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20

TB MRU3-1 12.00 E

6.5

Primary test

Generally, a primary injection test could be carried out
in the similar manner as the secondary injection test
described above. With the difference that the pro-
tected power system should be, in this case, con-
nected to the installed relays under test „on line“, and
the test voltages should be injected to the relay through
the voltage transformers with the primary side ener-
gized. Since the cost and potential hazards are very
high for such a test, primary injection tests are usually
limited to very important protective relays in the power
system.

Because of its powerful combined indicating and
measuring functions, the 

MRU1

 relay may be tested in

the manner of a primary injection test without extra ex-
penditure and time consumption.

In actual service, for example, the measured voltage
values on the 

MRU3-1

 relay display may be com-

pared phase by phase with the concerned indications
of the instruments of the switchboard to verify that the
relay works and measures correctly.

6.6

Maintenance

Maintenance testing is generally done on site at regu-
lar intervals. These intervals vary among users depend-
ing on many factors: e.g. the type of protective relays
employed; the importance of the primary equipment
being protected; the user's past experience with the re-
lay, etc.

For electromechanical or static relays, maintenance
testing will be performed at least once a year accord-
ing to the experiences. For digital relays like 

MRU3-1

,

this interval can be substantially longer. This is be-
cause:

 

the 

MR-

 relays are equipped with very wide self-

supervision functions, so that many faults in the relay
can be detected and signalised during service. Im-
portant: The self-supervision output relay must be
connected to a central alarm panel!

 

the combined measuring functions of 

MR-

relays en-

able supervision the relay functions during service.

 

the combined TRIP test function of the 

MR-

relay al-

lows to test the relay output circuits.

A testing interval of two years for maintenance will,
therefore, be recommended.
During a maintenance test, the relay functions includ-
ing the operating values and relay tripping times
should be tested.

Содержание MRU3-1

Страница 1: ...MRU3 1 AC voltage relay...

Страница 2: ...only 5 5 Parameter for the fault recorder 5 5 1 Adjustment of the fault recorder 5 5 2 Number of the fault recordings 5 5 3 Adjustment of trigger occurences 5 5 4 Pre trigger time Tpre 5 6 Date and t...

Страница 3: ...Features and characteristics Microprocessor technology with watchdog digital filtering of the measured values by using dis crete Fourier analysis to suppress higher harmonics and d c components induc...

Страница 4: ...asuring circuits are shown in the connection diagram The analog input voltages are galvanically decoupled by the input transformers of the device then filtered and finally fed to the analog digital co...

Страница 5: ...riting over If 2 4 or 8 recordings are chosen the complete memory is divided into the relevant number of partial segments If this max number of fault event has been exceeded the fault recorder block a...

Страница 6: ...rameters for the fault recorder FR Number of disturbance events FR Trigger events FR Pre trigger time Tvor Date and time Year Y 00 Month M 04 Day D 18 Hour h 07 Minute m 59 Second s 23 Additional func...

Страница 7: ...ting values for all parameters are stored in a parameter memory EEPROM Electrically Erasable Programmable Read Only Memory so that the actual relay settings cannot be lost even if the power supply is...

Страница 8: ...elta connection D 7 7 7 Sec winding of mains V T Figure 4 2 Input v t s in star connection Y 4 4 Blocking function No Dynamic Behaviour U U 1 voltage to external blocking input is ap plied free pro gr...

Страница 9: ...e time for each value U tU rated frequency setting value in Hz SELECT RESET fN U U 1 phase 3 phase U 1 U 3 SELECT RESET 1 3 Blocking function EXIT until max setting value until min setting value LED o...

Страница 10: ...an be correctly meas ured between 40 Hz and 70 Hz without adverse ef fects from the frequency With the setting f 50 60 Hz the measured voltage value is influenced by the frequency see Table 5 2 Declin...

Страница 11: ...d as parameter set change over switch With the setting R_S2 the reset input D8 E8 is used as pa rameter set change over switch With the setting B_FR the fault recorder is activated immediately by usin...

Страница 12: ...this ad justment the LED RS lights up 5 4 4 Setting of Baud rate applies for Modbus Protocol only Different transmission rates Baud rate can be set for data transmission via Modbus Protocol The rate...

Страница 13: ...failures min 6 minutes Note The window for parameter setting is located behind the measured value display The parameter window can be accessed via the SELECT RESET key 5 7 Indication of measuring valu...

Страница 14: ...the latest fault data set recorded At the same time the pa rameter set active at the occurence is shown By pressing SELECT RESET the fault measuring values can be scrolled By pressing it can be scroll...

Страница 15: ...LECT RESET in blocking mode again the assignment mode is selected The relays are assigned as follows LEDs U U U and U are two coloured and light up green when the output relays are assigned as alarm r...

Страница 16: ...be reset when the pickup is not present anymore otherwise TRIP remains in display During resetting of the display the parameters are not affected 5 9 3 Erasure of fault storage To delete the trip stor...

Страница 17: ...circuit breaker if tripping is not desired By pressing the push button TRIP once the display shows the first part of the software version of the relay e g D08 By pressing the push button TRIP twice t...

Страница 18: ...gu lation Voltage adjustable from 0 to 2 x UN Timer to measure the operating time Accuracy class 10 ms Switching device Test leads and tools 6 4 2 Example of the test circuit For testing of the MRU3 1...

Страница 19: ...n must not exceed 1 of the set operating value Furthermore gradually decrease increase the volt ages until the relay resets i e the voltage alarm output relay is disengaged Check that the dropout to p...

Страница 20: ...he relay works and measures correctly 6 6 Maintenance Maintenance testing is generally done on site at regu lar intervals These intervals vary among users depend ing on many factors e g the type of pr...

Страница 21: ...ime lag error class index E 10 ms Minimum operating time 30 ms Max allowed interruption of the auxiliarxy supply without effecting the function of the device 50 ms Influences on voltage measuring Aux...

Страница 22: ...0 V 2 200 V EXIT UN 230 V 2 460 V EXIT UN 400 V 4 800 V EXIT 0 04 50 s EXIT 1 V 1 V 2 V 0 01 0 02 0 05 0 1 0 2 0 5 1 0 2 0 s 1 of set value or 0 3 UN 1 or 15 ms 7 3 1 Interface parameter Function Para...

Страница 23: ...asuring of the positive phase sequence negative phase sequence and zero phase sequence system component 1 2 Rated voltage 100 V 230 V 400 V 1 2 4 Housing 12TE 19 rack Flash mounting A D RS 485 Alterna...

Страница 24: ...ernal triggering for the fault recorder SET1 Protection parameter Function Unit Default settings Set 1 Set 2 Actual settings Set 1 Set 2 1 3 1 phase 3 phase tripping U 1 U Pickup value for undervoltag...

Страница 25: ...the minute minute m 00 Clock Setting of the second second s 00 Blocking function Default settings Actual settings Blocking Not blocking Blocking Not blocking Parameter set Set 1 Set 2 Set 1 Set 2 Set...

Страница 26: ...Plugged Not plugged X No function X Code jumper Low High range for reset input Low High range for blockage input Default settings Actual settings Default settings Actual settings Low plugged X X High...

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