background image

24

TB MRM3  07.01 E

5.10.2

Units of the Displayed Measuring

Values-

Indication of the measuring value can be represented in
the display optionally as multiple of the secondary rated
current (x In) or as primary current (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 – 2M00

A
kA*
kA
kA
kA
MA

* for rated transformer current starting at 2kA

Earth Current

Indicated as

Range

Unit

Secondary current .000 – 15.0

x In

Primary earth cur-
rent

.000 – 999.
k000 – k999
1k00 – 9k99
10k0 – 99k0
100k – 999k
1M00 – 2M00

A
kA*
kA
kA
kA
MA

* for rated transformer current starting at 2kA

5.10.3

Indication of the Fault Data

All fault events acquired by the relay are optically indi-
cated on the front cover. For the 

MRM3

 the four LEDs

(L1, L2, L3, I2; E) and the functional LEDs (

ϑ

>; I

B

>; I<;

I>, I>>, I2> and I

E

>) are provided. Not only fault sig-

nals are put out but also the activated protective function
is indicated. If, for instance, overcurrent occurs, the LEDs
assigned to the respective phases are flashing.  LED I>
comes on also at the same time. After elapse of the trip-
ping time the flashing LEDs change to permanent light.

5.10.4

Fault Memory

In case of actuation or tripping of the relay, the fault
values and times are stored in a voltage fail-safe way.
The 

MRM3

 has a fault value memory covering up to 25

fault events. If this number is exceeded, the eldest data
set is then overwritten.

Besides the tripping values, the LED states are also
saved for fault indication.

Inquiry of the fault memory

When the <-> push-button is pressed during normal
measuring value indication, the fault data is displayed.

FLT1

last fault

FLT2

fault before last

etc.
By pressing <+> the respective fault can be selected.

During fault value indication FLT

 

it can be changed over to another fault data set by
pressing <+> or <->

 

it is displayed, which of the parameter sets was ac-
tive during the event

 

the LEDs are falshing according to the stored pick-up
values/trip information, i.e. LEDs showing a permant
light when the trip occured, start to flash in order to
indicate that is was a past fault condition. Those
LEDs, which were flashing when the trip occured,
(element was actuated) are flashing briefly

 

the individual fault measuring values for the respec-
tive fault can be inquired by pressing
<SELECT/RESET>

If the relay has not been reset after tripping (TRIP is dis-
played), measuring values cannot be indicated.

The fault memory can be cleared by pressing the button
combination <SELECT/RESET> and <-> for about 3s. In
the display „wait“ is shown.

Summary of Contents for MRM3

Page 1: ...MRM3 Motor Protection Relay ...

Page 2: ...rt 5 4 10 Negative Phase Sequence 5 4 11 Earth Fault Element IE 5 4 12 Trip Characteristics for the Earth Fault Element IE CHAR 5 4 13 Tripping Time or Time Factor for the Earth Fault Element IE t 5 4 14 Reset Time for the Earth Fault Element IE CHAR t 5 4 15 Tripping Time for the CB Failure Protec tion CB t 5 4 16 External Trip delayed Trip t 5 4 17 Trip Blocking in case of Excessive Phase Curren...

Page 3: ... Test 6 5 Maintenance 7 Technical Data 7 1 Measuring input 7 2 Common data 7 3 Setting ranges and steps 7 3 1 System parameter 7 3 2 Time overcurrent protection 7 3 3 Load Unbalance Protection 7 3 4 Earth fault protection 7 3 5 Circuit breaker failure protection 7 3 6 External trip delay 7 3 7 Trip blocking beginning with the adjusted rated current 7 3 8 Start parameter 7 3 9 Interface parameter 7...

Page 4: ... which the influence of interference signals such as harmonics and transient DC com ponents during an earth fault are suppressed Two sets of parameters Operating hour meter Complies with the requirements of IEC 255 8 VDE435 part 301 1 for overload relays Definite time undercurrent protection Selectable protective functions Definite time over current protection DMT and inverse time overcurrent prot...

Page 5: ...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 available and a combination of phase and earth current measuring is required Figure 3 3 Measuring of earth current with core type CT IE With the combination of phase and earth current measuring CTs to be connected according to Figure 3 2 and Figure 3 3 ...

Page 6: ...re operating according to the n o princi ple with the exception of the self supervision relay which operates acc to the n c principle 3 1 3 Digital Inputs The MRM3 has 7 digital inputs with fixed functions All inputs have a common reference point Terminal D8 See Chapter 3 1 No Terminal Function Coding Plug 1 C8 External reset 2 2 E8 External blocking 1 3 A2 Parameter set change over switch 3 4 A5 ...

Page 7: ... the earth current I2 Indication of the unbalanced load current NPS ϑ Indication of the temperature equivalent h Operating hour meter Date and time 3 2 2 Adjusting LEDs IB Rated motor current K Constant quantity k IB 100 thermal load τW Heating period constant τC Cooling down factor t Tripping times generally ϑ Switching threshold of the thermal overload alarm No Number of motor starts CHAR Charac...

Page 8: ...ization of the measur ing quantities to protective tripping With the protection program stored in the program storage EPROM the micro processor processes the voltages applied to the analog inputs and from this calculates the fundamental harmonics of the current Digital filtering DFFT Discrete Fast Fourier Transforma tion for suppression of harmonics as well as suppres sion of DC components during ...

Page 9: ... the START or RUNNING conditions STOP is only indicated if the current was under 2 IN for longer than the stop time Based on this time the running down period can be considered in a certain way for the LED indication START Condition START is only recognised if the previous condition was STOP and the motor current has exceeded the start threshold If the STOP or RUNNING conditions are recognised the...

Page 10: ...Resistance start if after STOP a motor current has settled between 2 IN and k x IB and the start recognition time has elapsed The overload threshold has not nec essarily to be exceeded soft start If the Motor Running input was activated but the overload threshold is not or not any longer ex ceeded See Chapter 5 12 3 With the recognition of STOP the RUNNING condi tions have ceased to exist Figure 4...

Page 11: ... long enough then even more than three starts an hour might be possible because the motor was able to cool down in the mean time The delay can be firmly defined through start blocking time or be automatically ascertained VARI until the 20 min utes given in the example are over The state of the thermal image has no influence on the delay Figure 4 3 Relation Start Period Start Blocking Time Figure 4...

Page 12: ...e rise of the thermal image From the average of the last two successful starts the unit detects the start load After overload conditions the thermal image is only re leased when the motor has cooled down far enough to deal with the demand of a new start 4 3 Requirement on the Main Current Transformers The CTs chosen have a considerable influence on the accuracy of the protective system In order to...

Page 13: ...sion 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 15 Inquiry of the fault memory FLT1 FLT2 Trip type dependent Chap 5 10 3 Erase fault memory wait Chap 5 10 4 Relay tripped TRIP Trip type dependent Reset the system SEG Password inquiry PSW LED of the set parameter Hidden password XXXX Chap 5 2 Paramet...

Page 14: ... of the earth current 5 3 3 Operating Hour Meter h As soon as the conditions START or RUNNING have been recognised the operating hour meter starts The meter can also be preset Years and hours are shown in two windows After every 8760 h the value is car ried over to the window Year In the display the years are marked with the letter Y engl year 5 3 4 Number of Motor Starts No Every start is counted...

Page 15: ...efinite 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 switched off The time delay for the undercurrent element is set to seconds Note The time delay must not be set shorter than the STOP time otherwise every time the motor is stopped an undercurrent...

Page 16: ... be set to the same value so there is no differentiation If it is set to EXIT then the respective element is switched off Irrespectively of the selected trip characteristics for I the short circuit high speed trip element I has a trip ping time which does not depend on the current This time applies for both elements I START and I RUNNING 5 4 10 Negative Phase Sequence Load unbalance can for exampl...

Page 17: ...existed for at least the set time The external trip func tion can be allocated to a relay 5 4 17 Trip Blocking in case of Excessive Phase Current Trip Block This function is important where power contactors are used and they are not designed to disconnect high short circuit currents In such a case no function of the MRM3 must initiate tripping The trip function is then allocated to a preceding pro...

Page 18: ... speeds Baud rates 5 6 3 Adjustment of the Parity only for Modbus Protocol For adjustment of the parity there are three options even even parity odd odd parity no no check of the parity 5 7 Fault Recorder FR 5 7 1 Fault Recorder The existing store can be utilised in two ways Not to be overwritten Previous recordings will not be overwritten When there is no memory space left further recordings are ...

Page 19: ...n four different trigger events P_UP PickUP Data saving begins when a general activation is recognised TRIP Data saving begins when a general trip is recognised A_PI After Pickup Data saving begins when the last acti vation threshold is undershot recog nises for instance CB failure protec tion TEST Data saving is activated when push buttons and are pressed simultaneously immediately upon pressing ...

Page 20: ...ws 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 and saved with ENTER Perhaps a password has to be entered Proceed to the next function with SELECT RESET After selection of the last blocking function settings for the 2nd parameter set can follow For al...

Page 21: ... Symbol Protective Functions Default Setting Possible Settings LED Colour ϑ Overload warning AUTO HAND AUTO ϑ red IB Overload alarm AUTO HAND AUTO IB green IB τW Overload trip AUTO HAND AUTO IB green τW green I Undercurrent alarm AUTO HAND AUTO I red tI Undercurrent trip AUTO HAND AUTO I red t red I Overcurrent alarm AUTO HAND AUTO I red tI Overcurrent trip AUTO HAND AUTO I red t red I Start Short...

Page 22: ...p 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 functions Which of the function is just being processed is sig nalled by the LEDs In addition to the protective functions special purpose signals can be given by the relays Startblock Start is not recommended START Motor is starting LAUF Motor in op...

Page 23: ... _ Trip red t red Start Block Start blocking X _ _ 3 _ Start green Block green Start Motor starting _ _ _ _ Start green Operation Motor running X _ _ _ 4 S R green Start time Excessive start ing time X 1 _ _ _ Start green t red Table 5 6 Example of an Allocation Matrix of the Output Relays Default Setting 5 10 Measuring Value and Fault Indications 5 10 1 Measuring Value Indications The following m...

Page 24: ...ge to permanent light 5 10 4 Fault Memory In case of actuation or tripping of the relay the fault values and times are stored in a voltage fail safe way The MRM3 has a fault value memory covering up to 25 fault events If this number is exceeded the eldest data set is then overwritten Besides the tripping values the LED states are also saved for fault indication Inquiry of the fault memory When the...

Page 25: ...tor because it is still hot but the pro tective unit proceeds on the assumption that the motor is cold 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 necessarily recognising a trip 5 12 3 Recog...

Page 26: ...iggered 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 enter the password PSW TRI Password entry Ready for tests TRIP TRIP Start the test Release of self test relay Pick up of all output relays Test of all LEDs Select Reset SEG Finish the test Output relays retu...

Page 27: ... vated because it cannot be tested with three equal phase currents Three phase conductor current test For this test a relevant three phase test source 120 phase shift must be available Each channel of the source is connected with one conductor current input This test circuitry is recommended because with this most of the tests can be carried out For testing the earth fault channel a single phase t...

Page 28: ...o recognise the simulated run ning condition firstly The test source must be able to copy the course of the motor current exactly as it is in reality The required test short circuit current can only be injected after the MRM3 has recognised the running condition The test conditions of the other elements i e I I I Start I RUNNING have to be adjusted according to the application of the selected para...

Page 29: ... 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 application significance of the object to be protected previous experience of the user etc For electro mechanical or static relays normally an an nual check is required For the MRM3 the maintenance intervals can be much longer because the MRM3 relays are provided wi...

Page 30: ...s at 50 Hz bzw 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 T5ransient overreach at instantaneous operation 5 Permissible interruption of the supply voltage without affecting the relay function 50 ms Influences on the current measurements Auxiliary voltage in the range of 0 8 UH...

Page 31: ...rrent Iprim E E SEK 0 002 50 0 kA Displayed in x IN Displayed in kA 0 001 0 002 0 005 0 01 0 02 0 05 0 1 0 2 Operating hour meter h Y 00 28 years 1 year h 0000 8759 hours 1 hour Motor starts No 0000 9999 Number of starts 1 Rated frequency f 50 f 60 Hz LED flashing after activa tion NOFL FLSH no yes Date and time Y 00 99 M 01 12 D 01 31 h 00 23 m 00 59 s 00 59 Year Month Day depends on month Hour M...

Page 32: ...05 0 1 0 5 1 0 2 0 5 0 10 0 20 0 s 3 of the setting value or 20ms Overcurrent I 0 2 4 0 EXIT Pick up value x IN Step switched off 0 01 0 02 0 05 0 1 x IN 3 of the setting value or 10mA Characteristics I CHAR DEFT NINV VINV EINV RINV LINV definite normal inverse very inverse extremely inverse RI inverse Long term inverse 0 02 0 05 0 1 0 5 1 0 2 0 5 0 10 0 20 0 s 0 01 0 02 0 05 0 1 0 2 3 of the sett...

Page 33: ...h fault protection Parameter LED Setting range Step Tolerance Earth fault protection IE 0 01 2 0 EXIT pickup value x IN element blocked 0 001 0 002 0 005 0 01 0 02 0 05 x IN 3 of the setting value or 0 5 of the rated value Characteristics IE CHAR DEFT NINV VINV EINV RINV LINV RXIDG definite normal inverse very inverse extremely inverse RI inverse Long term inverse Special characteristic Time delay...

Page 34: ...r one start cycle faded out in AUTO No 1 20 Permitted starts per pe riod 1 faded out in AUTO Start Block t VARI 1 0 60 Remaining interval time Fixed start blocking time min 1 0 min 3 of the setting value or 20ms Start recognition time Start t 0 02 500 Earliest RUNNING rec ognition s 0 02 0 05 0 1 0 5 1 0 2 0 5 0 10 0 s 3 of the setting value or 20ms max starting time Protective function againsst p...

Page 35: ...e overwritten 1 x 8 s 6 66s 3 x 4 s 3 33s 7 x 2 s 1 66s Existing recordings not to be overwritten 2 x 8 s 6 66s 4 x 4 s 3 33s 8 x 2 s 1 66s Trigger event FR P_UP TRIP A_PI TEST At actuation At trip After actuation Test recording with button and Pre trigger time FR 0 05 8 00 Duration of the previous event S All given times refer to 50 Hz 60 Hz in brackets ...

Page 36: ...rrent highest measuring value IB Basic current IP Initial load current p Initial load factor p 0 means cold operating component k Constant 7 4 2 Initial load factor Presentation of the trip with variable initial load factor τ 1 k I I p k I I ln t 2 B 2 2 2 B 2 aus 1 1 25 1 5 1 75 2 2 25 2 5 I IB 0 01 0 02 0 04 0 06 0 08 0 1 0 2 0 4 0 6 0 8 1 2 t aus τ p 0 2 p 0 3 p 0 4 p 0 5 p 0 6 p 0 7 p 0 8 p 0 ...

Page 37: ... 0 100 0 1000 0 1 10 τ 0 5 min I IB k min τ 1 min τ 10 min τ 100 min τ 180 min Figure 7 2 Limitation of tripping time 2 x IN 0 0 0 1 1 0 10 0 100 0 1000 0 1 10 τ 0 5 min τ 1 min τ 10 min I IB k min τ 100 min τ 180 min Figure 7 3 Limitation of tripping time bei 6 x IN ...

Page 38: ...1 02 0 Is I 14 0 t Very inverse Type B s I t 1 Is I 5 13 t Extremely inverse Typ C t I Is t I s 80 2 1 Long time inverse s t 1 Is I 120 t I RI inverse s t I I 236 0 339 0 1 t I S RXIDG characteristics s t I I n 3 1 8 5 t I S l Where t Tripping time tI Time multiplicator I Fault current Is Setting value of the current ln natural logarithm ...

Page 39: ... 1000 t s tI 0 1 0 2 0 3 0 4 0 5 0 6 0 8 1 0 1 4 2 0 3 0 4 0 0 6 6 0 8 0 10 0 20 0 0 06 Figure 7 5 Very Inverse Type B 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 1 0 2 0 3 0 4 0 5 0 6 0 8 1 0 1 4 2 0 3 0 4 0 6 0 8 0 10 0 20 0 0 06 Figure 7 6 Extremely inverse Type C 1 2 3 4 5 6 7 8 910 20 I IS 0 1 1 10 100 1000 10000 t s tI 1 0 2 0 10 0 8 0 6 0 5 0 4 0 3 0 0 8 0 6 0 5 0 4 0 ...

Page 40: ...1 10 100 t s tI 8 0 6 0 3 0 4 0 2 0 1 6 1 0 1 4 1 2 10 0 0 8 0 6 0 5 0 4 0 3 0 2 0 1 0 05 Figure 7 9 RXIDG characteristic 1 10 I IN 0 01 0 1 1 10 100 t s I tI I tI 4 0 260 0 06 1 0 40 2 0 0 06 0 2 Figure 7 10 Definite trip characteristic 7 6 Output relays Contacts 2 change over contacts for relays 1 and 2 1 change over contact for relays 3 4 This information is subject to technical alterations ...

Page 41: ...image MRM3 Phase current 1 A rated current 5 A I1 I5 Earth fault current Without earth current element 1 A rated current 5 A E1 E5 Housing 12TE 19 rack door installation A D Communication protocol RS485 Pro Open Data Modbus RTU M Leave box empty if option is not desired ...

Page 42: ...er of motor starts X X 0000 50 60 Hz X X 50Hz Actuation indication X X FLSH Protection parameters Unit I IE Default set ting Actual setting LED Function Set1 Set 2 Set1 Set 2 P2 Parameter set change over switch X X SET1 IB Basic current of the thermal overload protection x IN X X 0 20 k Constant X X 1 00 τW Start t2x and t6x min tripping time at a start X X EXIT τW Time constant warming min X X 0 ...

Page 43: ...th fault element X 0s CB t Tripping time CB failure protection s X X EXIT Trip t Tripping time external trip s X X 0 10 Block Trip Trip blocking at excessive phase current x IN X X EXIT Start parameters Funktion Unit I IE Default set ting Actual set ting LED Function Set1 Set2 Set1 Set2 No Start Duration of a start cycle min X X 30 No Number of starts per cycle X X 10 No Start t Start blocking tim...

Page 44: ...ocking actuation TR_B blocking trip Assignment of the reset functions Default setting Actual setting LED Function Set 1 Set 2 Set 1 Set 2 ϑ Overload warning AUTO AUTO IB Overload alarm AUTO AUTO IB τW Overload trip AUTO AUTO I Undercurrent alarm AUTO AUTO I t Undercurrent trip AUTO AUTO I Overcurrent alarm AUTO AUTO I t Overcurrent trip AUTO AUTO I Start Short circuit alarm at start AUTO AUTO I Sh...

Page 45: ... Actual setting ϑ ϑ Actuation X IB IB Alarm X IB τW IB Trip X I I Alarm X I t I Trip X I I Alarm X I t I Trip X I Start I Start Alarm X I I Alarm X I t I Trip X I2 I2 Alarm X I2 t I2 Trip X IE IE Alarm X IE t IE Trip X CB CB failure protection Trip Ext trip undelayed X Trip t Ext trip delayed X Start Block Start blocking X Start Motor is starting S R Motor is running X Start t Excessive start up t...

Page 46: ...lugged 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 Running Plugged in D8 A7 Ext trip undelayed Plugged in D8 A8 Ext trip delayed Plugged in D8 C8 Reset function Plugged in D8 E8 Blocking function Plugged in This technical description applies as from the use of Software...

Reviews: