......................................................................................................................................... 25
