GE MLJ, Manual

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: ...4 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 4 2 TECHNICAL CHARACTERISTICS 18 4 3 INSULATION 19 4 4 TYPE TESTS 20 5 DESCRIPTION OF HARDWARE 21 5 1 CASE 21 5 2 INTERNAL CONNECTIONS 21 5 3 IDENTIFICATION 21 5 4 MLJ FRONT DEVICES 21 6 OPERATION OF...

Page 3: ...VB 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 SYNCHRONISM UNIT 31 7 4 1 Voltage unit test 32 7 4 2 Angle unit test 32 7 5 UNDERVOLTAGE UNIT 32 7 6 CONTINUOUS AND MANUAL MODE TESTS 33 7 7 CALIBRATION 33 7 8 GROUNDING 33 ...

Page 4: ...H1 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 that may be present in your installation operating or maintenance activities Should you wish to receive additional information or for any particular problem which cannot be solved by referring to the...

Page 5: ...tinuously 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 checking The function of synchronism with voltage in the line and bus can be controlled by two undervoltage units which allow the synchronism operation when both voltages are higher than the set value Ad...

Page 6: ...s 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 stops measuring phase and frequency not giving permission to close under such conditions The MLJ also offers additional insensitivity to frequency measurement concerning harmonics since this is done v...

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 synchronized defines a circle shifted from the axis of abscissa a distance equal to the magnitude of the minimum vector and having a maximum radius equal to the difference V The angular difference allowed e...

Page 8: ...or 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 be reproduced If a preferred value for the voltage difference does not exist it is recommended to use the maximum rating in doing so closure is permitted monitoring only conditions of phase slip and time ...

Page 9: ...ith 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 operating times of the different elements involved should be observed these are the elements with which the synchronism check relay must be coordinated and whose typical magnitudes are shown on the foll...

Page 10: ...me 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 of synchronism relay A t12 End of output enable of synchronism relay A 1 Opening time of circuit breakers 60 ms 2 Spark quenching time 20 ms 3 Additional waiting time for discrepancies in opening of circu...

Page 11: ...he 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 2 The enable settings of the undervoltage unit 4 2 to 4 4 3 The control setting for voltage in line and bus 2 2 4 The enables for the synchronism unit and synchronism control 4 2 and 2 1 5 The config...

Page 12: ...bauds 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 breake...

Page 13: ...aker 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 different settings for the time delay mechanism If Manual input is not activated it will remain in Continuous mode and the time delay mechanism will work based on the first setting setting 1 4 t cont If o...

Page 14: ...ds 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 steps of 1 Units volts Default value 40 4 1 25 ON OFF Activation of the synchronism check unit Range Enabled or disabled Units Default value OFF Disabled 3 2 3 Failure of Closure Conditions In orde...

Page 15: ...ations 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 input However as opposed to the synchronism check unit this undervoltage unit has no time delay whatsoever 3 3 2 Settings The undervoltage unit has the following assigned settings 3 1 VL Level of volta...

Page 16: ...ynchronism 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 and Enable inputs leaving the terminals corresponding to these two inputs free 3 5 SELF CHECK UNIT While operating the synchronism and undervoltage units the MLJ continuously carries out internal ch...

Page 17: ...ernally 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 the undervoltage unit and finally the alarm signal given by the self check unit If there is a synchronism or undervoltage signal this unit will activate the Close enable relays If there is an Alarm si...

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 circuitry from external perturbations for both industrial and high frequencies The power supply is effective over a wide range and is a switching type power supply ...

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 TEMPERATURE RANGES Operating 25ºC to 55ºC Storage 40ºC to 65ºC Comply with IEC standard 255 6 for the 25º to 55ºC interval and ANSI C37 90 specifying the 25º to 55ºC interval AMBIENT HUMIDITY Up to 95 without c...

Page 20: ... measurement 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 60 Hz DIGITAL INPUTS BURDEN 24 to 48 Vdc model 30 kOhm 110 to 220 Vdc model 136 kOhm AUXILIARY POWER SUPPLY BURDEN Idle 3W NC alarm relay activated only Tripped 6W all relays activated WEIGHTS Net ...

Page 21: ...N 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 regulations which include the GE standard of insulation and electromagnetic compatibility and the standards required for the Community Standard 89 336 for the European Community CE label under the h...

Page 22: ...re 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 terminals with screws M3 metric 3 mm diameter see figure 4 There is no internal wiring given that the relay is made up of a removable card with a connector designed for directed insertion into the te...

Page 23: ...he 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 protection enabled 52 Red LED indicating close enable condition 27 Red LED indicating undervoltage condition ...

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 the MLJ All three buttons are used for this operation Calibration Sequence this function gives the average of the line and bus voltages to assist in calibration Immediately after connecting the relay ...

Page 25: ...e 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 function F1 will appear This function shows the value of the line voltage and will be seen as soon as the ENTER button is released In this fashion pressing and releasing the ENTER button we can go through...

Page 26: ...ansitory 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 Voltage difference module The relay vectorially subtracts the line and bus voltages the modulus of the subtraction is what is represented in this reading See the graphic of phasors in the APPLICATION secti...

Page 27: ... segments 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 limit In these cases both the upper as well as the lower segments can be lit up 6 2 SEQUENCE OF SETTINGS In order to introduce or modify the settings it is necessary for the relay to be in the Setting ...

Page 28: ...0 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 1 1 the buttons can now be released We now go to the setting 1 3 Press Display 1 2 Press Display 1 3 we have achieved the desired setting Now we will modify it Press ENTER Display 20 blinking these ...

Page 29: ...calibrated 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 recommended The relay has a single gain calibration by means of a potentiometer see figure 6 ...

Page 30: ...ontinuous 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 present of voltage in line VL 40 245 V 1 V 50 V 3 2 Level absent of voltage in line VL 10 180 V 1 V 30 V 3 3 Level present of voltage in bus VB 40 245 V 1 V 50 V 3 4 Level present of voltage in bus VB...

Page 31: ...e 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 voltages By applying a known voltage for example 60 RMS to both the line and bus inputs the trimmer is adjusted see figure 5 until a reading of 60 0 on the display is obtained If we now press the ENTER...

Page 32: ...izing 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 permit such a consumption the test will be done by grouping less terminals These tests are only carried out on new relays A new relay means one that has not been in service whose expedition date is not...

Page 33: ... 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 15º should be kept Apply continuous voltage to input 52b simulates open circuit breaker Apply 60 V to the line and bus inputs these should be in phase The Close enable contacts should be closed and the red LED 52 Close enable l...

Page 34: ...ion 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 This strip improves the discharge path of interference and must always be connected it must not be disconnected even when an insulation test is being performed Grounding is done with a cable that leads...

Page 35: ...e 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 the interference capacities with the panels In any case for personal safety the equipment cases must always be grounded Doubts about the grounding of equipment often arise not grounding can in some c...

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 ...