ERL MIT161, Application And Commissioning Manual

Page 1: ...1 AUGUST 2001 APPLICATION AND COMMISSIONING MANUAL MIT161 RELAY EASUN REYROLLE LIMITED ...

Page 2: ...2 Issue No 2nd Issue Date of Issue 30 08 2001 Department TP CTS ...

Page 3: ...3 MIT161 RELAY SENSITIVE CURRENT PROTECTION PROTECTION HEALTHY MIT 161 STARTER TRIP EASUN REYROLLE INDIA ...

Page 4: ...4 CONTENTS PAGE APPLICATION 5 INSTALLATION 12 COMMISSIONING 18 WIRING DIAGRAM 24 ...

Page 5: ...n distribution systems At the fault position the plastic melts and temporarily reseals the faulty cable for a short time after which the insulation fails again The same phenomenon has occurred in joint boxes where an internal flashover temporarily reseals The behaviour of different types of over current relays under flashing fault condition is compared in Fig 1 The repeating process often caused e...

Page 6: ... SYSTEM EARTH FAULT Distribution Feeder Fault Current magnitude depends upon the amount of fault resistance and it can vary from reasonable value to a very low value MIT161 has two elements which can be set for IDMTL and SEF protection to get complete protection for line ground fault Fig 2 CT Residual Connection Fig 2 shows the CT residual connection for detecting earth faults Y R B MIT 161 ...

Page 7: ...cation Fig 3 CBCT Connection 5 CAPACITOR UNBALANCE CURRENT PROTECTION MVT161 can be used for unbalanced current protection of double star delta and single phase capacitor banks INSTALLATION Fig 4 Double Star Capacitor Bank Neutral Unbalance Protection MIT 161 Y R B MIT 161 ...

Page 8: ...ance protection 3 MIT 161 relays have to be used 6 TECHNICAL INFORMATION 6 1 Rating 1 Amp 5Amps 6 2 Frequency 50 Hz 6 3 Auxiliary Supply Nominal Voltage Voltage Range 24 30 48 110V DC 18 135 V DC 48 110 220 V DC or 110V AC 43 280V DC 6 4 Settings Earth fault element 0 5 to 25 in steps of 0 5 Low set element 0 5 to 25 in steps of 0 5 Time Multiplier 0 025 to 1 0 in steps of 0 025 Reset Time 0 to 60...

Page 9: ... can be calculated as follows K x TM T I IS α 1 Where I Fault current IS Setting current TM Time Multiplier Setting SI3 K 0 14 α 0 02 SI1 K 0 0613 α 0 02 VI K 13 5 α 1 0 EI K 80 0 α 2 0 LT1 K 120 0 α 1 0 6 6 Accuracy Starter 104 of setting 4 Reset 94 of setting Repeatability 1 IDMTL Operate Time 5 or 35 m sec DTL Operate Time 1 or 35 m sec 6 7 Output Contacts 6 7 1 THE RELAY HAS 5 OUTPUT RELAYS 1 ...

Page 10: ... to 55 C Storage Range 25 C to 70 C 7 2 Humidity IEC 60068 2 3 4 days at 40 C and 93 RH 7 3 Transient Over voltage IEC 60255 5 5KV 1 2 50µs 0 5J between all terminals and Earth or between any two terminals without damage or flashover 7 4 Insulation IEC 60255 5 Variation 2 0KV rms for 1 min between all terminals and earth 2 0KV rms for 1 min between Independent circuits 1 0KV rms for 1 min across n...

Page 11: ...dio Frequency Interference IEC 60255 22 3 Class III Variation 20MHz to 1000MHz 10 V m 3 7 8 Fast Transient IEC 60255 22 4 Class IV Variation 4KV 5 50nS 2 5KHZ repetitive 5 7 9 Vibration Sinusoidal IEC 60255 21 1 Class 1 7 10 Shock and Bump IEC 60255 21 2 Class 1 8 CUTOUT DETAILS 151 x 151mm 2 3 Vedette draw out case ...

Page 12: ...e is at the same potential as the relay by touching the case The relay must not be handled by any of the relay terminals at the rear of the chassis Ensure that anyone else handling the relay is at the same potential As there are no user serviceable parts and adjustable user settings inside the relay there should be no requirement to remove any modules from the chassis If any modules are removed or...

Page 13: ...1 11A For 5A Terminal No of TB Ferrule No of CT wire Black 11 11B Following are the steps to change the current rating of the relay from 1A to 5A 1 Identify 11th terminal from number strip on bottom terminal block at the rear of the chassis 2 The black colour wire 11A is inserted to 11th terminal of TB 3 First carefully lift the PVC boot of the wire by means of a tool like nose Plier to expose ter...

Page 14: ...ectively 2 Green LED Protection healthy indication 3 Yellow LED STARTER Starter indication 4 Red LED TRIP Trip indication 5 Red LED in Key Sub Menu 6 Key Up scrolling 7 Key Down scrolling 8 Key Enter Reset Cancel To check Version 5 3 How to operate HMI Remove the front cover by unscrewing the four knurling screws Apply DC supply Terminals 22 24 and 23 are for positive negative and earth respective...

Page 15: ... Pressing key repeatedly the Sub menu will scroll down in the following order on the display Characteristics 2 is in OFF Standard Inverse 3 Seconds characteristics Standard Inverse 1 3 Seconds Very Inverse Extremely Inverse Long Time Inverse Definite Time Lag By pressing or key choose the desired characteristic and press key Now the Submenu LED goes OFF and the Main menu appears on the LED display...

Page 16: ...e again press the key Sub menu LED goes OFF to return to the main menu 6 3 2 LOW SET a For Inverse Characteristics Pressing key repeatedly get Main menu represents Low set Time Multiplier setting has been set to 1 000 press key Submenu LED On to get the Sub menu Pressing the or key changes the time setting by 0 025 increment or decrement Upon selecting the desired setting once again press the key ...

Page 17: ...in menu press or key 8 TO CANCEL SETTING WHILE CHANGING CANCEL While the particular setting is being changed using or key with Submenu LED ON by pressing X key the original setting is restored 9 TRIP INDICATION AND RESETTING OF TRIP INDICATION RESET When the relay operates RED TRIP LED indicates tripping By pressing repeatedly the arrow key you will get all trip indication That is if Earth fault t...

Page 18: ...y testing is started 4 PRECAUTIONS Before testing commences the equipment should be isolated from the current transformers and the CTs to be short circuited in line with the local site procedures The tripping and alarm circuits should also be isolated where practical Also ensure that trip links are removed Ensure that correct DC auxiliary voltage and polarity is applied See the relevant scheme dia...

Page 19: ...ce the current until the LED goes off and record this as the reset level Repeat this test for low set also Check that all the pick up current levels are measured within 104 4 of the applied setting Check that the reset levels are 94 of the setting POLE PICK UP SETTING MEASURED PICK UP PICK UP ERROR MEASURED RESET RESET ERROR E F LOW SET TABLE 1 5 2 2 IDMTL DTL CHARACTERISTICS This test checks the ...

Page 20: ...0 0 71 LTI 120 00 30 0 13 33 6 32 DTL TABLE 2 USER SETTING 2 x Is 5 x Is 10 x Is 20 x Is Pole Characteristic SI3 SI1 EI VI LTI DTL Delay Error 5 Delay Error 5 Delay Error 5 Delay Error 5 LOWSET TABLE 3 5 2 3 OUTPUT CONTACTS COMBINATION a Starter C O This contact is to be used while testing the pick up and reset value of the relay b Common Trip Alarm for E F and LOW SET 2 N O contacts These contact...

Page 21: ...imary system Using the circuit shown in Fig 7 check the current transformer ratio and CT phase to earth connection Inject a current of sufficient magnitude The secondary current is Is Primary current CT ratio 5 4 Putting Into Service After completing all tests satisfactorily the relay should be put into service as follows Make a final check of the secondary wiring and tightness of all terminal con...

Page 22: ...good quality switch Fig 6 Secondary injection timing test circuit Terminals shown are for 1A rating A TIME INTERVAL METER START STOP 240 V A C SUPPLY ve ve D C SUPPLY E F 11 12 22 24 3 4 23 Double Pole switch ...

Page 23: ...23 Fig 7 Primary Injection Test Circuit for E F Relay Terminals shown are for 1A rating ve ve D C SUPPLY E F A PRIMARY INJECTION TEST SOURCE MIT 161 11 12 22 24 23 I I ...

Page 24: ...block 2 Terminal No 23 Earth is to be connected directly to Earthbar 1 A 1 1 B 1 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 CT SHORTING CONTACT CASE TERMINALS VIEWED FROM REAR Ve Ve Earth Y R B 24 MIT 161 Earth Fault ALARM TRIP EARTH FAULT LOWSET PROTECTION HEALTHY STARTER EARTH AUXILIARY SUPPLY VE VE 1 A 1 1 B 1 23 22 12 11 1 2 3 4 13 14 15 16 17 18 20 21 19 MIT161 WIRING DIAG...