Woodward SEG MRM3-2 Manual
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Woodward SEG MRM3-2 Manual

Motor protection relay
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MRM3-2 – Motor Protection Relay
(September 2008)
Manual MRM3-2 (Revision New)

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Summary of Contents for Woodward SEG MRM3-2

  • Page 1 MRM3-2 – Motor Protection Relay (September 2008) Manual MRM3-2 (Revision New)
  • Page 2 Woodward Manual MRM3-2 GB Woodward Governor Company reserves 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 Woodward Governor Company unless otherwise expressly undertaken ©...

  • Page 3: Table Of Contents

    Manual MRM3-2 GB Woodward Contents Introduction and Application ..............6     Characteristics and Features ..............7     Design ......................8     Connections ........................8     3.1.1 Analog Inputs ........................ 9     3.1.2 Output Relays ....................... 9  ...
  • Page 4 Woodward Manual MRM3-2 GB 5.5.7 Start-up recognition time or Motor Running time ............28     5.5.8 Stopping time ....................... 28     Interface Parameters ....................... 28     5.6.1 Adjustment of the Slave-Address (RS) ................ 28     5.6.2 Adjustment of the Baud-Rate (only for Modbus Protocol) ...........
  • Page 5 Manual MRM3-2 GB Woodward 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  ...

  • Page 6: Introduction And Application

    Woodward Manual MRM3-2 GB 1. Introduction and Application The motor protection relay MRM3-2 offers reliable protection for LV and MV motors which are ei- ther operated via power contactors or power circuit breakers. The following functions are integrated into this relay: •...

  • Page 7: Characteristics And Features

    Manual MRM3-2 GB Woodward 2. Characteristics and Features • Microprocessor technology with self-supervision, • Measuring of phase currents as RMS value, • Digital filtering of the earth current with discrete Fourier analysis, by which the influence of interference signals, such as harmonics and transient DC components during an earth- fault are suppressed.

  • Page 8: Design

    Woodward Manual MRM3-2 GB 3. Design Connections 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 available and a combination of phase and earth current measuring is required.

  • Page 9: Analog Inputs

    Manual MRM3-2 GB Woodward 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. 3.1.1 Analog Inputs The analog input signals of the phase currents I...

  • Page 10: Digital Inputs

    Woodward Manual MRM3-2 GB 3.1.3 Digital Inputs The MRM3-2 has 7 digital inputs with fixed functions. All inputs have a common reference point : Terminal D8. (See Chapter 3.1) Terminal Function Coding Plug External reset External blocking Parameter set change-over switch External trigger for the fault recorder Identification „Motor Running“...

  • Page 11: Front Plate

    Manual MRM3-2 GB Woodward Front plate Figure 3.5: Front plate MRM3-2-IE Figure 3.6: Front plate MRM3-2-I TD_MRM3-2_09.08_GB_Rev.New...

  • Page 12: Indicating Leds

    Woodward Manual MRM3-2 GB The LEDs , h, RS and FR on the MRM3-2 emit a yellow light, all other LEDs are bi-colored. The LEDs at the left next to the alphanumerical display give a green light during measuring and a red one when a fault signal occurs.

  • Page 13: Digital Part

    Manual MRM3-2 GB Woodward Digital part The protection relay is equipped with a powerful micro-controller, being the core element of the pro- tection unit. With this micro-controller all tasks are completely digitally processed, from discretisa- tion of the measuring quantities to protective tripping.

  • Page 14: Working Principle

    Woodward Manual MRM3-2 GB 4. Working Principle Start Recognition The MRM3-2 monitors the flow of the current from which the following operational conditions of the motor are gathered. • STOP • START • RUNNING Figure 4.1: Different Start-Up Behavior of Motors STOP - Condition: If no current can be measured (I <...
  • Page 15 Manual MRM3-2 GB Woodward Overload Threshold: This corresponds to the permissible thermal continuous current k x IB and is adjusted by the parameter of the thermal image. Starter Recognition Time: This adjustable time has only to be extended for special start procedures in order to prevent that the RUNNING conditions are indicated too early in advance.

  • Page 16: Criteria For Blocking The Start

    Woodward Manual MRM3-2 GB 4.1.1 Criteria for Blocking the Start Number of monitored starts : The MRM3-2 is equipped with a flexible supervision element which can limit the sequence of poss- ible starts. A start should be prevented if it is obvious that it is likely to be interrupted due to overload so that in total the down-time can be curtailed.
  • Page 17 Manual MRM3-2 GB Woodward Figure 4.4: Relation Start Period/Start Blocking Time with firm Start Blocking Time Thermal Image A start is always possible as long as there is enough thermal reserve 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.

  • Page 18: Starting Time

    Woodward Manual MRM3-2 GB Starting time With certain applications it is possible that the starting phase of the engines is extended. One rea- son for this insufficient terminal voltage which may be caused by the high starting current or by a high grid load in general.

  • Page 19: Requirement On The Main Current Transformers

    Manual MRM3-2 GB Woodward Requirement on the Main Current Transformers The CTs chosen have a considerable influence on the accuracy of the protective system. In order to select the right type of transformer, the requirements and conditions on site have to be consi- dered carefully.

  • Page 20: Operation And Adjustments

    Woodward Manual MRM3-2 GB 5. Operation and Adjustments Displayed text for parameter settings Function Displayed Text Related LED References Normal operation ϑ Exceeding the measuring range max. Sec. transf. currents indication L1, L2, L3,E Chap. 5.3.1 Rated frequency f = 50 / f = 60 Chap.

  • Page 21: Setting Procedure

    Manual MRM3-2 GB Woodward Setting Procedure <SELECT/RESET> short advancing the indication long reset <ENTER> Saving of an entry Before parameters can be set a password is inquired (see chapter 4.4 of description ”MR – Digital Multifunction Relay”). System parameters 5.3.1 Presentation of Measuring Values as Primary Quantities on the Dis-...

  • Page 22: Parameter Set Changeover Switch (P2)

    Woodward Manual MRM3-2 GB 5.3.6 Parameter Set Changeover Switch (P2) By means of this switch two different parameter sets can be activated. The changeover procedure can be realized either by the software or via the digital input (A2). If the parameter set changeover switch is adjusted to ”SET2“, the active parameter set can be changed to ”SET1“...

  • Page 23: T2X And T6X Minimal Trip Time During The Starting Process

    Manual MRM3-2 GB Woodward 5.4.5 t2x and t6x Minimal Trip Time During the Starting Process. With this parameter the fastest trip time during the start-up phase is limited for the thermal image. If the selected pick-up value k x I is exceeded by two times or six times, the characteristic breaks to definite time.

  • Page 24: Tripping Time Or Time Factor For The Phase Over Current Element (I>+T>)

    Woodward Manual MRM3-2 GB 5.4.9 Tripping Time or Time Factor for the Phase Over current Element (I>+t>) Normally, after change of the trip characteristics, the tripping time or the time factor also has to be changed accordingly. In order to avoid an unsuitable combination between trip characteristics and tripping time or time factor, the following measures are initiated by the MRM3-2: The LED for adjustment of the tripping time or time factor (I>...

  • Page 25: Negative Phase Sequence

    Manual MRM3-2 GB Woodward 5.4.12 Negative Phase Sequence Load unbalance can, for example, be caused by a phase failure or fault in a one motor winding. Load unbalances give rise to negative phase sequence currents in the stator, causing odd harmon- ics in the stator winding and even harmonics in the rotor winding.

  • Page 26: Tripping Time Or Time Factor For The Earth Fault Element (Ie>+T>)

    Woodward Manual MRM3-2 GB 5.4.16 Tripping Time or Time Factor for the Earth Fault Element (IE>+t>) The setting procedure outlined in chapter 5.4.9 applies here as well. 5.4.17 Reset Time for the Earth Fault Element (IE>+CHAR+t>) The setting procedure outlined in chapter 5.4.10 applies here as well.

  • Page 27: Start Supervision

    Manual MRM3-2 GB Woodward Start Supervision The MRM3-2 can offer two start supervision methods: • Automatically by means of the thermal load • By a limited number of starts per time interval 5.5.1 Duration of a Start Cycle (No.+Start) AUTO If this mode is selected, a start is always possible if sufficient start reserves are available according to the thermal image.

  • Page 28: Maximal Start Time (Start+T>)

    Woodward Manual MRM3-2 GB 5.5.6 Maximal Start Time (Start+t>) Exceedingly long acceleration can only be recognized if the threshold k*I is once overshot after the STOP threshold was exceeded. With the setting "DEFT" The time meter for the max. start time is activated upon exceeding of the threshold k*I >.

  • Page 29: Recorder (Fr)

    Manual MRM3-2 GB Woodward Recorder (FR) 5.7.1 Fault Recorder or Disturbance Recorder The existing store can be utilized in two ways: Not to be overwritten Previous recordings will not be overwritten. When there is no memory space left, further recordings are not possible.

  • Page 30: Number Of Fault Recordings

    Woodward Manual MRM3-2 GB Each of the storage segments have a fixed storage time where the time before the trigger event can be defined. Via the RS485 interface the data can be read out by means of a PC provided with HTL/PL-Soft4.

  • Page 31: Pre-Trigger Time

    Manual MRM3-2 GB Woodward Setting of the Clock When date and time are set, the LED „ “ is on. The following method is used: Date: year Y=00 month M=00 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.

  • Page 32: Additional Functions

    Woodward Manual MRM3-2 GB Additional Functions 5.9.1 Blocking of the Protective Functions Blocking of the protective functions After voltage has been applied to blocking input D8/E8, the intended reaction for each of the protective functions can be defined individually. (Observe voltage adjustment !) See chapter 3.1.4...

  • Page 33: Allocation Of The Reset Functions

    Manual MRM3-2 GB Woodward 5.9.2 Allocation of the Reset Functions When setting of the parameters for the blocking function is completed you are in the allocation mode for the reset functions. Whether the assigned relay should be reset manually or automatically after activation or trip can be allocated to each of the activation or trip elements.

  • Page 34: Allocation Of The Output Relays

    Woodward Manual MRM3-2 GB 5.9.3 Allocation of the Output Relays The MRM3-2 has five output relays. The fifth output relay is an alarm relay for the self-supervision and its al-location is fixed; it is operated acc. to the closed circuit principle.
  • Page 35 Manual MRM3-2 GB Woodward Relay functions Output relays Displayed Corresponding LED figures Symbol Function ϑ> Alarm _ 2 _ _ ϑ> red > x k Alarm _ 2 _ _ > green > x k Tripping 1 _ _ _ >...

  • Page 36: Measuring Value And Fault Indications

    Woodward Manual MRM3-2 GB 5.10 Measuring Value and Fault Indications 5.10.1 Measuring Value Indications The following measuring values can be displayed during normal operation: • Current in phase 1 (LED L1 green), • Current in phase 2 (LED L2 green), •...

  • Page 37: Fault Memory

    Manual MRM3-2 GB Woodward 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 MRM3-2 has a fault value memory covering up to 25 fault events. If this number is exceeded, the eldest data set is then overwritten.

  • Page 38: Reset

    Woodward Manual MRM3-2 GB 3. Values recorded after a tripping action • Tripping current in Phase 1, • Tripping current in Phase 2, • Tripping current in Phase 3, • Tripping value for earth current E, • Tripping value for load-unbalance current I2, •...

  • Page 39: Digital Inputs

    Manual MRM3-2 GB Woodward 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.

  • Page 40: Notes On Relay Tests And Commissioning

    Woodward Manual MRM3-2 GB 6. Notes on Relay Tests and Commissioning Connection of the auxiliary voltage To prevent destruction of the relay during tests the following has to be observed: • The aux. voltage supply of the relay must be within the permissible ranges.

  • Page 41: Test Circuit For Mrm3-2

    Manual MRM3-2 GB Woodward Test circuit for MRM3-2 For testing the MRM3-2 relays only one power source is necessary. Figure 6.1 shows a simple ex- ample of a single-phase testing circuitry with controllable power source for testing the unit. Figure 6.1: Test circuit 6.3.1 Checking of Input Circuits and of the Measuring Values...

  • Page 42: Testing The Pick-Up And Disengaging Values

    Woodward Manual MRM3-2 GB 6.3.3 Testing the Pick-Up and Disengaging Values For optimal protection many functions in this motor protection relay are interlinked and hence it is not possible to have all protective elements tested independently from each other. For all functions linked with the START/STOP/RUNNING recognition, a start simulation has to be performed so that the function can be tested under real conditions.

  • Page 43: Primary Test

    Manual MRM3-2 GB Woodward Primary Test As a rule, tests with currents at the CT primary side (real test) can be performed in the same way as tests with secondary currents. It is recommended to carry out primary tests only as an exception and only if it is absolutely necessary (for very essential protective facilities) because in some cases the costs involved and the strain on the system can be rather high.

  • Page 44: Technical Data

    Woodward Manual MRM3-2 GB 7. Technical Data Measuring input Rated data: Rated current I 1A or 5A Rated frequency f 50/60 Hz adjustable Power consumption in current path: at I = 1 A 0.2 VA at I = 5 A 0.1 VA...

  • Page 45: Setting Ranges And Steps

    Manual MRM3-2 GB Woodward Setting ranges and steps 7.3.1 System parameter *) One parameter can be marked by several LEDs Parameter LED * Setting range Range Step Tole- rance Transformer ratio L1 L2 L3 SEK Displayed in x I 0.002-0.200 0.001;...

  • Page 46: Time Over Current Protection

    Woodward Manual MRM3-2 GB 7.3.2 Time over current protection Parameter Setting range Notes Range Step Tolerance ±3% of setting Therm. Permissi- 0.20...4.00 0.01; ble contin. current EXIT Step switched 0.02; value k x I 0.05; or ±10mA 0.1 x I Overload factor 0.80...1.20...
  • Page 47 Manual MRM3-2 GB Woodward Parameter Setting range Notes Range Step Tolerance VINV very inverse EINV extremely in- RINV verse LINV RI-inverse Long-term in- verse Time delay I>+t> at DEFT: 0.04-1.00 0.02 ±3% of the set- 0.04 ...260 Time delay in s 1.00-2.00...

  • Page 48: Load Unbalance Protection

    Woodward Manual MRM3-2 GB 7.3.3 Load Unbalance Protection Parameter Setting Notes Range Step Tolerance range Load unbalance I2> Pick-up value nega- 0.020 0.050 0.001 ±3% of setting 0,02...1,00 tive phase sequence 0.050 - 0.100 0.002 value EXIT system 0.100 - 0.200 0.005...

  • Page 49: Earth Fault Protection

    Manual MRM3-2 GB Woodward 7.3.4 Earth fault protection Parameter Setting Notes Range Step Tolerance range ±3% of the set- Earth fault 0,01...2,0 pickup value x I 0.010 - 0.050 0.001 E> protection EXIT element blocked 0.050 - 0.100 0.002 ting value or 0.100 - 0.200...

  • Page 50: Circuit Breaker Failure Protection

    Woodward Manual MRM3-2 GB 7.3.5 Circuit breaker failure protection Parameter Setting Notes Range Step Tolerance range CB+t> 0.1...2.00 CB time 0.10-1.00 0.02 EXIT Step switched off 1.00-2.00 0.05 7.3.6 External trip delay Parameter Setting Notes Range Step Tolerance range Trip+t> 0,1...260 Switching delay in s 0.04-1.00...

  • Page 51: Start Parameter

    Manual MRM3-2 GB Woodward 7.3.8 Start parameter Parameter LED * Setting Notes Range Step Tolerance range ±2s for one Start blocking Start+N AUTO* Supervision by ther- start cycle reserve Supervision by inter- 1.0... 60.0 val time: Duration of the start...

  • Page 52: Interface Parameter

    Woodward Manual MRM3-2 GB 7.3.9 Interface parameter Parameter LED * Setting range Notes Step Tolerance 1 - 32 Slave-Address Baud-Rate 2400 4800 9600 */** Parity even even*/** odd* none* * selectable when Modbus Protocol is used ** fixed setting for RS485 7.3.10 Fault recorder parameter...

  • Page 53: Tripping Characteristics

    Manual MRM3-2 GB Woodward Tripping characteristics 7.4.1 Tripping characteristic for max. starting time The formula for calculating the tripping characteristic is: Inverse Time Characteristic · this applies if I/I_Start > = 0,707 = 2 x ts this applies if I/I_Start< 0,707...

  • Page 54: Thermal Image

    Woodward Manual MRM3-2 GB 7.4.2 Thermal image The formula for calculating the trip characteristics is as follows: τ · In for p · k τ with = thermal time constant of the object to be protected = Relay current (highest measuring value)

  • Page 55: Tripping Of T2X And T6X - Times

    Manual MRM3-2 GB Woodward 7.4.4 Tripping of t2x and t6x - times 1000,0 [min] 100,0 τ = 180 min τ = 100 min 10,0 τ = 10 min τ = 1 min τ = 0.5 min I / I Figure 7.3: Limitation of tripping time 2 x I...

  • Page 56: Inverse Time Over Current Protection

    Woodward Manual MRM3-2 GB 7.4.5 Inverse time over current protection Trip characteristics acc. to IEC 255-4 or BS 142 Normal inverse (Type A) 0.14 · Very inverse (Type B) 13.5 · Extremely inverse (Type C) · Long time inverse ·...

  • Page 57: Trip Characteristics

    Manual MRM3-2 GB Woodward 7.4.6 Trip characteristics 1000 I> 20.0 10.0 t[s] 0.05 5 6 7 8 910 Figure 7.5: Normal Inverse (Type A) 1000 I> 20.0 t[s] 10.0 0.05 5 6 7 8 910 Figure 7.6: Very Inverse (Type B)
  • Page 58 Woodward Manual MRM3-2 GB 10000 1000 t[s] I> 20.0 10.0 0.05 0.05 0.01 5 6 7 8 910 Figure 7.7: Extremely inverse (Type C) 10000 1000 I> t[s] 10.0 0.05 5 6 7 8 910 Figure 7.8: Long time inverse...
  • Page 59 Manual MRM3-2 GB Woodward I> 20.0 10.0 t[s] 0.05 5 6 7 8 910 Figure 7.9: RI-inverse I> 20.0 10.0 t[s] 0.05 5 6 7 8 910 Figure 7.10: RXIDG-characteristic TD_MRM3-2_09.08_GB_Rev.New...
  • Page 60 Woodward Manual MRM3-2 GB I> I> 0.02 0.02 t[s] > > 0.04 0.04 I>> I>> 40 40 10 10 >> >> 0.04 0.04 0.01 Figure 7.11: Definite trip characteristic TD_MRM3-2_09.08_GB_Rev.New...

  • Page 61: Inverse Time Characteristic For Load Unbalance

    Manual MRM3-2 GB Woodward 7.4.7 Inverse Time Characteristic for Load Unbalance Inverse current time protection With: t = tripping time [s] T = thermal time constant = measured load unbalance in relation to IN = permanently permissible load unbalance in relation to IN...

  • Page 62: Order Form

    Woodward Manual MRM3-2 GB 8. Order form Motor protection relay MRM3- with thermal image With additional features such as characteristic for maximum starting time, tripping delay of the thermal overload, tripping/warning for thermal overload Phase current rated current Earth fault current...
  • Page 63 Manual MRM3-2 GB Woodward Setting list for MRM3-2 Project: SEG-Job.-No.: Functional group: = Location: + Relay code: - Relay functions: Password: Date: All settings have to be checked at site and perhaps adjusted to the object to be protected. Date and time settings...
  • Page 64 Woodward Manual MRM3-2 GB Protection parameters Unit Default Actual setting setting Function Set1/Set 2 Set1 Set 2 Parameter set change-over switch SET1 > Basic current of the thermal overload 0.20 protection Constant 1.00 > + t> Excitation delay of the I >*k - steps...
  • Page 65 Manual MRM3-2 GB Woodward Protection Parameters (Contin.) Unit Default Actual setting setting Function Set1/Set2 Set1 Set2 I>> + Pick-up value for the phase short-circuit 0.50 Start element at start I>> + Tripping time of the phase short-circuit 0.04 Start + t>...
  • Page 66 Woodward Manual MRM3-2 GB Start parameters Unit Default Actual Function setting setting Function Set1/Set2 Set1 Set2 No.+Start Duration of a start cycle min. Number of starts per cycle Start+Bloc Start blocking time k+t> Start + Characteristic for the starting time...
  • Page 67 Manual MRM3-2 GB Woodward Assignment of the blocking functions Function Default setting* Actual setting Set 1 Set 2 Set 1 Set 2 ϑ> Overload warning NO_B NO_B > + τ Overload element NO_B NO_B I< Undercurrent element NO_B NO_B I>...
  • Page 68 Woodward Manual MRM3-2 GB Assignment of the Output Relays Function Relay 1 Relay 2 Relay 3 Relay 4 Default Actual Default Actual Default Actual Default Actual setting setting setting setting setting setting setting setting ϑ> ϑ> Actua- tion > > Alarm >...
  • Page 69 Manual MRM3-2 GB Woodward Setting of the Coding Plugs Coding plug Default Actual Default Actual Default Actual setting setting setting setting setting setting Plugged-in Unplugged No function No function Digital inputs Coding plug Function Low/High range for blocking input Terminal...
  • Page 70 Woodward Manual MRM3-2 GB AvK Generátory s.r.o. ul. 4. května 175 755 01 Vsetín (Czech Republic) Tel.: +420 571 413 322 Internet http://www.woodward-seg.cz info@woodward-seg.cz TD_MRM3-2_09.08_GB_Rev.New...

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