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Manual MRM3-2 GB 

Woodward 

TD_MRM3-2_09.08_GB_Rev.New 

39 

5.12 Digital Inputs 

5.12.1 Parameter Set Changeover Switch 

 
When voltage is applied to this input it is changed over to the other parameter set. 
 

5.12.2 External Trigger of the Fault Recorder 

 
Via this input fault recording can be triggered without the MRM3-2 necessarily recognizing a trip. 
 

5.12.3 Recognition of “Motor Running” Condition 

 
This input can be used if the motor runs without load and does not need much current (I < 2% x 
IN). In such a case the motor current may lie below the STOP threshold and so recognition of the 
RUNNING conditions is not secure. In order to maintain the RUNNING conditions, voltage can be 
applied to this input by means of an aux. contact of the CB. This is necessary so that all functions 
which depend on the RUNNING conditions can operate faultless (e.g. I>> LAUF, I>, start counter 
etc.) and the LEDs are signaling the correct motor status. In such a case the under load element 
must not be used. (I< must be set to EXIT) 
 

5.12.4 Undelayed External Trip 

 
A trip is immediately triggered if voltage is detected by this input. The fault recorder is activated and 
the assigned output relay picks up. 
 

5.12.5 Delayed External Trip 

 
In principle this input has the same effect as the input for undelayed trip, but a trip is only triggered 
if the input signal was available during the entire adjusted delay time. 

 

 

Summary of Contents for SEG MRM3-2

Page 1: ...MRM3 2 Motor Protection Relay September 2008 Manual MRM3 2 Revision New...

Page 2: ...serves the right to update any portion of this publication at any time Information provided by Woodward Governor Company is believed to be correct and reliable However no responsibility is as sumed by...

Page 3: ...ng Delay for Thermal Overload 22 5 4 4 Heating Period Constant W and Cooling Down Time Factor C 22 5 4 5 t2x and t6x Minimal Trip Time During the Starting Process 23 5 4 6 Phase Undercurrent Element I...

Page 4: ...2 External Trigger of the Fault Recorder 39 5 12 3 Recognition of Motor Running Condition 39 5 12 4 Undelayed External Trip 39 5 12 5 Delayed External Trip 39 6 Notes on Relay Tests and Commissioning...

Page 5: ...ev New 5 7 4 3 Initial load factor 54 7 4 4 Tripping of t2x and t6x times 55 7 4 5 Inverse time over current protection 56 7 4 6 Trip characteristics 57 7 4 7 Inverse Time Characteristic for Load Unba...

Page 6: ...tics Short circuit protection Load unbalance supervision with definite or inverse trip characteristics Earth fault detection with suppression of harmonics The MRM3 2 recognizes the Start Up and Motor...

Page 7: ...teristics is selectable Definite element for short circuit high speed trip Single step earth fault supervision Load unbalance protection with inverse or definite trip characteristics NPS CB failure pr...

Page 8: ...ions Figure 3 1 Connection Diagram MRM3 2 Figure 3 2 Measuring of phase currents and earth current detection in Holmgreen connection IE This kind of connection can be used where three phase CTs are av...

Page 9: ...tities are galvanic decoupled analogously filtered and then fed to the analog digital converter 3 1 2 Output Relays The MRM3 2 has 5 output relays Two of these relays with two change over contacts and...

Page 10: ...trigger for the fault recorder 4 5 A6 Identification Motor Running 7 6 A7 Ext trigger undelayed 6 7 A8 Ext trigger delayed 5 3 1 4 Low High Range of the Digital Inputs The MRM3 2 is equipped with a wi...

Page 11: ...Manual MRM3 2 GB Woodward TD_MRM3 2_09 08_GB_Rev New 11 3 2 Front plate Figure 3 5 Front plate MRM3 2 IE Figure 3 6 Front plate MRM3 2 I...

Page 12: ...Number of motor starts CHAR Characteristics setting I Undercurrent setting I Over current setting I2 Load unbalance setting NPS I Short circuit setting IE Earth current setting CB CB failure protectio...

Page 13: ...or suppression of harmonics as well as suppression of DC components during the short circuit is used in the process The micro processor compares the existing current with the threshold value setting v...

Page 14: ...art Stop Threshold This threshold is fixed at 2 of IN Stop time The Stop time is adjustable in order to tolerate a brief off time of the current flow e g change over Star Delta from the START or RUNNI...

Page 15: ...has to be set at least for so long that the longest regular start procedure is covered RUNNING can be recognized in different ways If the START has been successfully completed This is the case when th...

Page 16: ...defined as parameters Example The motor should be allowed to be started three times an hour This means that in theory the motor can be started every 20 minutes 60 min 3 From this it can be concluded t...

Page 17: ...e for a start This start limitation is a dynamic one and is orientated on the data the thermal image is parameterized with For this the MRM3 2 detects the average thermal load of the latest starts Wit...

Page 18: ...in steady state condition is proportional to the square of the phase current e g ohmic losses and iron losses Q I oder I2 In the thermal image this temperature is described by the temperature equivale...

Page 19: ...nder full short circuit current the chosen transformers must not saturate in this current range This means that the overload factor must be sufficiently large Class For the nominal range or the lower...

Page 20: ...ermal su pervision AUTO Start No Chap 5 5 1 Auto definition of the remaining blocking time VARI Start block t Chap 5 5 3 CB failure protection CBFP CB t Chap 5 4 18 Inquiry of the fault memory FLT1 FL...

Page 21: ...he settings for the pick up value are adjusted to a multiple of the secondary rated CT current The settings for phase and earth current transformers can be done separately 5 3 2 Rated Frequency The FF...

Page 22: ...warning function the display does not show TRIP The relay assigned to this step responds and should therefore be configured onto a different relay than the one leading to tripping 5 4 3 Tripping Delay...

Page 23: ...ite time Undercurrent is only active during mode RUNNING The undercurrent element is also blocked if the measured current lies below the STOP threshold see chapter 4 1 EXIT is set then this element is...

Page 24: ...trip of the relay over current element is blocked The WARNING ALARM function is still active During this time LEDs I and t are red 5 4 10 Reset Mode for the Trip Characteristics in the Phase Current...

Page 25: ...ctive value of the current of the negative phase sequence sys tem I2 is calculated by the MRM3 2 When setting the threshold value for the load unbalance current I2 the indicated value referring to the...

Page 26: ...19 External Trip delayed Trip t Via the digital input A8 D8 an external trip with time delay can be activated Trip is initiated if the signal existed for at least the set time The external trip funct...

Page 27: ...his parameter is only visible if a time was selected chapter 5 5 1 It defines the time for a new start when the number of starts per interval was exceeded The following is possible VARI A new start is...

Page 28: ...ing current by the factor 0 707 the max imum starting time is doubled refer to Chapter 7 4 1 5 5 7 Start up recognition time or Motor Running time The start up recognition time is a criterion for swit...

Page 29: ...rwrite 4 00 3 33 S 4 Not to be overwritten 4 00 3 33 S 7 overwrite 2 00 1 66 S 8 Not to be overwritten 2 00 1 66 s total no of recordings Table 5 1 The storage zone of the fault recorder is designed a...

Page 30: ...for 4 s at 50 Hz and 3 33 s at 60 Hz 7 8 recordings for 2 s at 50 Hz and 1 66 s at 60 Hz will be overwritten when a new trigger signal occurs 5 7 3 Adjustment of the Trigger Event There is the choice...

Page 31: ...Y 00 month M 00 day D 00 time hour h 00 minute m 00 second s 00 Immediately when the supply voltage is applied the clock starts with the respective date and time The time is buffered against short te...

Page 32: ...ows To come to the blocking menu push buttons ENTER and TRIP are to be pressed at the same time The function being set is indicated by LEDs If necessary the blocking function can be changed with or an...

Page 33: ...etting Possible Settings LED Colour Overload warning AUTO HAND AUTO red IB x k Overload alarm AUTO HAND AUTO IB green IB x k Overload trip AUTO HAND AUTO IB green W green I Undercurrent alarm AUTO HAN...

Page 34: ...he time of the trip delay has elapsed The adjustment procedure is as follows Allocation of one or more of the 4 output relays to Alarm or Trip of each of the protective func tions Which of the functio...

Page 35: ...rm X _ 2 _ _ I red tI Tripping X 1 _ _ _ I red t red I2 Alarm X _ 2 _ _ I2 red tI2 Tripping X 1 _ _ _ I2 red t red IE Alarm X _ 2 _ _ IE red tIE Tripping X 1 _ _ _ IE red t red tCBFP Tripping _ _ _ _...

Page 36: ...t A Consequently the units displayed are changing i e for Phase Current Indicated as Range Unit Secondary current 000 40 0 x In Primary current 000 999 k000 k999 1k00 9k99 10k0 99k0 100k 999k 1M00 2M0...

Page 37: ...hing briefly the individual fault measuring values for the respective fault can be inquired by pressing SELECT RESET If the relay has not been reset after tripping TRIP is displayed measuring values c...

Page 38: ...tective function activated Otherwise TRIP remains in the display The set parameters are not changed by the reset procedure 5 11 1 Erasure of the Fault Memory For erasure of the fault memory the push b...

Page 39: ...conditions is not secure In order to maintain the RUNNING conditions voltage can be applied to this input by means of an aux contact of the CB This is necessary so that all functions which depend on...

Page 40: ...n be triggered by the TRIP push button Test procedure Entry Display Note TRIP DO1 Display of the relay software version part 1 TRIP 1 00 Display of the relay software version part 2 TRIP PSW Call for...

Page 41: ...f the tests can be carried out For testing the earth fault channel a single phase test should then follow For tests in Holmgreen connection simulation of an earth fault current has to be considered Co...

Page 42: ...ustment If the tripping characteristic for the max starting time is set to DEFT Definite Time tripping takes place after the set time has expired If the parameter is set to INVS Inverse Time Character...

Page 43: ...ular maintenance intervals at site From user to user these intervals may vary because among other things they depend on the type of relay the kind of appli cation significance of the object to be prot...

Page 44: ...at 50 Hz resp 13 33 s at 60 Hz Number of events 1 8 7 2 Common data Dropout to pickup ratio 97 Returning time 40 ms Time lag error class index E 20 ms Minimum operating time 40 ms Transient overreach...

Page 45: ...sformer ratio earth current Iprim E E SEK 0 002 50 0 kA Displayed in x IN Displayed in kA 0 002 0 200 0 200 0 500 0 500 1 00 1 00 2 00 2 00 5 00 5 00 10 0 10 0 20 0 20 0 50 0 0 001 0 002 0 005 0 01 0...

Page 46: ...g to current measur ing value or 30ms See EN 60255 3 Time limit W Start t2x t6x EXIT ab 2 x k IB ab 6 x k IB no limitation Cooling down fac tor C 1 00 8 00 x W 1 00 2 00 2 00 5 00 5 00 8 00 0 05 0 1 0...

Page 47: ...d to the measured current value or 30ms See EN 60255 3 Short circuit step at start I Start 0 5 40 EXIT Pick up value x IN during Start Step switched off 0 50 1 00 1 00 2 00 2 00 4 00 4 00 10 0 10 0 20...

Page 48: ...e or 10mA Characteristics I2 CHA R DEFT INVS definite DMT inverse IDMT 3 in relation to the meas ured current value or 30ms see EN 60255 3 Time delay characteristic pa rameter I2 t At DEFT 1 00 600 Tr...

Page 49: ...racteristics IE CHA R DEFT NINV VINV EINV RINV LINV RXIDG definite normal inverse very inverse extremely inverse RI inverse Long term inverse Special characteristic Time delay IE t at DEFT 0 04 260 Tr...

Page 50: ...T Switching delay in s No trip 0 04 1 00 1 00 2 00 2 00 5 00 5 00 8 00 8 00 10 0 10 0 20 0 20 0 50 0 50 0 100 100 200 200 260 0 02 0 05 0 1 0 2 0 5 1 0 2 0 5 0 10 0 20 0 3 of the set ting value or 25m...

Page 51: ...IT Start current at rated voltage x IN Function switched off 0 50 1 00 1 00 2 00 2 00 4 00 4 00 10 0 10 0 20 0 20 0 40 0 0 02 0 05 0 1 0 2 0 5 1 0 3 of the set ting value or 10mA Max Rated starting ti...

Page 52: ...r parameter Parameter LED Setting range Notes Range Step Tolerance Number of re cordings FR 1 3 7 2 4 8 Existing re cordings to be overwritten 1 x 8 s 6 66s 3 x 4 s 3 33s 7 x 2 s 1 66s Existing re cor...

Page 53: ...ic _ this applies if I I_Start 0 707 taus 2 x ts this applies if I I_Start 0 707 With taus tripping time ts starting time at rated starting current rated voltage or rated starting time I effective cur...

Page 54: ...I IB k p 1 with thermal time constant of the object to be protected I Relay current highest measuring value IB Basic current IP Initial load current p Initial load factor p 0 means cold operating com...

Page 55: ...g of t2x and t6x times Figure 7 3 Limitation of tripping time 2 x IN Figure 7 4 Limitation of tripping time 6 x IN 0 1 1 0 10 0 100 0 1000 0 1 10 0 5 min I IB k min 1 min 10 min 100 min 180 min 0 0 0...

Page 56: ...teristics acc to IEC 255 4 or BS 142 Normal inverse Type A 0 14 1 Very inverse Type B 13 5 1 Extremely inverse Type C 80 1 Long time inverse 120 1 RI inverse 1 0 339 0 236 RXIDG characteristics 5 8 1...

Page 57: ...mal Inverse Type A Figure 7 6 Very Inverse Type B 1 2 3 4 5 6 7 8 910 20 I IS 0 1 1 10 100 1000 t s tI 0 05 0 1 0 2 0 3 0 4 0 5 0 6 0 8 1 0 10 0 20 0 2 0 3 0 4 0 6 0 8 0 1 4 1 2 3 4 5 6 7 8 910 20 I I...

Page 58: ...ure 7 8 Long time inverse 1 2 3 4 5 6 7 8 910 20 I IS 0 01 0 1 1 10 100 1000 10000 t s tI 0 05 0 05 0 1 0 1 0 2 0 3 0 4 0 5 0 6 0 8 1 0 10 0 1 4 20 0 2 0 3 0 4 0 6 0 8 0 1 2 3 4 5 6 7 8 910 20 I IS 0...

Page 59: ...re 7 10 RXIDG characteristic 1 2 3 4 5 6 7 8 910 20 I IS 0 1 1 10 100 t s tI 20 0 10 0 8 0 7 0 6 0 5 0 4 0 3 0 2 0 1 0 0 8 0 7 0 6 0 5 0 4 0 3 0 2 0 1 0 05 1 2 3 4 5 6 7 8 910 20 I IS 0 1 1 10 100 t s...

Page 60: ...d Manual MRM3 2 GB 60 TD_MRM3 2_09 08_GB_Rev New Figure 7 11 Definite trip characteristic 1 10 I IN 0 01 0 1 1 10 100 t s tI tI I I tI tI 260 260 0 04 0 04 0 5 0 5 40 40 10 10 0 04 0 04 0 02 0 02 4 0...

Page 61: ...ed load unbalance in relation to IN I2S permanently permissible load unbalance in relation to IN Tripping characteristic Figure 7 12 Tripping characteristic 7 5 Output relays Contacts 2 change over co...

Page 62: ...ic for maximum starting time tripping delay of the thermal overload tripping warning for thermal overload Phase current 1 A rated current 5 A I1 I5 Earth fault current Without earth current element 1...

Page 63: ...E Default settings Year settings year X X Y 00 Month settings month X X M 01 Day settings day X X D 01 Setting of the hours hour X X h 00 Setting of the minutes minute X X m 00 Setting of the seconds...

Page 64: ...adstep X X trip W Start t2x and t6x min tripping time at a start X X EXIT W Time constant warming min X X 0 5m C Time constant cooling down X X 1 0 Warning element for thermal overload X X 20 I Pick u...

Page 65: ...value of the load unbalance element x IN X X 0 020 I2 CHAR Trip characteristic of the load unbal ance element X X DEFT I2 t Tripping time of the unbalanced load element s X X 1 0 I2 CHA R t Reset mod...

Page 66: ...time of engine 8rated start ing time with rated voltage s X X EXIT 0 I t Time of START recognition or MOTOR RUNNING s X X 0 20 0 I t Stopping time s X X 0 50 Parameters for the fault recorder LED Func...

Page 67: ...blocking trip Assignment of the reset functions LED Function Default setting Actual setting Set 1 Set 2 Set 1 Set 2 Overload warning AUTO AUTO IB Overload alarm AUTO AUTO IB W Overload trip AUTO AUTO...

Page 68: ...Actua tion X IB IB Alarm X IB W IB Trip X I I Alarm X I t I Trip X I I Alarm X I t I Trip X I Sta rt I Alarm at Start X I Sta rt t I Trip ping at Start X I I Alarm X I t I Trip X I2 I2 Alarm X I2 t I...

Page 69: ...Terminal Low plugged in High unplugged Default setting Actual setting D8 A2 Parameter set change over switch Plugged in D8 A5 Ext Trigger for the fault recorder Plugged in D8 A6 Recognition Motor Runn...

Page 70: ...Woodward Manual MRM3 2 GB 70 TD_MRM3 2_09 08_GB_Rev New AvK Gener tory s r o ul 4 kv tna 175 755 01 Vset n Czech Republic Tel 420 571 413 322 Internet http www woodward seg cz info woodward seg cz...

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