Siemens 7VK512

-AINTENANCE AND FAULT TRACING6+
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 -AINTENANCE AND FAULT TRACING
3IEMENS DIGITAL PROTECTION AND AUTOMATION RELAYS
ARE DESIGNED TO REQUIRE NO SPECIAL MAINTENANCE !LL
MEASUREMENT AND SIGNAL PROCESSING CIRCUITS ARE FUL
LY SOLID STATE AND THEREFORE COMPLETELY MAINTENANCE
FREE )NPUT MODULES ARE EVEN STATIC RELAYS ARE HER
METICALLY SEALED OR PROVIDED WITH PROTECTIVE COVERS
)F THE DEVICE IS EQUIPPED WITH A BACK
UP BATTERY FOR
SAVING OF STORED ANNUNCIATIONS AND THE INTERNAL TIME
CLOCK THE BATTERY SHOULD BE REPLACED AFTER AT MOST
 YEARS OF OPERATION REFER TO 3ECTION  4HIS REC
OMMENDATION IS VALID INDEPENDENT ON WHETHER THE
BATTERY HAS BEEN DISCHARGED BY OCCASIONAL SUPPLY
VOLTAGE FAILURES OR NOT
!S THE DEVICE IS ALMOST COMPLETELY SELF
MONITORED
HARDWARE AND SOFTWARE FAULTS ARE AUTOMATICALLY AN
NUNCIATED 4HIS ENSURES THE HIGH AVAILABILITY OF THE
RELAY AND ALLOWS A MORE CORRECTIVE RATHER THAN PRE
VENTIVE MAINTENANCE STRATEGY 4ESTS AT SHORT INTER
VALS BECOME THEREFORE SUPERFLUOUS
7ITH DETECTED HARDWARE FAULTS THE RELAY BLOCKS ITSELF
DROP
OFF OF THE AVAILABILITY RELAY SIGNALS EQUIPMENT
FAULT

2ECOGNIZED SOFTWARE FAULTS CAUSE THE PROCESSOR TO
RESET AND RESTART )F SUCH A FAULT IS NOT ELIMINATED BY
RESTARTING FURTHER RESTARTS ARE INITIATED )F THE FAULT IS
STILL PRESENT AFTER THREE RESTART ATTEMPTS THE PROCES
SOR SYSTEM WILL SWITCH ITSELF OUT OF SERVICE AND INDI
CATE THIS CONDITION BY THE RED ,%$
"LOCKED ON THE
FRONT PLATE $ROP
OFF OF THE AVAILABILITY RELAY SIGNALS
EQUIPMENT FAULT 
4HE REACTION TO DEFECTS AND INDICATIONS GIVEN BY THE
RELAY CAN BE INDIVIDUALLY AND IN CHRONOLOGICAL SE
QUENCE READ OFF AS OPERATIONAL ANNUNCIATIONS UNDER
THE ADDRESS  FOR DEFECT DIAGNOSIS REFER TO 3EC
TION 
)F THE RELAY IS CONNECTED TO A LOCAL SUBSTATION AUTO
MATION SYSTEM ,3! DEFECT INDICATIONS WILL ALSO BE
TRANSFERRED VIA THE SERIAL INTERFACE TO THE CENTRAL CON
TROL SYSTEM
%NSURE THAT THE CONNECTION MODULES ARE NOT
DAMAGED WHEN REMOVING OR INSERTING THE
DEVICE MODULES

7ARNING
 2OUTINE CHECKS
2OUTINE CHECKS OF INTERNAL FUNCTIONS OR PICK UP VAL
UES ARE NOT NECESSARY AS THEY FORM PART OF THE CON
TINUOUSLY SUPERVISED FIRMWARE PROGRAMS 4HE
PLANNED MAINTENANCE INTERVALS FOR CHECKING AND
MAINTENANCE OF THE PLANT CAN BE USED TO PERFORM OP
ERATIONAL TESTING OF THE PROTECTION EQUIPMENT 4HIS
MAINTENANCE SERVES MAINLY FOR CHECKING THE INTER
FACES OF THE UNIT IE THE COUPLING WITH THE PLANT 4HE
FOLLOWING PROCEDURE IS RECOMMENDED
2EAD OUT OF OPERATIONAL VALUES ADDRESS BLOCK
 AND COMPARISON WITH THE ACTUAL VALUES FOR
CHECKING THE ANALOG INTERFACES
(AZARDOUS VOLTAGES CAN BE PRESENT ON
ALL CIRCUITS AND COMPONENTS CONNECTED
WITH THE SUPPLY VOLTAGE OR WITH THE MEAS
URING AND TEST QUANTITIES

7ARNING
#IRCUIT BREAKER CLOSE CIRCUITS CAN BE TESTED DUR
ING TESTS OF THE MAIN PROTECTION EQUIPMENT 2E
SPECTIVE NOTES ARE GIVEN IN THE APPROPRIATE MANU
ALS OF THE MAIN PROTECTION RELAYS