Woodward MRN3 Series, Manual

Page 1: ...MRN3 Mains decoupling relay September 2008 Manual MRN3 Revision New...

Page 2: ...rves 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 W...

Page 3: ...n storage FLSH NOFL 25 5 3 5 Parameter switch external trigger for the fault recorder 25 5 4 Protection parameters 27 5 4 1 Parameter setting of over and under voltage supervision 27 5 4 2 Number of m...

Page 4: ...oltage functions 39 6 5 3 Checking the relay operating time of the over undervoltage functions 39 6 5 4 Checking the operating and resetting values of the over under frequency functions 40 6 5 5 Check...

Page 5: ...tection functions in one device the MRN3 is a very compact mains decoupling device Compared to the standard used single devices it has a very good price performance ratio For applications where the si...

Page 6: ...and vector surge measuring display of all measuring values and setting parameters for normal operation as well as tripping via a alphanumerical display and LEDs display of measuring values as primary...

Page 7: ...transformers of the device then filtered and finally fed to the analog digital converter The measuring circuits can be applied in star or delta connection refer to chapter 4 3 1 3 1 2 Blocking input T...

Page 8: ...d saved in a cyclic buffer It is possible to store 1 8 fault occurrences with a total recording time of 16 s with 50 Hz and 13 33 s with 60 Hz per channel Storage division Independent of the recording...

Page 9: ...paces 6 7 and 8 are occupied this example shows that the memory has been as signed more than eight recordings This means that No 6 is the oldest fault recording and No 4 the most recent one Figure 3 3...

Page 10: ...rotection parameters Setting parameter MRN3 1 MRN3 2 U X X tU X X U X X tU X X U X X tU X X U X X tU X X T X X f1 X X tf1 X X f2 X X tf2 X X f3 X X tf3 X X df X dt X 1 3 X X UB X X RS485 Slave X X Bau...

Page 11: ...located behind the measured value display The parameter window can be accessed via the SELECT RESET key 3 3 LEDs All LEDs except LED RS min and max are two colored The LEDs on the left side next to th...

Page 12: ...Woodward Manual MRN3 GB 12 TD_MRN3_09 08_GB_Rev New 3 4 Front plate Figure 3 4 Front plate MRN3 1 Figure 3 5 Front plate MRN3 2...

Page 13: ...ency harmonics and d c components caused by fault induced transients or other system disturbances The micro processor continuously compares the measured values with the preset thresholds stored in the...

Page 14: ...al voltage of the input transformers Dependent on the application the input transformers can be connected in either delta or star The connection for the phase to phase voltage is the delta connection...

Page 15: ...parallel with the mains e g industrial internal power supply plants should be separated from the mains when failure in the intra system occurs for the following rea sons It must be prevented that the...

Page 16: ...s are able to pickup within 200 ms but they cannot prevent power to rise to short circuit values too Since power changes are also caused by sudden loaded alternators the use of power relays can be pro...

Page 17: ...loaded a rotor displacement angle is build between the terminal voltage mains voltage U1 and the synchronous internal voltage Up Therefore a voltage is difference U is built between Up and U1 Fig 4 4...

Page 18: ...ed with the electrical fielded mains power and therefore the synchronous speed keeps constant Fig 4 5 Figure 4 6 Voltage vectors at mains failure In case of mains failure or auto reclosing the generat...

Page 19: ...o passage occurs either earlier or later The established deviation of the cycle duration is in compliance with the vector surge angle If the vector surge angle exceeds the set value the relay trips im...

Page 20: ...urge relay reacts upon the first load change causing a vector surge and trips the mains C B For detecting high resistance mains failures a minimum current relay with an adjustable trip delay can be us...

Page 21: ...nstantane ously released instantane ously released after 1 s released after 5 s released after 5 s 3 supply voltage is switched on blocked for 200 ms blocked for 200 ms blocked for 1 s blocked for 1 s...

Page 22: ...in volt setting value in seconds SELECT RESET one time for each value U tU overvoltage high set tripping delay of high set element setting value in volt setting value in seconds SELECT RESET one time...

Page 23: ...L1 L2 or L3 MRN3 1 Delete failure memory wait SELECT RESET Enquiry failure memory FLT1 FLT2 L1 L2 L3 U U U U f Ddf dt Save parameter SAV ENTER Save parameter SAV ENTER for about 3 s Trigger signal fo...

Page 24: ...3 2 Y Switch over Depending on the mains voltage conditions the input voltage transformers can be operated in delta or Y connection Changeovers are effected via the and the keys and stored with ENTER...

Page 25: ...es are always measured in one period Sample rate setting is fixed to 50 Hz or 60 Hz 16 samples per 20 ms or 16 67 ms are always measured 5 3 4 Display of the activation storage FLSH NOFL If after an a...

Page 26: ...via the blocking input and or the fault recorder via the reset input The relevant func tion is then activated by applying the auxiliary voltage to one of the external inputs With the setting R_FR the...

Page 27: ...th an adjustable measuring repetition When the instantaneous fre quency measuring value exceeds at over frequency or falls below at under frequency the set reference value the counter is incremented o...

Page 28: ...ccurs only if the vector surge angle exceeds the set value in all three phases We recommend to choose the one phase tripping logic 1Ph Only if this adjustment is too sensi tive adjustment 3Ph should b...

Page 29: ...recommend a setting value for dt of minimum 4 cycles 5 4 7 Voltage threshold value for frequency and vector surge measuring df dt at MRN3 2 Correct frequency measuring or vector surge measuring canno...

Page 30: ...ces P_UP Pickup Storage is initiated after recognition of a general activation TRIP Storage is initiated after a trip has occurred A_PI After Pickup Storage is initiated after the last activation thre...

Page 31: ...nder voltage step 2 BLOC red U Overvoltage step 1 NO_B red U Overvoltage step 2 NO_B red f1 Frequency step 1 BLOC red f2 Frequency step 2 BLOC rec f3 Frequency step 3 NO_B red Vector surge BLOC red df...

Page 32: ...signed sepa rately to the relays The assignment mode can be terminated at any time by pressing the SELECT RESET push button for some time abt 3 s Note The function of jumper J2 described in general de...

Page 33: ...ripping delay it is possible that the stored min max val ues are higher than the tripping threshold without causing a trip The reason for this is storage of instantaneous values Min Max measuring of t...

Page 34: ...he oldest data set is written over For fault indication not only the trip values are re corded but also the status of LEDs Fault values are indicated when push buttons or are pressed during normal mea...

Page 35: ...umper position J3 ON Manual Reset Pressing the push button SELECT RESET for some time about 3 s Electrical Reset Through applying auxiliary voltage to C8 D8 Software Reset The software reset has the s...

Page 36: ...h button ENTER thus entering into the setting mode Now set the parame ters U and U to EXIT to block the undervoltage functions After that press the SELECT RESET for app 3 s to reset the LEDs and TRIP...

Page 37: ...eutral voltage will be applied to the voltage input circuits while the phase to phase voltages will be connected to the voltage input circuits in case of a delta connection The vol tage in put connect...

Page 38: ...energizing the MRN3 relay during test The three phase voltages are applied to the relay in Y connection Figure 6 1 Test circuit For testing the vector surge function of the relay a test circuit which...

Page 39: ...ay measures only the fundamental component of the input signals the harmonics will be rejected by the internal DFFT digital filter Whereas the RMS metering instrument measures the RMS value of the inp...

Page 40: ...over under frequency functions can be tested in the similar manner as in chapter 6 5 3 for over under voltage functions 6 5 6 Checking the vector surge function With the help of an advanced relay test...

Page 41: ...cking input of the re lay terminals E8 D8 Inject a test voltage which could cause tripping for the testes functions Ob serve that there is no trip and alarm for those functions Remove the auxiliary su...

Page 42: ...switchboard to verify that the relay works and measures correctly 6 7 Maintenance Maintenance testing is generally done on site at regular intervals These intervals vary among us ers depending on many...

Page 43: ...r class index E 10 ms Minimum operating time 40 ms Max allowed interruption of the auxiliary supply without a facting the function of the device 50 ms Influences on voltage measuring Aux voltage in th...

Page 44: ...60 V EXIT UN 400 V 4 800 V EXIT 0 04 50 s EXIT 1 V 1 V 2 V 0 01 0 02 0 05 0 1 0 2 0 5 1 0 2 0 s 1 of set value or 0 3 UN 1 or 15 ms 35 ms Frequency measuring repetition T 2 99 Cycles 1 Frequency eleme...

Page 45: ...arameters for the fault recorder Function Parameter Adjustment example FR Number of recordings 1 2 x 8 s 3 4 x 4 s 7 8 x 2 s with 50 Hz 1 2 x 6 66 s 3 4 x 3 33 s 7 8 x 1 66 s 60 Hz FR Saving of the re...

Page 46: ...ng relay MRN3 with voltage frequency and vector surge supervision Voltage frequency and df dt supervision 1 2 Rated voltage 100 V 230 V 400 V 1 2 4 Housing 12TE 19 rack Flush mounting A D RS485 Altern...

Page 47: ...tripping delay for under voltage element s 0 04 U pickup value for overvoltage element low set V 110 250 440 tU tripping delay for overvoltage element s 0 04 U pickup value for overvoltage element hi...

Page 48: ...tion Default settings Actual settings Blocking Not blocking Blocking Not blocking Parameter set Set 1 Set 2 Set 1 Set 2 Set 1 Set 2 Set 1 Set 2 U X X U X X U X X U X X f1 X X f2 X X f3 X X X X df dt X...

Page 49: ...Code jumper Low High range for Reset input Low High range for blockage input Default settings Actual settings Default settings Actual settings Low plugged X X High not plugged All settings must be che...

Page 50: ...10 07 55 P O Box D 47884 Kempen Germany Phone 49 0 21 52 145 1 Internet Homepage http www woodward seg com Documentation http doc seg pp com Sales Phone 49 0 21 52 145 635 Telefax 49 0 21 52 145 354...