Service Manual R8061 Type MFVU 21 Under/Over Frequency
Contents
1. lt fl gt T lt T f2 V Set Reset Reset Set 1228 Reset fl gt f2 C4 H 62 RL1 1 RL1 2 RL2 1 RL2 2 Notes a Short terminals break before b b e gt Long terminals Figure 1 Typical block diagram AC relay diagram no 10 MFVU21 501 g Boy Case earth 29 Module terminal block viewed from rear Notes a eg N 1 N N N o 1 Test T lt T T lt T lt fl lt f2 Set Reset oe Reset Set gt fl gt f2 H c f2 RL1 1 RLI 2 RL2 1 RL2 2 a gt Short terminals break before b b 3 Long terminals A Auxiliary supply unit only required for AC and DC supplies for Vx 125V and for use with 110V DC relay Figure 2 Typical block diagram DC relay diagram no 10 MFVU21 502 500 to2. and f2 LEDS light and that all output contacts operate See Figure 1 Release the test button and check that pressing the reset button causes the LEDS to go off 3 2 3 2 Checks using the supply to be monitored With independent elements ie PU DO set 1 1 connect the accurate frequency meter to monitor the supply and a double pole switch to connect one pole of the supply to the relay and the other pole of the switch to start the time interval meter Measure the supply frequency to the nearest O 1Hz then calculate the period t for a frequency 0 1Hz below and above the supply frequency At frequencies greater than 100Hz use a difference greater than 0 1Hz say 0 5Hz at 400Hz Set tl and t2 to give a frequency 0 1Hz below the supply frequency set lt fl and lt f2 on the option switches and check that no operation is obtained when the supply frequency is switched to the relay Check that with gt fl and gt f2 set operation is obtained Set t1 and t2 to give a frequency 0 1Hz above the supply frequency Check that with gt fl and gt f2 set on the option switches that no operation is obtained when the supply is switched to the relay Check that with lt fl and lt f2 set operation is obtained on switching on the supply Set the option switches to their required operating positions Also set the required times for t1 and t2 Timing checks can now be done using the necessary t1 and Page 14 3 2 4 settings to give operation when the supp
3. SAFETY SECTION This Safety Section should be read before commencing any work on the equipment Health and safety The information in the Safety Section of the product documentation is intended to ensure that products are properly installed and handled in order to maintain them in a safe condition It is assumed that everyone who will be associated with the equipment will be familiar with the contents of the Safety Section Explanation of symbols and labels The meaning of symbols and labels which may be used on the equipment or in the product documentation is given below A Caution refer to product documentation Caution risk of electric shock CC Protective safety earth terminal gt Functional earth terminal Note this symbol may also be used for a protective safety earth terminal if that terminal is part of a terminal block or 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 N 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 consulted before installing commissioning or servicing the equipment Terminals exposed during installation commissioning and maintenance may present a hazardous voltage unl
4. are used tl must be less than t2 The output relay RLI is controlled by the setting of fl and LI Whatever mode is selected there are two other switches which enable the f1 and or f2 circuitry to be made inoperative This would only normally be done if changing settings with the relay live on the system otherwise they should be set to fl on and f2 on The light emitting diode operation indicators are lit when the corresponding output relays pick up and are latched until the input is back to normal and the reset button pressed In the PU DO f2 fl mode the f2 led can be reset before RL2 resets The test button causes an output to be given from the appropriate relay and indication when under frequency operation is selected It should be noted that the auxiliary supply which may be either ac or dc is brought in on case terminals 17 and 18 and for supplies greater than 125V nominal an external regulating device is required Page 11 Section 2 INSTALLATION 2 1 2 2 2 3 2 4 General Protective relays although generally of robust construction require careful treatment prior to installation and a wise selection of site By observing a few simple rules the possibility of premature failure is eliminated and a high degree of performance can be expected The relays are either despatched individually or as part of a panel rack mounted assembly in cartons specifically designed to protect them from damage Relays should be exami
5. elements may expose hazardous live parts such as relay contacts Insertion and withdrawal of extender cards When using an extender card this should not be inserted or withdrawn from the equipment whilst it is energised This is to avoid possible shock or damage 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 earth To avoid electric shock or energy hazards after completely isolating the supplies to the relay both poles of any dc supply the capacitors should be safely discharged via the external terminals prior to decommissioning Disposal It is recommended that incineration and disposal to water courses is avoided The product should be disposed of in a safe manner Any products containing batteries should have them removed before disposal taking precautions to avoid short circuits Particular regulations within the country of operation may apply to the disposal of lithium batteries Page 9 Technical Specifications Protective fuse rating The recommended maximum rating of the external protective fuse for this equipment is 16A Red Spot type or equivalent unless otherwise sta
6. set DC volts Battery Power supply 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 5 What did you expect to happen continued overleaf Page 23 6 What did happen 7 When did the fault occur Instant Yes No Intermittent Yes No Time delayed Yes No Delete as appropriate By how long 8 What indications if any did the relay show 9 Was there any visual damage 10 Any other remarks which may be useful Signature Title Name in capitals Company name Page 24 Page 25 ALSTOM ALSTOM T amp D Protection amp Control Ltd St Leonards Works Stafford ST17 ALX England Tel 44 0 1785 223251 Fax 44 0 1785 212232 Email pcs enquiries tde alstom com Internet www alstom com 1999 ALSTOM T amp D Protection amp 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 R8061C Printed in England
7. terminals 1 minimum voltage 400 required 20V 300 C gt 5 C 200 input to terminals 28 amp 27 minimum voltage required 10V 100 10 20 30 40 50 60 Frequency Hz Figure 3 Maximum permissible variation of input voltage with frequency Page 19 Y The sum of numbers by switches to the left Indicate switches set to the left by Th 0 0 sec h bp 0 0 56C T2 gt f lt fl N gt f2 I2 O fi ON OFF V 2 ON OFF PU DO 1 1 f2 fl X 0 0 05 0 our 0 1 0 02 0 0 2 0 02 0 0 2 0 0 5 0 0 tl 0 1 O t2 0 1 gt 9 0 2 o 0 1 2 sec 2 0 2 0 sec i 5 0 5 Deren 10 0 10 0 2026 RESET TEST ALSTOM Figure 4 Chart of in service settings Page 20 Section 6 COMMISIONING TEST RECORD Under Over frequency relay type MFVU 21 Station Circuit Model no Serial no Auxiliary supply Vx V AC DC Visual inspection Insulation tests Auxiliary supply at terminals 17 and 18 Self test facility checks 3 2 3 Checks using supply frequency only Measured supply frequency Hz Setting for t1 and t2 below supply frequency Setting for tl and L2 above supply frequency Correct operation for tl and t2 giving a frequency below supply frequency Correct operation for t1 a
8. 13 3 1 5 Insulation tests 13 3 1 6 Test block type MMLG 13 3 2 Commissioning tests 14 3 2 1 Equipment required 14 3 2 2 Auxiliary supply 14 3 2 3 Commissioning procedure when only the supply frequency is available 14 3 2 3 1 Check using self test facility 14 3 2 3 2 Checks using the supply to be monitored 14 3 2 4 Commissioning procedure if an accurate variable frequency source is available 15 3 2 4 1 Check using the relay self test facility 15 3 2 4 2 Put the required setting on t1 and t2 15 3 2 4 3 IFPU DO is set to 1 1 and lt f is set on a particular element 15 3 2 4 4 IFPU DO is set to 1 1 and gt f is set on a particular element 15 3 2 4 5 IF PU DO is set to f2 fl and lt fland lt f2 are set 16 3 2 4 6 IF PU DO is set to f2 fl and gt fland gt f2 are set 16 3 2 4 7 Make sure all necessary results are recorded and the in service setting chart completed on the sheets provided 16 4 MAINTENANCE 16 4 1 Repeat commissioning tests to prove correct operation or for more limited testing operate the test pushbutton having previously isolated the tripping circuits from the relay output 16 55 PROBLEM ANALYSIS 16 Figure 1 Typical block diagram AC relay diagram no 10 MFVU21 501 17 Figure 2 Typical block diagram DC relay diagram no 10 MFVU21 502 18 Figure 3 Maximum permissable variation of input voltage with frequency 19 Figure 4 Chart of in service settings 20 6 COMMISIONING TEST RECORD 21 REPAIR FORM 23 Page 5 Page
9. EX ZEN UN 4 Z VN j ANA ANN N NJ V4 I Service Manual R8061 Type MFVU 21 Under Over Frequency Protection Relay ALSTOM Service Manual R8061 Type MFVU 21 Under Over Frequency Protection Relay HANDLING OF ELECTRONIC EQUIPMENT A person s normal movements can easily generate electrostatic potentials of several thousand volts Discharge of these voltages into semiconductor devices when handling electronic circuits can cause serious damage which often may not be immediately apparent but the reliability of the circuit will have been reduced The electronic circuits of ALSTOM T amp D Protection amp Control Ltd products are immune to the relevant levels of electrostatic discharge when housed in their cases Do not expose them to the risk of damage by withdrawing modules unnecessarily Each module incorporates the highest practicable protection for its semiconductor devices However if it becomes necessary to withdraw a module the following precautions should be taken to preserve the high reliability and long life for which the equipment has been designed and manufactured 1 Before removing a module ensure that you are at the same electrostatic potential as the equipment by touching the case 2 Handle the module by its front plate frame or edges of the printed circuit board Avoid touching the electronic components printed circuit track or connectors 3 Do not pass the module to any person without firs
10. ase to see that no damage has occurred since installation and visually check that any current transformer shorting switches are wired into the correct circuit and are closed with the module withdrawn Check that the relay rating information is correct for the system Wiring Check that the external wiring is correct to the relevant relay diagram or scheme diagram Ensure that the voltage input connections are either phase to phase or phase to neutral The relay diagram number appears inside the case Earthing Ensure that the case earthing connection above the rear terminal block is used to connect the relay to a local earth bar Insulation tests These tests may be done by the main plant contractor at an earlier date The relay and its associated wiring may be insulation tested between all electrically isolated circuits all circuits and earth An electronic or brushless insulation tester should be used giving a dc voltage not exceeding 1000V Accessible terminals of the same circuit should first be strapped together Deliberate circuit earthing links removed for the tests must subsequently be replaced Test block type MMLG If test block type MMLG is provided the connections should be checked to the scheme diagram particularly that the supply connections are to the live side of the test block coloured orange and with terminals allocated with odd numbers 1 3 5 7 etc and also that the dc connection is routed via test b
11. ays 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 and dielectric strength testing Insulation testing may leave capacitors charged up to a hazardous voltage At the end of each part of the test the voltage should be gradually reduced to zero to discharge capacitors before the test leads are disconnected Insertion of modules and pcb cards These must not be inserted into or withdrawn from equipment whilst it is energised since this may result in damage Fibre optic communication Where fibre optic communication devices are fitted these should not be viewed directly Optical power meters should be used to determine the operation or signal level of the device Page 8 gt gt gt Older Products Electrical adjustments Equipments which require direct physical adjustments to their operating mechanism to change current or voltage settings should have the electrical power removed before making the change to avoid any risk of electric shock Mechanical adjustments The electrical power to the relay contacts should be removed before checking any mechanical settings to avoid any risk of electric shock Draw out case relays Removal of the cover on equipment incorporating electromechanical operating
12. by thumbwheel switches which set the time period for one cycle of the frequency for the required setting The usable setting range is from 0 002008 to 0 099995 which correspond to frequencies of 500Hz and 10 001Hz respectively Three terminals 26 27 28 are provided for the voltage input to the frequency monitoring circuits The voltage input connections must be either phase to phase or phase to neutral Two of the three terminals are selected depending on the maximum voltage which can apear at the terminals Figure 3 details the maximum permissible input voltage for each pair of terminals The period of the input voltage is compared with the set period to determine whether the frequency is higher or lower and an output given according to the operating mode This output then starts a time delay circuit with a minimum fixed setting of 0 15 which is added to giving a maximum of 21 15s in steps of 0 05s If the timing circuit input does not reset a hinged armature relay with two change over contacts will operate when the set time has elapsed When the PU DO 1 1 mode is selected both circuits operate independently as described When the PU DO f2 f1 mode is selected an under frequency latching operation is obtained by selecting lt fl and f2 an over frequency latching mode is obtained by selecting gt fl and f2 The output relay RL2 will have its pickup controlled by the f2 t2 setting and the drop off by the fl t1 setting IF the time delays
13. ess the equipment is electrically isolated If there is unlocked access to the rear of the equipment care should be taken by all personnel to avoid electric shock or energy hazards Voltage and current connections should be made using insulated crimp terminations to ensure that terminal block insulation requirements are maintained for safety To ensure that wires are correctly terminated the correct crimp terminal and tool for the wire size should be used Page 7 gt gt gt gt Pe Before energising the equipment it must be earthed using the protective earth terminal or the appropriate termination of the supply plug in the case of plug connected equipment Omitting or disconnecting the equipment earth may cause a safety hazard The recommended minimum earth wire size is 2 5 mm unless otherwise stated in the technical data section of the product documentation Before energising the equipment the following should be checked Voltage rating and polarity CT circuit rating and integrity of connections Protective fuse rating Integrity of earth connection where applicable Equipment operating conditions The equipment should be operated within the specified electrical and environmental limits Current transformer circuits Do not open the secondary circuit of a live CT since the high voltage produced may be lethal to personnel and could damage insulation External resistors Where external resistors are fitted to rel
14. f2 f1 and gt f1 and gt f2 are set The element controlled by fl and t1 can be checked as in Section 3 2 4 4 The element controlled by f2 and t2 can also be checked as in Section 3 2 4 4 except in addition it must be checked that the contact drop off occurs at the frequency set for fl The f2 LED can be reset at about the f2 frequency 3 2 4 7 Make sure all necessary result are recorded and the in service setting chart completed on the sheets provided Section 4 MAINTENANCE Periodic maintenance is not necessary However periodic inspection and test is recommended This should be carried out every 12 months or more often if the relay is operated frequently or is mounted in poor environmental conditions 4 1 Repeat commissioning tests to prove correct operation or for more limited testing operate the test pushbutton having previously isolated the tripping circuits from the relay output Section 5 PROBLEM ANALYSIS Should any problems be experienced with the relay the commissioning tests should be repeated If the relay is found to be faulty it should be returned to ALSTOM T amp D Protection amp Control Ltd for repair and recalibration since there are no user serviceable parts inside Page 16 Z 985g Case earth gt e Module terminal block viewed from rear Test T lt T gt
15. lock terminals 13 and 15 Page 13 3 2 3 2 1 3 2 2 3 2 3 Commissioning tests Equipment required 1 double pole switch 1 electronic time interval meter 1 accurate frequency meter suitable for apply voltage or frequency meter and oscillator capable of giving at least 20V rms at around the supply frequency to be monitored or calibrated variable frequency source giving at least 20V rms 1 multimeter 1 test plug type MMLBO1 if test block type MMLG is fitted Auxiliary supply The auxiliary supply may be either ac or dc Check with the module removed that the appropriate auxiliary supply is available on case terminals 17 if dc and 18 IF a test block type MMLG is fitted auxiliary dc supplies should be routed through it and removal of the cover isolated the dc positive terminal If the test plug type MMLBO1 is to be used it is necessary to link across the appropriate terminals to restore the auxiliary supply to the relay The voltage should be checked before connection to the relay If the auxiliary supply is greater than a nominal 125V ac or dc then an external auxiliary supply unit is necessary and the relay will always be a dc type Commissioning procedure when only the supply frequency is available 3 2 3 1 Check using self test facility Set the option switches to fH lt f2 fl on f2 on PU DO 1 1 tl and t2 to minimum time Connect auxiliary supply to the relay press the test button and check that both the fl
16. ly is switched to the relay Use one pole of the double pole switch to start the electronic timer in the appropriate mode and stop it with the required relay contact It may be thought desirable to check the minimum and maximum time settings available before doing the check at the actual required setting Take the average of five timing shots Times should be within 3 or 50ms whichever is the greater Put the required settings on t1 and t2 and make sure the result sheets and setting chart are completed Commissioning procedure if an accurate variable frequency source is available 3 2 4 1 Check using the relay self test facility This can be done as described in Section 2 3 3 1 3 2 4 2 Put the required setting on t1 and t2 Set the options required and initially set t1 and t2 to their minimum 3 2 4 3 IF PU DO is set to 1 1 and f is set on a particular element The variable frequency supply should be connected to the appropriate relay terminals via one pole of the two pole switch The voltage is not critical except at low frequencies when the input transformer will saturate at a much lower value If the supply is only a low voltage it may be necessary to connect to the more sensitive input if it is not already connected The figure giving the maximum input voltage for given input terminals at all frequencies should also be referred to See Figure 3 Set the supply frequency just above the set frequency switch it on to the relay a
17. nd slowly lower the frequency until operation is obtained Note that with no time delay set output relay contact chatter may be heard at the operation boundary The measured frequency should show very close agreement with the set frequency taking into account the allowable error in the frequency meter or calibrated source The required times should now be set on t1 and or t2 and the supply frequency set to say 1Hz below the relay set frequency The other pole of the double pole switch should be connected to start the time interval meter and the appropriate relay contact to stop it If it is thought necessary a check on the minimum and maximum time settings could be done first Take the average of five timing shots The time obtained should be within 3 or 50ms whichever is the greater 3 2 4 4 IF PU DO is set to 1 1 and gt f is set on a particular element Proceed as in Section 3 2 4 3 but initially set the supply frequency below the setting and increase it to determine the setting For timing tests set the frequency above the setting 3 2 4 5 If PU DO is set to f2 fl and f1 and lt f2 are set The element controlled by fl and t1 can be checked as in Section 3 2 4 3 The element controlled by t2 and t2 can also be checked as in Section 3 2 4 3 except in addition it must be checked that the contact drop off occurs at the frequency set for fl The f2 LED can be reset at about the f2 frequency Page 15 3 2 4 6 IF PU DO is set to
18. nd t2 giving a frequency above supply frequency Timing tests tl set to 0 15 average time S tl set to 21 15s average time S LI set to S average time S t2 set to 0 15 average time s t2 set to 21 15s average time S t2 set to S average time S tl setting S t2 setting S Chart of in service settings completed 3 2 4 Checks using an accurate variable frequency source Required fl Hz Settl s Measured fl Hz Required f2 Hz Settl s Measured f2 Hz Page 21 Timing tests tl setto 0 1s average time tl set to 21 15s average time tl set to S average time t2 set to 0 15 average time t2 set to 21 15s average time t2 set to EL u average time If PU DO is set to f2 f1 Frequency at which RL2 resets Chart of in service settings completed Commissioning Engineer Customer Witness Company Company Date Date Page 22 REPAIR FORM Please complete this form and return it to ALSTOM T amp D Protection amp Control Ltd with the equipment to be repaired This form may also be used in the case of application queries ALSTOM T amp D Protection amp Control Ltd St Leonards Works Stafford ST17 ALX England For After Sales Service Department Customer Ref Model No GECA Contract Ref Serial No Date 1 What parameters were in use at the time the fault occurred AC volts Main VT Test
19. ned immediately they are received to ensure that no damage has been sustained in transit If damage due to rough handling is evident a claim should be made to the transport company concerned immediately and ALSTOM PROTECTION amp CONTROL Ltd should be promptly notified Relays which are supplied unmounted and not intended for immediate installation should be returned to their protective polythene bags Unpacking Care must be taken when unpacking and installing the relays so that none of the parts are damaged or their settings altered and must only be handled by skilled persons Relays should be examined for any wedges clamps or rubber bands necessary to secure moving parts to prevent damage during transit and these should be removed after installation and before commissioning Relays which have been removed from their cases should not be left in situations where they are exposed to dust or damp This particularly applies to installations which are being carried out at the same time as construction work Storage 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 the de humidifier crystals will be impaired if the bag has been exposed to ambient conditions and may be restored by gently heating the bag for about an hour prior to replacing it in the car
20. t 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 information on safe working procedures for all electronic equipment can be found in BS5783 and IEC 60147 0F IF you are making measurements on the internal electronic circuitry of an equipment in service it is preferable that you are earthed to the case with a conductive wrist strap Wrist straps should have a resistance to ground between 500k 10M ohms If a wrist strap is not available you should maintain regular contact with the case to prevent the build up of static Instrumentation which may be used for making measurements should be earthed to the case whenever possible ALSTOM T amp D Protection amp Control Ltd strongly recommends that detailed investigations on the electronic circuitry or modification work should be carried out in a Special Handling Area such as described in BS5783 or IEC 60147 OF ALSTOM Page 4 CONTENTS SAFETY SECTION 7 l DESCRIPTION 11 1 1 Applications 11 1 2 Brief description 11 2 INSTALLATION 12 2 1 General 12 2 2 Unpacking 12 2 3 Storage 12 2 4 Relay Mounting 12 3 COMMISSIONING 13 3 1 Commissioning preliminaries 13 3 1 1 Electrostatic discharges ESD 13 3 1 2 Inspection 13 3 1 3 Wiring 13 3 1 4 Earthing
21. ted in the technical data section of the product documentation Insulation class Installation Category Overvoltage Environment Product safety CC IC 61010 I 1990 A2 Class EN 61010 1 1993 A2 Class IEC 61010 1 1990 A2 Category Ill EN 61010 1 1993 A2 Category Ill IEC 61010 1 1990 A2 Pollution degree 2 EN 61010 1 1993 A2 Pollution degree 2 73 23 EEC EN 61010 1 1993 A2 EN 60950 1992 A11 Page 10 1995 1995 1993 1993 1993 1995 1995 This equipment requires a protective safety earth connection to ensure user safety Distribution level fixed installation Equipment in this category is qualification tested at 5kV peak 1 2 50ys 500y 0 5J between all supply circuits and earth and also between independent circuits Compliance is demonstrated by reference to generic safety standards Compliance with the European Commission Low Voltage Directive Compliance is demonstrated 1997 by reference to generic safety standards Section 1 DESCRIPTION 1 2 Applications The relay is suitable for any application where definite time under or over frequency protection is required Also several relays may be used in load shedding and reconnection applications Brief description The relay has two independent frequency monitoring circuits which can be set to give outputs for either under f and over f gt frequency The frequency settings are controlled
22. ton Dust which collects on a carton may on subsequent unpacking find its way into the relay in damp conditions the carton and packing may become impregnated with moisture and the de humidifying agent will lose its efficiency The storage temperature range is 25 C to 70 C Relay Mounting The installation should be clean dry and reasonably free from dust and excessive vibration The site should preferably be well illuminated to facilitate inspection An outline diagram is normally supplied showing panel cut outs and hole centres For individually mounted relays these dimensions will also be found in publication R6061 Publication R7012 Parts Catalogue and Assembly Instructions will be useful when individual relays are to be assembled as a composite rack or panel mounted assembly Page 12 Publication R6001 is a leaflet on the modular integrated drawout system of protective relay Publication R6014 is a list of recommended suppliers for the pre insulated connectors Section 3 COMMISSIONING 3 1 3 1 1 3 1 2 3 1 5 Commissioning preliminaries Electrostatic discharges ESD The relay uses components which are sensitive to electrostatic discharges When handling the module care should be taken to avoid contact with components and electrical connections When removed from the case for storage the module should be placed in an electrically conducting anti static bag Inspection Carefully examine the module and c
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