Alstom MCAG 14, Service Manual

Page 1: ...Service Manual Type MCAG 14 34 High Stability Circulating Current Relays ...

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Page 3: ... touching the electronic components printed circuit track or connectors 3 Do not pass the module to any person without first ensuring that you are both at the same electrostatic potential Shaking hands achieves equipotential 4 Place the module on an antistatic surface or on a conducting surface which is at the same potential as yourself 5 Store or transport the module in a conductive bag More info...

Page 4: ...sils 11 2 4 Commissioning preliminaries 11 2 5 Commissioning tests 13 3 MAINTENANCE 14 4 MECHANICAL SETTINGS 15 4 1 General 15 4 2 Contact settings 15 4 3 Mechanical flag settings 15 5 PROBLEM ANALYSIS 15 5 1 Failure to operate 15 5 2 Excessive current taken by relay 16 5 3 Output contacts not changing state 16 6 SPARES 16 7 COMMISSIONING TEST RECORD 21 REPAIR FORM 23 ...

Page 5: ...sub assembly eg power supply Note The term earth used throughout the product documentation is the direct equivalent of the North American term ground Installing Commissioning and Servicing Equipment connections Personnel undertaking installation commissioning or servicing work on this equipment should be aware of the correct working procedures to ensure safety The product documentation should be c...

Page 6: ...oltage produced may be lethal to personnel and could damage insulation External resistors Where external resistors are fitted to relays these may present a risk of electric shock or burns if touched Battery replacement Where internal batteries are fitted they should be replaced with the recommended type and be installed with the correct polarity to avoid possible damage to the equipment Insulation...

Page 7: ...ge hazards Hazardous live voltages may be accessible on the extender card Insertion and withdrawal of heavy current test plugs When using a heavy current test plug CT shorting links must be in place before insertion or removal to avoid potentially lethal voltages Decommissioning and Disposal Decommissioning The auxiliary supply circuit in the relay may include capacitors across the supply or to ea...

Page 8: ...0 A2 1995 Distribution level fixed Category Category III installation Equipment in Overvoltage EN 61010 1 1993 A2 1995 this category is qualification Category III tested at 5kV peak 1 2 50µs 500Ω 0 5J between all supply circuits and earth and also between independent circuits Environment IEC 61010 1 1990 A2 1995 Compliance is demonstrated by Pollution degree 2 reference to generic safety EN 61010 ...

Page 9: ...tions where they are exposed to dust or damp This particularly applies to installations which are being carried out at the same time as constructional work 1 4 If relays are not installed immediately upon receipt they should be stored in a place free from dust and moisture in their original cartons and where de humidifier bags have been included in the packing they should be retained The action of...

Page 10: ...t remain stable IFM Maximum value of primary fault current for internal fault IP Primary current for operation of protection IR Relay operating current N Turns ratio of current transformer n No of current transformers in parallel with relay RCT Secondary resistance of current transformer RL Lead resistance between furthest current transformer and relay connection point RR Relay impedance RST Value...

Page 11: ...aximum secondary internal fault current the metrosil cut off point should not be greater than 1500 volts rms or 2120 volts peak 2 4 Commissioning preliminaries 2 4 1 Inspection Carefully examine the module and case to see that no damage has occurred during transit Check that the relay serial number on the module case and cover are identical and that the model number and rating information are corr...

Page 12: ...the tests subsequently must be replaced 2 4 4 Terminal allocation Terminals of the relay are normally allocated as below but reference should always be made to the relevant diagram a Single pole relays Normally open contacts 1 3 and 2 4 AC current input 27 28 b Triple pole relays Normally open contacts 1 3 and 2 4 The contacts are normally connected in parallel for the three phases but a version o...

Page 13: ...ries of any current transformers Increase the current until the relay just operates Note the current in the relay this can be done using the miniature split plug inserted into the appropriate position of the plug bridge connected to an ammeter Note also the voltage VR at which the relay operates which should correspond to the setting VR of the relay plus stabilising resistor with a tolerance of 10...

Page 14: ... to neutral Where primary injection is not practicable in the case of restricted earth fault protection on a transformer it may be possible to check stability by means of back energising the transformer from a low voltage 415 volt supply as shown in Figure 4 In the case of machine protection similar stability tests must be carried out by injecting into one and out of another current transformer co...

Page 15: ...tacts With the armature closed onto a 0 011 feeler gauge the make contacts should be closed but should be open using a 0 013 feeler gauge Force to just close the make contacts 11 16 grammes 4 3 Mechanical flag settings 4 3 1 Settings for self reset units With the armature closed onto a 0 013 feeler gauge the flag should be free to fall but should not fall using a 0 018 feeler gauge Adjustment is m...

Page 16: ...aned with the burnishing tool supplied in relay tool kits On no account should knives files or abrasive materials be used Check mechanical settings as per Section 4 Section 6 SPARES When ordering spares quote the full relay model number and any component reference numbers or briefly describe the parts required Should the need arise for the equipment to be returned to ALSTOM T D Protection Control ...

Page 17: ...ary injection of relay to check secondary operating current setting voltage and relay operating current V A1 A2 Stabilising resistor if fitted Relay Metrosil if fitted Ammeter in plug bridge circuit A2 Stabilising resistor if fitted Relay Ammeter in plug bridge circuit V Primary injection test set A1 ...

Page 18: ...y check on restricted earth fault scheme by back energising with a low voltage supply A2 Stabilising resistor if fitted Relay Primary injection test set A1 Temporary connection A B C Metrosil if fitted A2 Stabilising resistor if fitted Relay A1 Temporary short circuit A B C LV supply ...

Page 19: ...y current Figure 6 Checking stability of generator differential protection A B C V 87 87 87 Temporary short circuit Generator Isolating links 87 Generator differential relay V Voltmeter A B C 87 87 87 Temporary short circuit Generator Isolating links 87 Generator differential relay A2 Ammeter A2 A2 A2 ...

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Page 21: ...ing voltage ___________________ Relay setting ___________________ Stabilising resistor Shunt resistor ohms ___________________ ohms if fitted ___________________ Type of external Calculated primary Metrosil ___________________ OP current ___________________ Test results 2 5 1 Relay CT shorting switch 2 5 2 Secondary current to operate relay Phase Total current A1 Relay current A2 Voltage A B C 2 5...

Page 22: ...e Primary current A1 Spill current A2 A1 A2 B1 B2 C1 C2 Where more than two sets of current transformers are involved injection should be carried out between set 1 and each other set in turn ______________________________________ _______________________________________ Commissioning Engineer Customer Witness ______________________________________ _______________________________________ Date Date ...

Page 23: ... AC current _____________ Main CT Test set Frequency _____________ 2 Which type of test was being used ____________________________________________ 3 Were all the external components fitted where required Yes No Delete as appropriate 4 List the relay settings being used ____________________________________________________________________________ ____________________________________________________...

Page 24: ..._____________________ ____________________________________________________________________________ 9 Was there any visual damage ____________________________________________________________________________ ____________________________________________________________________________ ____________________________________________________________________________ 10 Any other remarks which may be useful...

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Page 28: ... 1785 223251 Fax 44 0 1785 212232 Email enquiries pcs alstom co uk Internet www gecalsthomgpc co uk 1998 ALSTOM T D Protection Control Ltd Our policy is one of continuous product development and the right is reserved to supply equipment which may vary from that described Publication R8008D Printed in England ...