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GEK - 105560

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3. OPERATION PRINCIPLES

The MLJ can be described as the function of a group of different units, each being responsible for one
part of the overall operation.

3.1 CONFIGURATION UNIT

The configuration unit allows us to select and change the following parameters:

• 

Frequency (50 or 60 Hz).

• 

Unit number.

• 

Communication speed.

 

3.1.1 GENERAL Settings

The configuration unit has the following settings:

0-1: f

Operation frequency
Range: 50 or 60
Units: Hz
Default value: 50

6-1: COM. ID

Unit number (relay identifier)
Range: 1-255
Default value: 1

6-2: COM. kbauds

Serial port baud rate
Range: 0.3, 0.6, 1.2, 2.4, 4.8, 9.6, 14.4, 19.2, 38.4
Units: kilobauds
Default value: 9.6

NOTE

: Settings 6-1 and 6-2 are the only ones that do no restart the protection since they only affect

communications. The rest of the protection settings restart the protection.

3.2  SYNCHRONISM CHECK UNIT

The main function of the MLJ is that of providing synchronism conditions for circuit breaker closures.
The synchronism check unit analyzes the voltage magnitudes at both side of the circuit breaker, and
the status of inputs and the settings, giving a synchronism signal if the conditions are met.

Depending on the status of the Manual input, this unit has two modes of operation: Manual mode and
Continuous mode. They are both described below.

Summary of Contents for MLJ1000

Page 1: ...G GE EK K 105560 105560 GE Power Management We bring good things to life MLJ MLJ1000 DIGITAL SYNCHRONISM CHECK RELAY...

Page 2: ...INPUT UNITS 15 3 5 SELF CHECK UNIT 15 3 5 1 Mode of Operation 15 3 6 OUTPUT UNITS 16 3 6 1 Mode of Operation 16 3 6 2 Settings 16 3 7 POWER SUPPLY 17 4 TECHNICAL CHARACTERISTICS 18 4 1 MODEL LIST 18...

Page 3: ...State of Line and buses 26 6 2 SEQUENCE OF SETTINGS 26 6 3 CALIBRATION SEQUENCE 28 6 4 SUMMARY OF SETTINGS 29 7 ACCEPTANCE TESTS 31 7 1 INTRODUCTION 31 7 2 VISUAL INSPECTION 31 7 3 INSULATION 31 7 4...

Page 4: ...1 40 FIGURE 7 BLOCK DIAGRAM 226B2201H1 41 The information provided herein does not intend to cover all details of variations of the described equipment nor does it take into account the circumstances...

Page 5: ...inuously Manual mode This is activated when voltage is applied through a manually activated input thus beginning synchronism control when voltage applied through another digital input for initial chec...

Page 6: ...carried out in a steady state that is with voltage magnitudes near or equal to the rated value close enable is not emitted for very low voltages Therefore for voltage of less than 9 volts the relay st...

Page 7: ...of accuracy in the installations measurement transformers etc Close enable Close enable is defined by three conditions in the system The difference in amplitude of the two voltage signals to be synchr...

Page 8: ...ds For applications where a preferred value for frequency slip does not exist it is recommended to use the maximum This way the behavior of other synchronism relays which do not have this feature can...

Page 9: ...th very similar operation in case of internal faults in both circuit breakers and channel transmission times less than 25 ms the slip setting may be set at 200 to 250 mHz In any case the order and ope...

Page 10: ...t time in synchronism relay A t8 End of synchronism relay time delay and internal output of synchronization enable t9 Reclose order of circuit breaker A t10 Closure of circuit breaker A t11 Resetting...

Page 11: ...e limits Voltage outside of limits Instantaneous or time delayed In order to do so the following should be set 1 The desired settings for the presence or absence of voltage in line and bus 3 1 to 3 4...

Page 12: ...auds Serial port baud rate Range 0 3 0 6 1 2 2 4 4 8 9 6 14 4 19 2 38 4 Units kilobauds Default value 9 6 NOTE Settings 6 1 and 6 2 are the only ones that do no restart the protection since they only...

Page 13: ...ker is open If all the synchronism conditions are met a time delay mechanism will be tripped and when the time limit is reached the synchronism signal SYNC will finally be obtained There are two diffe...

Page 14: ...Default value 10 0 2 1 SUP 27 ON OFF Undervoltage supervision enable Range Enabled or disabled Units Default value OFF Disabled 2 2 SUP 27 V Undervoltage threshold supervision Range from 10 to 180 in...

Page 15: ...tions Similar to what has been stated in the case of the synchronism unit if the Manual input is activated in order for the undervoltage units to operate it is necessary to also activate the Enable in...

Page 16: ...nchronism unit and gives way to the Enable input if that input is not active neither the synchronism nor the undervoltage will be activated When Manual mode is not desired simply disconnect the Manual...

Page 17: ...rnally the MLJ reads the signals sent from the following units the synchronism and synchronism failure signals supplied by the synchronism unit the undervoltage dead bus and line signals supplied by t...

Page 18: ...3 7 POWER SUPPLY The power supply circuit of the MLJ generates from the auxiliary voltage the internal voltages necessary for the operation of the relay The power supply isolates the internal circuitr...

Page 19: ...TECHNICAL CHARACTERISTICS FREQUENCY 50 and 60 Hz programmable by user NOMINAL VOLTAGE 63 to 220 Vac AUXILIARY POWER 24 28 Vdc 20 110 250 Vdc 20 MAXIMUM VOLTAGE ALLOWABLE Continuous 440 Vac TEMPERATUR...

Page 20: ...easurement unit may require up to 60 ms which will be added to the time delay introduced by setting this is typical behavior VOLTAGE CIRCUIT BURDEN Less than 0 15 VA at 110 V and 50 Hz or at 120 V and...

Page 21: ...55022 class B Magnetic fields According to IEC 100 4 8 class V Sinusoidal vibrations According to IEC 255 21 1 class II Shock test According to IEC 255 21 2 class II The MLJ relay complies with these...

Page 22: ...e removing the relay though it is not mandatory 5 2 INTERNAL CONNECTIONS External wiring is carried out in the two terminal blocks mounted in the rear part of the case Each terminal block contains 12...

Page 23: ...e user and to make it easier to set the relay LEDs In addition to the displays described above there are three LEDs which provide the following information READY green LED Relay available and protecti...

Page 24: ...of the relay voltage values frequency slip registers of the last close enable etc To operate simply push the ENTER button Setting Sequence allows consulting and changing of the operation settings of t...

Page 25: ...are in Function 0 of the Readout Sequence This function which will appear as soon as the button is released indicates the Status of the relay If the ENTER button is pressed a second time the second fu...

Page 26: ...ransitory and disappears the MLJ will reset and start up in the normal fashion 6 1 2 F1 F2 VL VB Voltage in line and buses These readings supply the RMS values of voltages in real time 6 1 3 F3 V Volt...

Page 27: ...egments show that the value of the voltage falls between the live and dead values These limits are determined by the settings in 3 1 to 3 4 The MLJ admits the live limit to be inferior to the dead lim...

Page 28: ...mHz We begin with the Readout Sequence display which gives us the line and bus activity and go to the Setting Sequence Display Press ENTER F0 appears on the display Without releasing it press Display...

Page 29: ...alibrated The calibration of this protection is done in the factory in a controlled environment with high precision equipment Therefore not only is it unnecessary to recalibrate the relay but also not...

Page 30: ...inuous mode timing 0 1 99 0 s 0 1 s 0 1 s 1 5 Manual mode timing 0 1 99 0 s 0 1 s 10 1 s 2 1 Voltage supervision enable OFF ON N A OFF 2 2 Voltage supervision threshold 10 180 V 1 V 40 V 3 1 Level pre...

Page 31: ...ALA Alarm If while in Readout Sequence the ENTER and buttons are pressed simultaneously the word CAL will appear briefly on the screen followed immediately by the average value of the line and bus vo...

Page 32: ...zing the relay from external interference during the insulation test approximately 7 mA for each capacitor is consumed In the event that the apparatus used to carry out the insulation test does not pe...

Page 33: ...o generate Close enable the same voltage 220 V for example is simply applied to the line and bus inputs 7 4 2 Angle unit test For the angle difference the default setting of 15 should be kept Apply co...

Page 34: ...on purposes see section 6 3 CALIBRATION SEQUENCE 7 8 GROUNDING The MLJ has a terminal B12 for grounding Connected to this terminal there is also a strip that connects the terminal to the relay case Th...

Page 35: ...the one that offers a better path for any overvoltage produced in the substation The disturbance could even come from the very ground cable and make a circuit to a ground with less potential through...

Page 36: ...GEK 105560 35 Figure 1 Logical diagram of Operation 226B2202H2...

Page 37: ...GEK 105560 36 Figure 2 Nameplate 226B1276H1...

Page 38: ...GEK 105560 37 Figure 3 Outline and panel drilling 226B6086H1...

Page 39: ...GEK 105560 38 Figure 4 Rear terminal plate 226B3205H1...

Page 40: ...GEK 105560 39 Figure 5 External connections 226B6265H1 Note The transformers can be connected to single or compound voltage...

Page 41: ...GEK 105560 40 Figure 6 Internal settings 301A7408H1...

Page 42: ...GEK 105560 41 Figure 7 Block Diagram 226B2201H1...

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