HI, MY FRIEND ASKED ME TO LOOK AT THEIR PROBLEM ABOUT THE LED "ERROR" INDICATION IN ONE OF THEIR 7SD522 LINE DIFFERENTIAL RELAYS. THE RELAY'S RUN AND ERROR LEDS ARE BOTH  ILLUMINATED AT THE SAME TIME.

THE SCREEN'S DISPLAY ARE AS FOLLOWS:

MONITOR 

*****************************

Equipment data -> 1

User Interface ->     2

System I-face ->      3

Reset                        4

SIEMENS intern      5

Basing on the screen displayed indication, I concluded that there is an internal error, perhaps the hardware or software inside the relay. Then after that I read the manual (7SD52 v4.2).

The manual said, that the relay will reset and restart, and will attempt to restart again if the fault is not cleared but will automatically take itself out of service if after 3 consecutive restarting attempts within 30 sec if the error is not cleared.

From the display screen, it seems that the relay has already attempted the reset-restart sequence and failed because we cannot communicate with the relay using the front serial interface anymore.

But all the displayed indications on the screen did not exactly fit on any item from the list of fault reactions of the device as shown in Table 2-5 on page 148 of the manual.

SO OUR QUESTIONS ARE:

1.) IS THE RELAY ALREADY USELESS BECAUSE IT TOOK ITSELF OUT OF OPERATION?(DUE      TO THE INTERNAL ERROR)  OR

2.) IS THE PROTECTION STILL WORKING IN THE BACKGROUND WITH THE ERROR                 INDICATED?(BECAUSE MAYBE IT WAS ONLY THE SYSTEM INTERFACE COMPONENT THAT WAS AFFECTED WITH THE PROTECTION DATA INTERFACE STILL OK)?

THOUGH THE PROTECTED LINE HAS SECOND MAIN PROTECTION ELEMENT (21) THEY DON'T WANT TO TOUCH THE RELAY/TEST THE RELAY BY SECONDARY INJECTION BECAUSE THE SAID LINE IS THE ONLY LINE IN OPERATION (THE OTHER LINE IS CURRENTLY ON MAINTENANCE).

WE HOPE THAT SOMEBODY HERE COULD CLEAR THE DUST INSIDE OUR MINDS REGARDING THE ISSUE.

THANKS IN ADVANCE

Hi!

Did you get the assist with this situation ?? I am facing the same situation.