IA110_88_EN_1089-500_On-Load_Tap-Changer_Type_M_∆ - Kopie.pdf

ON-LOAD TAP CHANGER TYPEM A Inspe ction i n s t r u c t i o n s  MASCHINENFABRIK...

ON-LOAD TAP CHANGER TYPEM A Inspe ction i n s t r u c t i o n s  MASCHINENFABRIK MIR Ferialsex IA 110/88 en - 1089/500 Maschinenfabrik Reinhausen GmbH Printed in Germany Postfach 12 03 60 D-8400 Regensburg 12 Telefon (09 41) 4 40-0 Telefax (09 41) 4 42 03 Telex 6 5 881 ON-LOAD TAP CHANGER TYPE M A Inspection Instructions No. 110/88 (additional Inspection Instructions No. 38 z/87 for on-load tap changer type M) Contents 1. General Please note: 1.1 Operational principle of the on-load t a p changer 1.2 Designation of the o n l o a d tap changer models 1.3 Two-column design of t h e on-oad t a p changer t y p e M A Please refer to our Inspection 1.4 Inspection intervals Instructions No. 38z for 1.56 Summary of inspection work important inspection work on diverter switch unit of Preparation..........c iii iii ie ii een veearnenn column 2 (pole V) 2.1 Tools and equipment 2.2 Safety precautions 2.3 Operating position when withdrawing t h e diverter switch unit. Withdrawing the diverter switchunit........................ Cleaning the oil compartment, the tap changer oil conservator and the d i v e r t e r s w i t c h u n i t.........cc irri rrianss. Inspection of the two-pole diverter switch unit (poles W and U}, laminated paperdesign............. teresa 56.1 Withdrawal position 5.2 Measuring the transition resistors 5.3 Separating the diverter switches (pole W from pole U) 5.4 Cleaning the insulating drive shafts 5.5 Work on diverter switch pole W 5.51 Setting the mid-position 5.562 Detaching the contact shell 5,53 Removing t h e a r c c h u t e s 5.54 Cleaning the diverter switch 5.55 Determination of contact wear 5.56 Reattaching the contact shell Contents Page 5.57 Detaching and reattaching the transition resistor shells 5.58 Locking-in the diverter switch 5.6 Work on diverter switch pole U 5.61 Setting the mid-position 5.62 Other tasks — detaching the contact shells - removing the arc chutes = cleaning the diverter switch - cleaning the insulating shaft — determining the contact wear - reattaching t h e contact shell g transition resistor shells — detaching and r e a t t a c h i nthe —locking-in the diverter switch 5.7 Reassembling the diverter switch unit inspection of the two-pole diverter switch (poles W and U) GFRP type ( a s f r o m 1 9 8 8 )...............cu. cvearvasianiis 22 6.1 Withdrawal position 6.2 Measuring the transition resistors 6.3 Separating the diverter switch (pole W from pole U} 6.4 Removing the upper supporting cylinder 6.5 Checks on diverter switch poles W and U 6.51 Setting the mid-position 6.52 Detaching the contact shell 6.53 Removing the arc chutes 6.54 Cleaning the diverter switch 6.55 Determination of contact wear 6.56 Reattaching the contact shell 6.57 Detaching and reattaching the transition resistor shells 6.58 Locking-in the diverter switch 6.6 Reassembling the diverter switch unit Replacement of diverter switch arcing contacts and contactbraids..........c ivi iii aennn ceaserarenss 28 7.1 Diverter switch arcing contacts 7.2 Contact braids Reinstalling the diverter switch unit................... cireess 31 Oil filling....... I || Otherchecks.....covvvevee UP 1| 10.1 Operational test of tap-change monitoring circuit 10.2 Drive shafts 10.3 Operational tests of motor drive unit and tap changer 10.4 Protective devices 10.6 Voltage regulator 11. Appendix........ PP X 11.1 Coupling of tap changer and motor drive 11.2 Inspection tools 11.3 Lifting device 11.4 Spare parts list 11.5 Parts of the diverter switch, poles W and U 11.6 Adjustment plans 1. GENERAL the preselected tap. During this quick insulation level, tap selector size, and change-over, ohmic resistors are basic circuit diagram. The designation 1.1 Operational principle of the inserted in the circuit to ensure no- incorporates all these characteristics on-oad tap changer (fig. 1) break transfer of the current. and permits easy identification of the tap changer. A tap-change operation is initiated 1.2 Designation of on-load tap by the tap selector preselecting the changer models (fig. 2) The basic circuit diagram code in the desired tap on the transformer tap : model designation identifies: number winding. Every tap changer type is available in of tap selector contacts, number of a number of different models. These operating positions, number of mid- The diverter switch transfers the designs vary according to: number of positions and type of change-over current from the tap in service to poles, max. rated through-current, selector. = | Motor drive unit Tap selector Diverter switch Time in seconds Circuit diagram A , B -— maincontacts a,b — main switching contacts Ray b a l , b 1 — transition contacts Af af ai bi Contact movement a b al bl Fig. 1 Tap-change operational sequence Example in fig. 2: On-load tap changer type M A On-load tap changer 3-pole, max. rated through-current M Ill 500A — 110 / C — 10 19 1 W 500 A, insulation to ground and bet- ween the phases for voltage class 110 kV, tap selector size C , basic circuit diagram 10 191W, meaning: Type 10 contacts, 19 operating positions, ba Basic connection with one mid-position and the change- Number diagram over selector used as reversing of poles —— Tapselectorsize switch. Max. rated through-current inamperes and 1.3 Two-column design of on-doad additional indi- cation of model L T Isolation level to ground, tap changer type MA Voltage class I nkifovolts The on-load tap changer has two co- lumns (see f i g.3).Column 1 consists of a two-pole diverter switch (pole W Basic connection dlagram ‘and U) and a single-pole tap selector. 10 19 1 w Column 2 consists of a single-pole diverter switch (pole V) and a two- pole tap selector. Diverter switch pole W of column 1 Tap selector pitch Mid-position{s) Change-over selector is connected to the tap selector of column 2 by connecting leads. | [+] | | 1 10 Max.number of a [ RR Contacts should be replaced if this a, value is reached or expected to be CLRIXN reached before the next inspection. Q b) the mechanical tap-change RA PRR RR operation sequence (see section R 1.1) of main contacts (A, B), main switching contacts (a, b), XXXQ RX 3 transition contacts (a1, b1). x 2 RR , T T T Sr S. 0.0.4 C) SUS S p e I RRERR LER If the difference between main switch- ing and transition contacts could be- Yo 0 a \EAN come greater than certain given limits, the correct mechanical switching se- TRRREZX "638, XX] e RS Tene, 2Tee quence of the diverter switch is no %REARS *. 3$TRERXS & £20050 2 longer ensured. a%a% Vo)2X % 6250 22 & o,oS 2 3 7%x3 he; os Unfavourable operating conditions can cause increased contact wear on transition contacts. The max. permissible difference of contact layer thickness between main switching and transition contacts is 2.5... 2.6 mm. [f this difference has Fig. 39 been reached or is expected to be reached before the next inspection, Max. permissible contact wear of the contacts shall be replaced or stationary and movable contacts matched to the other contacts by X — x =4mm, interchanging or milling. x : 8:03mm y4mm new condition x = 8 +£ 0.3 mm Measure the thickness of the contact layers on the stationary and movable main switching and transition con- tacts by vernier gauge and note. Determine the contact wear by com- paring the difference between new contact and measured value. 16 5.566 Reattaching the contact shell Reattach the contact shell in reverse order to removal. The diverter switch is in the mid-position (see section 5.51). Pry in a chucking wedge bet- ween epoxy segment and contact carrier to hold back the movable con- tact system of the diverter switch (see appendix, section 11.2). This compensates the pressure of the movable contact system (fig. 40, 41) and makes attachment of the contact shell easier. Refit the arc chutes. Make sure that arc chutes are properly seated. Fixing the contact shell: 8 screws M6 x 20 (w.s. 10), m a x. torque 5 N m , l o c k tabs, 2 screws M8 x 25 (w.s. 13), max. torque 22 Nm (fig. 42). Each screw has 1 washer and 1 dished washer, lock tab. Do not yet screw in the bolts for the resistor leads. After tightening the screws upwardly remove the chucking wedge (fig. 43). | Ro J Ae [2 2] 5.57 Detaching and reattaching the “RN rd [ transition resistor shells Loosen 1 hexagon socket screw M6 x 10 (w.s. 4) for the potential connec- tion below the sliding contact (fig. 44). Unlock and loosen 2 screws M8 x 25 (w.s. 13), (fig. 45). Each screw has: 1 washer and 1 dished washer, note assembly position. Unlock and loosen 4 screws M6 x 20 (w.s. 10), (fig. 46). Detach and clean the transition resis- tor shell, clean the transition resistor (refer to section 5.54). 17 Reattach the transition resistor shell. Make sure that the resistor leads are well free of the contact shell. Fixation: 4 screws M6 x 20 (w.s. 10), max. torque 5 Nm, lock tabs; 2 screws M8 x 25 (w.s. 13), max. torque 22 Nm, each screw has 1 washer, 1 dished washer, lock tab. Potential connection: 1 hexagon socket screw M6 x 10 (w.s. 4), max. torque 5 Nm, locked by centerpunch. Proceed likewise w i t h t h e other tran- sition resistor shell. Screw in the bolts of the resistor connections on the contact shell: 6 hexagon socket screws M6 x 10 (w.s. 4), max. torque 5 Nm, locked by center-punch (fig. 47). 5.58 Locking-in the diverter switch After assembly, lock-in the spring energy accumulator in any position of the diverter switch. Fig. 49 Fig. 50 P a w ! locked-in Insert a screw driver between cocking and wind-up sledge. Turn the drive shaft with the operating key until the paw! locks in (fig. 49, 50). Operate the diverter switch several times to check its mechanical function. 5.6 Work on diverter switch pole U (fig- 51) 5.61 Setting the mid-position Unlock the spring energy accumulator as described in 5.51. Turn the eccen- tric using the flat side of the operating key until the spring energy accumula- tor is in the mid-position (fig. 52, 53). 18 5.62 Proceed as described for diverter switch pole W — Detachingthe contact shell (fig. 54, 55, 56) — Removing the arc chutes (fig. 57) — Cleaning the diverter switch — Determining the contact wear — Reattaching the contact shell (fig. 58, 59, 60, 61) 19 — Detachingand reattaching the transition resistor shells (fig. 62, 63, 64) — Locking-inthe diverter switch (fig. 65) Operate the diverter switch several times to check its mechanical function. 5.7 Reassembling the diverter switch unit Get both diverter switches into the same position before assembling (pole W: fig. 66, pole U : fig. 67). 20 Attach the lower insulating shaft to diverter switch pole U (fig. 68). The upper groove must point in direction of eccentric. Lift diverter switch pole W over pole U and engage the lower insulating shaft. Screw-connect the two diverter swit- ches, i. e. the 3 laminated paper shells of pole W with the spring energy accumulator housing of pole U. Attachment: 8 screws M8 x 35 (w.s. 13) with lock nuts, max. torque 11 Nm, each screw has 1 washer, 3 dished washers. Insert the spacers as shown in fig. 69. Perform a few trial operations. Set the diverter switch to the withdrawal posi- tion (see section 5.1). The diverter switch unit is now ready for installa- tion (fig. 70). Fig. 69 Attachment of the laminated paper shells of diverter switch pole W Parts: 056 4 5 2 spacer, laminated paper 056 514 l o c k tab 450 090 h e x. head screw M 8 x 2 8 450 388 hex. head screw M8 x 35 451 326 washer 452 357 dished washer 453 978 lock nut M8 70 21 6. INSPECTION OF TWO-POLE DIVERTER SWITCH UNITS (POLE W, U), GFRP TYPE (AS FROM 1988) The diverter switch unit comprises two fully insulated diverter switches, consisting each of a spring energy accumulator, a contact system sector and two transition resistor shells. 6.1 Withdrawal position Carefully note the existing switched position of the diverter switch (= with- drawal position). Note the position of the release lever of the spring energy accumulator (fig. 71) because i t must be replaced in exactly the same ope- rated condition. 6.2 Measuring the transition resistors (fig. 72) Measure the value of each transition resistor. The values are in the order of 0. 3... 3 0 ohms. Measure at the open side of the diver- 71 ter switch sector between stationary main switching and transition contact above and below. Repeat the measure- ment on the opposite side. Set the di- verter switch to the opposite position by means of the operating key (see appendix, section 11.2). Compare the measured values with the nameplate values. A 10 percent deviation is permissible. Perform a control measurement of the 2 x 100 kiloohms tie-in resistors at pole W as depicted in fig. 72. 0,3...30Q2 0,3...30Q 0,3...30Q 72 22 6.3 Separating the diverter switch (pote W from pole U) Separate the diverter switch unit at the screw connection between lower support cylinder and housing of the spring energy accumulator of pole U. The connection is the same as bet- ween upper support cylinder and pole W (see section 6.4: 8 screws M 8 x 20 with lock nuts and washers). Further inspection is performed step by step on pole W and pole U (fig. 73). 6.4 Removing the upper support cylinder Before starting, dismount the guide plate for the tap-change monitoring circuit (fig. 74). The guide plate i s attached to the cocking slide by 2 stud bolts M5. The support cylinder is screwed to the lugs of the spring energy accumulator housing. Loosen 8 screws M8 x 20 Pole W Pole U (w.s. 13) with lock nuts and washers (fig. 75). 73 Do not drop any parts into the diverter switch. Detach the support cylinder (fig. 76). Remove the insulating shaft (fig. 77). Clean inside and outside of the sup- port cylinder with brush and clean transformer oil, rinse and wipe dry. Clean likewise both insulating drive shafts outside. 6.5 Checks on diverter switch poles Wand U 6.51 Setting the mid-position Set the diverter switch to the mid- position. Unlock the spring energy accumulator and turn the eccentric using the flat end of the operating key until cocking and wind-up sledge of the spring energy accumulator have reached a stable mid-position (fig. 78, 79). 6.52 Detaching the contact shell Loosen 6 hexagon socket screws M8 x 20 (w.s. 4), selfdocking, for resistor connection (fig. 80). Unlock and loosen one screw M8 x 25 (w.s. 13) on the right and the left of the contact shell (fig. 81). Each screw has 1 washer and dished washer. Note correct installation position. Unlock and loosen 8 screws M 6 x 2 0 (w.s. 10), fig. 82. Take off the contact shell (fig. 83). 6.53 Removing the arc chutes Withdraw the arc chutes, On-oad tap changer type M Ill 350 A: see fig. 84. On-load tap changer type M 111500 A and M 111600 A (fig. 85): The two outer arc chutes have split sidewalls and must be refitted in exactly their original position. 24 6.54 Cleaning the diverter switch Thoroughly clean the contact shell, all arc chutes and the movable con- tact system using transformer oil and a brush. Likewise clean the resistor shells which are dismounted later on. It All insulating parts should be cleaned e% x.. x ttt t t TXIXRIXS SS RRBRAR U R S5, o Padelelotetote% I eee 007000 2K E R R with special care. Rinse well with etetetet >SIRS transformer oil and wipe dry. bo , Xs ’ QD S >be! 0, XR RRX RXR oto! X X Xo; 3 Clean the diverter switch between 0 disassembling and reassembling the INT contact shell and transition resistor Szs shells. Se 0. 0LRIERRAI Clean the lower support cylinder on. 0 0 0 ,T O , esSRRRRRS diverter switch pole W inside and o e TILK? X% SN PRR XR? outside. R S ASSNa R R A telelaietel 2n&s ov= XXRL (2055 6.55 Determination of contact wear boftotels; 2; O A R R R RRRRKRX 2 The admissible wear on the diverter switch contacts is determined by two main features: a) the volume of the contact (see ne id fig. 86). The max. admissible con- od « tact wear on an individual contact is4dmm. i! SJ Fig. 86 The contact should be replaced when Sy this value has been reached or is ex- Max. permissible contact wear of pected to be reached before the next 2 J stationary and movable contacts inspection. X = X =4mm, b) the mechanical tap-change x = 8:03mm yt4mm = new condition x = 8 0.3mm operation sequence (see section 1.1) of main contacts (A, B), main switching contacts (a, b), transition contacts (a1, b1). If the difference between main switching and transition contacts The max. permissible difference of Measure the thickness of the contact could become greater than certain contact layer thickness between main layers on the stationary and movable given limits, the correct mechanical switching and transition contacts i s main switching and transition contacts switching sequence of the diverter 2.5... 2.6 mm. If this difference has by vernier gauge and note. Determine switch is no longer ensured. been reached or is expected to be the contact wear by comparing the reached before the next inspection, difference between new contact and Unfavourable operating conditions the contacts shall be replaced or measured value. ’ can cause increased contact wear matched to the other contacts by on transition contacts. interchanging or milling. 25  the contact shell 6.56 Reattaching Reattaching the contacts shell i s done reversely to removal. For ease of installation pry in a chucking wedge (see appendix, section 11.2) between epoxy segment and take-off contact carrier. This holds back the movable contact system of the diverter switch and compensates the contact pressure (fig. 87, 88). Make sure that the arc chutes are seated properly. Fixation of each contact shell: 8 screws M6 x 20 (w.s. 10), max. tor- que 5 Nm, lock tabs; 2 screws M8 x 25 (w.s.13), each with washer and dished washer, lock tab, max. torque 22 Nm (fig. 89). Do not yet insert the screws for the resistor leads. After tightening the screws upwardly remove the chucking wedge (fig. 90). 6.57 Detaching and reattaching the transition resistor shells Loosen 1 hexagon socket screw M6 x 10 (self-locking, w.s. 4) for the potential connection beneath the slide contact (fig. 91). Unlock and loosen 2 screws M8 x 25 (w.s. 13), fig. 92. Each screw has 1 washer and dished washer. Note correct installation position. Unlock and loosen 4 screws M 6 x 2 0 (w.s. 10), fig. 93. Detach transition resistor shell (fig. 94). Clean transition resistor shell and transition resistor (see section 6.54). Reattach transition resistor shell. Take special care not to distort resistor leads. 26 Attachment: 4 screws M6 x 20 (w.s. 10), max. torque 5 Nm, lock tabs. 2 screws M8 x 25 (w.s. 13), max. torque 2 Nm, each screw with 1 washer, 1 dished washer, lock tab. Potential connection: 1 hexagon socket screw M6 x 10 (self-locking, w. S. 4), max. torque 5 Nm. Proceed likewise w i t h the other transition resistor shell. Now attach the screws of the resistor connection on the contact shell: 6 hexagon socket screws (self- locking, w. s. 4), m a x. torque 5 N m Please note: (fig. 95). — Put the diverter switch insulat- ing shaft onto the eccentric. 6.58 Locking-in the diverter switch The shaft key points to the eccentric. After assembly, lock-in the spring energy accumulator in any operating — Put the support cylinder on the position of the diverter switch. spring energy accumulator housing. Ensure alignment of Insert a screwdriver between wind-up triangle marks of support plate and cocking sledge and turn the (fig. 97) with energy accumula- eccentric with the flat end of the tor housing (fig. 98) so that the operating key (fig. 96) until the pawl shaft for the tap-change monitor- locks in. ing device can be inserted into the lower bearing. Operate the diverter switch several times to check its mechancial — Assemble guide plate for drive function. of tap-change monitoring circuit on the cocking slide of spring energy accumulator (fig. 99). 6.6 Reassembling the diverter Attachment: 2 lock nuts M 5 switch unit (w.s. 8), max. torque 5 Nm. Remount support cylinder with support plate (reverse of removal, see section 6.3). Fixing: 8 screws M8 x 20 (w.s. 13), each one with 2 washers and self- locking nuts, max. torque 22 Nm. Diverter switch pole U Put the lower insulating shaft on the eccentric (fig. 100). Set diverter switch pole W to the same position as pole U (fig. 101). Lift pole W over pole U and screw lower support cylinder of pole W to the lugs of spring energy accumulator housing of pole U. Attachment: 8 s c r e w s M 8 x 2 0 (w.s. 13), each one with 2 washers and lock nut, max. torque 22 Nm. Check to make sure that the inner resistor leads of diverter switch pole W (between contact shell and tran- sition resistor shells) have sufficient clearance to the upper grading ring of diverter switch insulating drive shaft. Using the operating k e y , repeatedly switch the diverter switch unit i n both directions. Set to withdrawal position (see sec- tion 6.1), fig. 102. The diverter switch unit is now ready for reinstallation. 7. REPLACEMENT OF DIVERTER SWITCH ARCING CONTACTS AND CONTACT BRAIDS 7.1 Diverter switch arcing contacts The diverter switch has 2main switch- ing contacts (a, b) and 2 transition contacts (a1, b1), each one consisting of a stationary and a movable contact. Stationary contacts Each contact consists o f2 contact (see fig. 103, 104) tips. Replacing the contact tips of the Each contact tip i s fixed by a hexagon stationary and movable contact socket screw M6 x 15 (w.s. 4), max. system is very simple (each contact torque 9 Nm, and secured by a centre tip is fixed by just one screw M6). punch at the groove of the screw Please note: 28 Movable contacts (see fig 105, 106, 107) Attachment of each contact tip by hex- head screw M6 x 16 (w.s.10), 2 dished washers, max. torque 9 Nm, secured by lock tab. Furthermore, please note: On-load tap changer M 11350 A Before dismounting the movable contacts, loosen the contact braids top and bottom (see section 7.2). ATTENTION: Transition contacts (a1, b1) have tungsten-copper contact tips on brass contact holders for a through-current in excess of 200 A. The different contact tips are identi- fied by the following MR part numbers: Contact | < 2 0 0 A | > 200A a,b 051783 | 051783 at, b i 051783 | 017355 Industrial transformers with high switching frequency (i.e. electric furnaces) have special contact tips. For replacement please inquire. On-load tap changers M I I 500 A ,.M.1II 600 A ’ Before dismounting the movable contacts, remove the contact braids on top (see section 7.2). -MR part numbers are: 7.2 Contact braids Replace the contact braids after Contact 500A, 600 A 150,000 operations. This is a pre- The contact braids connect the main cautionary measure independent of a,b 009 859 switching and transition contacts of the replacement of arcing contacts. the movable contact system with the al, bi 009 859 slide contact of the output terminal. The contact braids are fixed to the contact system by means of seli- locking screw connections (fig. 108, 109). 29  Please note: On-load tap changer M 111350 A a al b1 b (fig. 110) 012768 I \ (f | 012768 Contact braids for main switching and | RAL transition contacts are joined at the M6x16 M6x16 M6x28 M6x16 M6X16 output terminal. (, 3) | f, =) Two contact braids each top and 012770 012801 bottom +H 1 Attachment to the output terminal: M 6 x 16 M5x22 M6x16 each by 1 screw M6 x 28 (w.s. 10) ( m— f, 2) with self-locking nut and washer, 012 801 012770 max. torque 9 Nm. H AL M6x16 M5x22 M6x16 Attachment to the main switching contact (double lead) and transition \ | / N contact. 012768 [ [a | — 012768 each by 1 screw M6 x 16 (w.s. 10) i | 110 with self-locking nut and washer, M6x16 M6x16 M6x28 M6x16 M6x16 max. torque 9 Nm. 4 contact braids (in the middle) Attachment to the main switching contact: each screw M6 x 16 (w.s. 10) with Fig. 110 Contact braids for M lll 300 A self-locking nut and washer, max. torque 9 Nm. Attachment to the output terminal: each by 1 screw M5 x 22 (w.s. 8) with self-locking nut and washer, max. torque 5 Nm. a al b1 b On-load tap changer type M lI 500 A , M Ill 600 A (fig. 111) 012481 { M6x1e IO M6x16 Nomi M6x25 | M6x16 M6x16 2 contact braids each for main switch- ing and transition contact (top only) _ The contact braids of main switching Fig. 111 Contact braids for M Ill 500 A, M lil 600 A and its transition contacts are joined at the output terminal. Attachment to the main switching and transition contact: each by 1 screw M6 x 16 (w.s. 10) with self-locking nut and washer, max. torque 9 Nm. Attachment to the output terminal: 1 screw M6 x 25 (w.s. 10) with selfdocking nut and washer, max. torque 9 Nm. 30 8. REINSTALLING THE DIVERTER back in the identical operating po- SWITCH UNIT sition. Remove the tap changer head cover. f) Provisionally couple the second column to the first column. Lift the diverter switch unit over the Make sure that positions coincide open tap changer head. Slowly and and that coupling is symmetrical with care lower down into the oil com- (see section 10.3). partment. Take note of the triangle markings in the tap changer head g) Press the push button of the motor (see section 3). When remounting the drive unit to operate both columns diverter switch unit turn, if necessary, by one step. Dismount the drive the insulating shaft slightly until the shaft between the two columns. coupling engages. h) Return column which i s coupled Ensure alignment of marks on support Units with a stationary oil filter unit: to the motor drive unit into its plate of diverter switch unit and in tap operate the oil filter unit and bleed. original position. After the motor changer head (fig. 112). drive has stopped and the time Fill the oil conservator with new oil up relay has dropped, m a k e sure that Fix the diverter switch unit by screws to its original level. the motor drive unit will not start of the support plate. again when push button is actu- ated. Standard design: 4 screws M8 x 20 (w.s. 13). Special design for bell-type 10. OTHER CHECKS i) Return the coupled column into tank installation: 5 nuts M8 (w.s. 13). the same position as the un- 10.1 Operational test of the tap- coupled column by cranking the Both types secured by spring change monitoring circuit motor drive. Reinstall the drive washers, max. torque 22 Nm. shaft. Make sure of identical po- Check function of tap-change moni- sition and symmetrical coupling Reinstall the position indicating disc toring circuit ( = monitoring equality of (see section 10.3). (put clip on shaft end). positions of diverter switches columns 1 and 2) in conjunction with the motor k) Operate both columns by means Reconnect the leads for tap-change drive. Keep the motor drive unit ready of the motor drive into the adjust- monitoring circuit. Pay attention to for electric operation. ment position of the tap changer. lead colours. Proceed as follows: 10.2 Drive shafts 9. OIL FILLING a) Make sure that motor drive unit and columns 1and 2 are in the Couple the horizontal drive shaft to Fill new oil into the diverter switch oil same operating position. upper gear unit and bevel gear compartment up to the level of the (6 screws M6, w.s. 10, support plate. Put the cover on the b) Provisionally couple the column max. torque 9 Nm, lock tabs). tap changer head making sure that nearest to the bevel gear with the the gasket fits properly; if necessary, motor drive. Make sure that posi- Reattach the horizontal drive shaft replace with a new O-ring. tions coincide and coupling is between the tap changer heads of symmetrical (see section 10.3). columns 1 and 2. The head cover is fixed with 24 bolts M10 (w.s. 17), max. torque 34 Nm, ¢) Move coupled column by one step Check horizontal and vertical drive secured by spring washers. by means of motor drive opera- shafts, especially the coupling points. tion. If necessary, grease coupling bolts Open the stop valve between protec- and O-rings (e.g. with SHELL 6432), tive relay and oil conservator. Vent d) After the motor drive has stopped adjust axial clearance to 3 mm. the tap changer head through the and the time relay has dropped bleeder valve in the tap changer head make sure that the motor drive Check bellows and greasing of ball cover (remove screw cap M 3 0 / w.s. unit will not start again when the joints (only special designs with ball 36 and lift valve tappet by means of a push button is actuated. joints). screwdriver). Vent the suction pipe (screw cap M16 / w.s. 22, bleeder e) Return the coupled column to the Check upper gear unit at tap changer screw M6 with cheese head, max. original position by cranking the head cover and bevel gear (add lubri- torque 2 Nm). motor drive. Both columns are now cating grease if necessary). 31 10.3 Operational tests of motor drive relay should, therefore, include check- Maschinenfabrik Reinhausen GmbH unit and tap changer ing the proper function of the circuit Technischer Service breakers. Check symmetrical coupling of motor Falkensteinstrasse 8 drive to the tap changer. Make sure that the transformer cannot P.0.B. 120360 be energized and its ground connec- D-8400 Regensburg 12 Please note: tions cannot be removed during the Phone (09 41) 4 40-0 The diverter switches of columns 1 test. Furthermore, make sure that the Fax (09 41)4 42 03 and 2 should preferably operate si- fire-extinguishing equipment, if any, Telex 6 5 881 multaneously (admissible difference coupled with the tripping of the pro- Cables: oltc reinhausen i s about 1 turn of the hand crank of the tective relay cannot operate. motor drive). Proceed as follows: 10.5 Voltage regulator (see The follow-up of the motor drive must Operating instructions No. 66 be identical i n both directions (adjust 1. Close the circuit breakers with for voltage regulator MK 20) if necessary, see section 11.1 of isolating switches open and trans- appendix). Perform trial operations former terminals grounded. If the tap changer is controlled by a across the whole tapping range. voltage regulator: 2. Open the hood for access to the Thereby check coincidence of posi- test push-buttons (3 screws M6, Check settings of voltage level, sen- tion indication of tap changer (lap w.S. 10). Press the push-button sitivity (bandwidth) and delay time changer heads of columns 1 and 2) TRANSFORMER OFF. The circuit according to the operating instruc- and motor drive in all operating posi- breakers must open. tions in order to avoid unnecessary tions. tap change operations. 3. With the protective relay in Check the electrical and mechanical TRANSFORMER OFF position, it end position of the motor drive unit must be impossible to close the (see our Operating Instructions No. 40 circuit breakers. This i s to be for motor drive MA 7). checked. 4. Reset the protective relay to the 10.4 Protective devices TRANSFORMER IN SERVICE position and lock the hood (3 10.41Tap-change monitoring circuit screws M6, max. torque 5 Nm). (see section 4) The tap-change monitoring circuit Note: ensures that the motor drive will not In case of a response of the protective continue running when the simulta- relay i t is absolutely necessary to neous operation between columns 1 check the tap changer and trans- and 2 i s disturbed. former. For this purpose withdraw aiso the Please note: diverter switch unit. The motor drive must be sure to stop In addition see Operating Instructions when the tap-change monitoring No. 59 for the protective relay circuit responds.Never operate the RS 2001. motor drive neither electrically nor by cranking, as long as the transformer is Before returning to service, make sure energized. Operation must not be re- that the tap changer and transformer sumed before the cause has been are undamaged. Never reconnect the found and remedied. transformer without prior checking. In case of serious trouble with tap 10.42Protective relay RS 2001 (see changer or motor drive — provided that Operating Instruction No. 59) the repair cannot easily be done on site — and in case of a response of the The transformer must be immediately protective relay or the tap-change switched off by the circuit breakers monitoring circuit please contact the when the protective relay is energized. authorized MR representative, the The operational test of the protective transformer manufacturer or 32 11. APPPENDIX 11.1 Coupling of the tap changer and motor drive unit (see also ® Ss 10 1S 20 25 30 33 Operating Instructions N o.40 for motor drive MA 7 and N o 8 motor drive MA 9). 0 for INARNRRNNNRNRRNNNNNEREGE| | |OPERATION OF DIVERTER SWITCH it is absolutely necessary that t h e tap changer operation 25 20 15 10 i 0 Is finished before the motor drive stops. This i s ensured by setting the time of the diverter switch action ( = on-load t a p changing) at a distinct interval mim TOTO =| before the end of the motor drive action (1.5=—2 sections before the red center mark on the tap change Indication OPERATION OF DIVERTER SWITCH wheel). This red center mark is used as reference when 10 15 20 25 30 33 adjusting. | One t a p change operation corresponds t o one rotation of the indicatjon wheel. The tap change indication wheel i s divided into 33 sections (TIW sections) w i t h one section [ HNNNRNERARENN pitas | 111, c corresponding t o one rotation of the crank. |O P E R A T I O N OF DIVERTER SWITCH The number of sections counted from the beginning of the tap change operation until the red center mark of the indication wheel faces the mark on the inspection window, should be equal in both directions. Minor asymmetry is admissible. ® Symmetrical coupling i s achieved as follows: = When adjusting ensure that the position indication readings of motor drive and tap changer are equal. UNCOUPLE | = Tap changer and motor drive have t o be in the adjustment position. 0 3 = Couple tap changer and motor drive. = Turn crank in one direction until diverter switch action occurs, Count the remaining T W sections until the red center mark of t h e t a p changer indication wheel is visible in the middle of the inspection window. = Repeat this procedure i n the opposite direction. = ff there i s a difference between the numbers of COUPLE | sections counted in both directions, the motor drive must be readjusted in relation to the tap changer by half of this difference of numbers. 5 10 15 20 Examples: (see fig. 1 1 3 ) | a) Tap changer is in operating position 10. Turn crank towards 11 until diverter switch action ] 1 LITT occurs, Count number of TIW sections until red center {OPERATION OF mark appears. DIVERTER SWITCH Result: 7 sections. 25 20 15 10 5S b) Tap changer is in operating position 11. Turn crank towards 10 until diverter switch action occurs. Count number of TIW sections until red center mark appears. Tl 1iNINERNRANENNERENE Result: 1.5 sections. ——OPERATION OF DIVERTER SWITCH Correction value: 1 / 2 ( 7 sections — 1.5 sections) = 2.75 sections, chosen 3 sections. c) Turn crank towards 1 1 until red center mark appears. Fig. 113 Symmetrization of coupling between tap changer and d) Uncouple vertical drive shaft. motor drive e) Proceed i n the same direction (towards 1 2 ) b y 3 TIW sections. oT Counting TIW sections after diverter switch action in both directions [ » f) Couple again. Cranking in the direction of the bigger amount of TiW sections +0 ao g) Proceed in the same direction (as with e ) until Uncoupling diverter switch action occurs. Count number of TIW Cranking on by correction value sections until red center mark appears, Result: 4 sections. Coupling | Completing operation, checking number of sections To h) Check in the opposite direction. Result: 4.5 sections. Checking in the opposite direction 33 11.2 Inspection tools Tools for bolts & nuts for installation and inspection.............. Special tools for the inspection «mu ss 2s nEEEEEASeEEEAEFPES en Ean i ; D tem | No. Designation Fig. | DIN | ‘Wrencheize 1 1 Double-ended o p e n - j a w w r e n c h A 895 8x10 2 1 Ring & open-jaw wrench Cc [3113 10 3 1 Double-ended open-jaw wrench A 895 13x17 4 1 Double-ended socket wrench B 896 13x17 5 1 Double-ended open-jaw wrench A 895 17x19 6 1 Double-ended open-jaw wrench A 895 22x24 7 1 Hexagon socket screw key D 911 4 8 1 Hexagon socket screw key D 911 5 9 1 Hexagon socket screw key D 211 8 MRE On-load tap changer type M N 2095.2 en Tools for bolts & nuts for installation and inspection 890 478: 2E 34  WRENCH FOR ENERGY heed ACCUMULATOR 088 538 20 CHUCKING WEDGE 560 131 MASCHINENFABRIK MERE" REINHAUSEN On-load tap changer type M Special tools for the inspection N 2096.2 e n 890 479 : 2E 35 11.3 Lifting device To be mounted on the tap changer head [IE | To be mounted on the tank cover PEER B I E SE S R CT A SI BE) LL 2 ILL SSS ELE LS 2 LLL SSL Zz ES DIVERTERSWITCH | TURNED UNIT SWING B O O _ M| THROUGH 15° RANGE 3 6 0 ° § ] SUPPORTING FLANGE ia —_— SN ! TAP CHANGER HEAD. IoC) IML TRANSFORMER — ree ee : COVER V | Weight approx. 80 kg MASCHINENFABRIK On-load tap changer type M A N 2607.3 en MRE" Lifting device to be attached to the tap changer head 893725: 3E 36  Li zs L l L. lei le Mitkl LLL Aid lk a PR AEE SN / a f mv a v — (] ] 8 —| —TURNED nr SVT | THROUGH 15° [ SWING BOOM | | | RANGE 360° | | Vi 3 \ 1 1) J | | § 1 < >1.~ 1. 1 M15 & TAP CHANGER | HEAD = TRANSFORMER ~ | [ | 7 COVER ro] THREAD M16 /ST50 BUTT- WELDED TO TRANSFORMER COVER PLEASE NOTE: BOLTS, NUTS AND WASHER DO NOT FORM PART OF OUR DELIVERY. Weight approx. 70 kg MASCHINENFABRIK On-load tap changer type M A N 2606.3 en MR rewsaisen Lifting device £93 704 36 1 — EE to be mounted on the tank cover. 11.4 Spare parts list General parts, only required i n case of loss or damage. Quantity per unit t Designati MR-No. Use Item esignation ° Mm3soA | mmsooA | mmeooA 11.401 | Screw c a p 070 071 2 2 2 Bleeder valve o f tap changer Valve tappet 070 072 2 2 2 head cover: Circlip 401 034 2 2 2 Washer 456 071 2 2 2 Spring 500 884 2 2 2 O-ring 400 437 2 2 2 11.402 | Bleeder screw 020019 2 2 2 Bleeder screw of suction pipe elbow Gasket 860 151 2 2 2 Screw c a p 047 670 2 2 2 Gasket 806 150 2 2 2 11.403 | Hex.head screw M6x30 455 005 12 12 12 Attachment of drive shaft coupling Hex.nut M6 455 400 12 12 12 (=1set) Lock tab 052 092 8 8 8 M 11.404 | H e x. h e a d s c r e w10x35] 455 029 48 48 48 Attachment of tap changer Lock washer 400002 48 48 48 head cover 11.405 | Ring gasket 860 258 2 2 2 Gasket of tap changer head cover 11.406 | Lock washer 452 649 8 (10) 8 (10) 8 (10) Attachment of support plate Quantity i n ( ) for bell-type tank cover Spare parts for inspection without replacement of arcing contacts. ; ianati MR Quantity per unit u tem Designation. 8 gnatio ° Mm3soA | mmsooA | mmeooA © 11.407 | Hex.nut M8 453 978 24 24 24 Attachment of support bars or (self-locking) support cylinder on energy acumulator housing Hex.nut M5 453 981 4 4 4 Attachment of guide plate on cocking (self-locking) sledge of energy accumulator 11.408 | Lock tab 070 289 24 24 24 Attachment of contact shell of Lock tab 056 514 4 4 4 diverter switches pole W and U 11.409 | Lock tab 070 289 8 8 8 Attachment of transition resistor shell Lock tab 056 514 4 4 4 of diverter switches pole W und U 11.410 | Recess head screw 451 292 14 14 14 Connection of transition resistors and ‘M6 x 10 potential connection o f resistor shell (self locking) of diverter switches pole W and U 38  Spare parts for replacement of diverter switch arcing contacts and contact braids.. Quantity per unit ftem Designation MRNo- | Mmm3soA | mmsooA | MmeooA Use 11.411 | Contact t i p ? 051873 48 - —- Replacement of main switching and Contact tip2) 051873 24 -— -— transition contacts of the diverter Contact tip?) 017 355 24 - - switch Contact t i p 009 859 -_ 48 48 Lock tab 050 773 24 24 24 Dished washer 088 363 48 48 48 11.412 | Double contact braid 012768 12 -— -_ Replacement of contact braids of Double contact braid 012770 6 - - the diverter switch Double contact braid 012 801 6 - -_ Contact braid 012 481 —_ 6 6 Hex.nut M6 453 977 42 16 15 (selflocking) Hex.nut M5 453 981 6 -— —- (self locking) Note: 1) For through-current of < 2 0 0 A 2) For through-current of > 200 A 39 11.5 Parts of the diverter switch, Stationary contact system, laminated papertype......... Caan 894 451 polesw & U Stationary contact system, GFRP type.......... ana fre raaar 896 464 Movable contact system M I I 3 5 0 A...........chvuviiiiannan, 894 452 Movable contact system MIII500 A , MIIGOOA................. 894 453 Spring energy accumulator................ Sees... 894 454 Part-No. Designation Part-No. Designation 009.859" Contact tip 056932 Stationary main contact, 010236" Flexible current strip instead of 047 640 if needed 011586" Flexible current strip 056941 Connecting lead 0125982 Flexible current strip 057352 Locktab 0125992 Flexible current strip 085253 MII 600 A: stationary main contact 017 182 Connecting lead 090982 Stationary main contact, 017 183 Connecting lead (left side) instead of 085 253 if needed 017 184 Connecting lead (right side) 262331" Contact holder (main contact) 017 185 Connecting lead 264 020 Contact holder (transition contact) 017 3552 Contact tip for transition contact (>200 A) 400004 Washer 018410 Connecting lead (left side) 450 038 Hex. head screw M5 x 30 018411 Connecting lead (right side) 450090 Hex. head screw M8 x 35 023117 Locktab 450335 Hex.head screw M5 x 20 046942 Contact holder 450352 Hex.head screw Mé x 12 047 020 Flexible current strip 450355 Hex. head screw M6 x 16 047 640 M I I 500 A: stationary main contact 450358 Hex. head screw M6 x 20 047 652 Pressure plate 450388 Hex. head screw M8 x 28 047 935 Washer 450500 Hex. head screw M6 x 22 048 053 Washer 451076 Recess head screw M6 x 16 049 039 Pressure plate 451082 Recess head screw M6 x 12 049 113 Tubular spacer 451087 Recess head screw M6 x 25 049823 Spring socket 451323 Washer 0518732 Contact tip 451325 Washer 052087 Locktab 451326 Washer 052206 Counterpiece 452357 Dished washer 056 434 Contact shell bottom 453977 Hex. nut M6 (self-locking) 056 445 Connecting piece 453978 Hex. nut M8 (self-locking) 056 452 Spacer (laminated paper) 453981 Hex. nut M5 (self-locking) 056 498 Bushing 550666 Compression spring 056 500 Transition resistor sheil 550694 Compression spring 056514 Locktab 550711" Compression spring 056 657 Connecting lead 550719 Compression spring 056916 Contact support 560 031 Molded insulator 056 930 Connecting lead Note: " For M I I 500 A, MII 600 A; delete in case of M111350 A 2 For M I I 350 A; delete i n case of M11 500 A und M i l 600 A MASCHINENFABRIK On-load tap changer type M A Parts designation for dwg. MRE Parts of the diverter switch, poles W & U (stationary contact system, laminated paper type) 894 451: 2E 40  018410 018411 bed a 450 ¢ A 3 [056 657 9) ALS Np 0569%0 osho41 if 017182 A AR v/ (@ MA) Q I 18 Q MASCHINENFABRIK On-load tap changer type M A MRE" REINHAUSEN Parts of the diverter switch, poles W & U (stationary contact system, laminated paper type) 894 451: 2 E 41  Part-No. Designation Part-No. Designation 009 859" Contact tip 085 253 M111 600 A: stationary main contact 010 236" Flexible current strip 090982 Stationary main contact, 011586" Flexible current strip instead of 085 253 if needed 0125982 Flexible current strip 092 378 Connecting lead 0125992 Flexible current strip 092 382 Connecting lead 012600 Connecting lead 092 383 Connecting lead 017 3552 Contact tip for transition contact (>200 A) 092 387 Connecting lead 023 117 Lock tab 262331" Contact holder 046 942 Contact holder 264 020 Contact holder (transition contact) 047 020 Flexible current strip 400 004 Washer 047 640 M I I 500 A: stationary main contact 400784 Cheese-head screw M6 x 16 047 652 Pressure plate (selfdocking) 047 935 Washer 400 852 Cheese-head screw M8 x 30 048 053 Washer (selfdocking) 049 039 Pressure plate 401 448 Cheese-head screw M6 x 10 049 113 Tubular spacer (selfdocking) 049 823 Spring socket 450 038 Hex.head screw M5 x 30 0518732 Contact tip 450 335 Hex.head screw M5 x 20 052087 Locktab 450 358 Hex.head screw M6 x 20 052206 Counterpiece 450 385 Hex.head screw M8 x 20 055925 Screening cap 450 387 Hex.head screw M8 x 25 056 445 Connecting piece 450 388 Hex.head screw M8 x 28 056 498 Bushing 450 500 Hex.head screw M6 x 22 056514 Locktab 451 076 Recess head screw M6 x 16 056 657 Connecting lead 451 087 Recess head screw M6 x 25 056930 Connecting lead 451 325 Washer 056 9 3 2 Stationary m a i n contact, 451 3 2 6 Washer instead of 047 640 if needed 452 357 Dished washer 056 941 Connecting lead 453 977 Hex.nut M6 (selfHocking) 064291 Washer 453 978 Hex.nut M8 (self-locking) 071936 Screening cap 453 981 Hex.nut M5 (selfdocking) 072059 Supporting element 550 666 Compression spring 072459 Supporting lug 550711" Compression spring 072460 Supporting lug 550719 Compression spring 073284 Washer 560 031 Molded insulator 073422 Screening cap Note: " For M11 500 A, MII 600 A; delete in case of M [11350 A 2 For M lll 350 A; delete in case of M Ill 500 A und M l 600 A MASCHINENFABRIK On-load tap changer type M A Parts designation for dwg. MRR" Parts of the diverter switch, poles W & U (stationary contact system, GFRP type) 896 464 : OE 42  452357 0716986 (60 kV) 055925 (110 kV) MASCHINENFABRIK On-load tap changer type M A REINHAUSEN Parts of the diverter switch, poles W & U 896 464 : OE — (stationary contact system, GFRP type) 43  Part-No. Designation Part-No. Designation 011105 Epoxy segment 056 919 Screening cap 012768 Contact braid 057 345 Tubular spacer 012770 Contact braid 057 801 Contact holder 012801 Contact braid 057 802 Contact holder 015991 Current strip 058 679 Support 015992 Current strip 200 151 Support 017 179 Protective spark gap 450043 Hex.head screw Mb x 22 017 209" Screening ring 450 062 Hex.head screw M6 x 28 017355 Contact tip for transition contact (>200 A) 450101 Hex.head screw M8 x 125 022417 Washer 450109 Hex.head screw M8 x 160 026 157 Washer 450 143 Hex.head screw M10 x 140 046 956 Tubular drive shaft 450355 Hex.head screw M6 x 16 046 970 Take-off bar 450939 Cheese-head screw M5 x 12 046987 Pressure plate 451086 Cheese-head screw M6 x 20 047 409 Tubular spacer 451323 Washer 047 412 Contact holder, main switching contact 451325 Washer 047738 Tubular spacer 451327 Washer 048 400 Spacer 452 063 Ball bearing 048633 Roller 452220 Circlip 048 869 Spacer disc 452350 Dished washer 050101 Tubular spacer 452997 Key 050 102 Tubular spacer 452998 Key 050103 Roller 453 447 Cheese-head screw M6 x 30 050319 Centering sliced spacer 453977 Hex.nut M6 (self-locking) 050387 Tubular spacer 453978 Hex.nut M8 (self-locking) 050504 Tubular spacer 453979 Hex.nut M10 (self-locking) 050535 Contact holder, transition contact 453981 Hex.nut M5 (self-locking) 050773 Locktab 550292 Insulating tube 051873 Contaét tip 550294 Tubular spacer 053 155 Clamping stud M10 x 290 550295 Tubular spacer 053667 Washer 550665 Compression spring 056 436 Epoxy guide plate 550668 Compression sping 056 472 Drive star top 560 163 Take-off contact case 056 484 Drive star bottom 587 036 Wire-wound resistor GWS 220, 056 548 Resistor holder 100 kiloohms Note: ¥ With laminated paper type only MASCHINENFABRIK On-load tap changer M lll 350 A Parts designation for d w g. MR reins Parts of the diverter switch, poles W & U : ‘ I —— (movable contact system) 894 452 ; 2E 44  —053155 7.) i 7 | / an MASCHINENFABRIK On-load tap changer M 111350 A REINHAUSEN Parts of the diverter switch, poles W & U 894 452: 2E EE—— {movable contact system) 45  973 453978 453977 050319 452220 ~~ (EB R \ dl IDR | 1°] == 45208 3 204 d C LT 1%). 048387 LR = 046970 ==1 D | —— 056 — — \ ——— ie —— Sor = — g A |B = TN CFE AT 046988 = i re ] ! oni 600A: 085252 n2 o s 52 048441 L]_2] La, = 048870 053186 047409 048869 —¢ 026 157 [— 650292 048870 048403 MASCHINENFABRIK On-load tap changer M Ill 500/600 A MR rensaisen Parts of the diverter switch, poles W & U 894 453: 2E (movable contact system) 46  011105 453981 451323 048633 056472 048869 026157 | 550202 048870 056 484 © 048403 048 400 500A: 010725 [=) 600A: 085 252 2 : Cog fe) E> 010736 53447 022013 ! 048400 | / TD f l ~ ThA 046956 056436 - (JJ ~ = [> Je | ~. ~~ + 048397 Te 058679 So N So ° 452063 450109— | 053667 } 452220 453979 453977 056916 (=) 017209 MASCHINENFABRIK On-load tap changer M l l l 500/600 A REINHAUSEN Parts of the diverter switch, poles W & U 894 453 ; 2E A A A—— (movable contact system)  Part-No. Designation Part-No. Designation L00 391 Drive shaft for tap-change monitoring system 088382 Bracket compl. 044 271 Axle 089 349 Lever for tap-change monitoring system 044 272 Bushing 400915 Dowel pin 047 250 Pawl 450385 Hex.head screw M8 x 20 047 251 Pawl 450710 Recess head screw M6 x 20 047 256 Slider 451444 Dowel pin 047 278 Rocker 451449 Dowel pin 047 279 Bushing 451520 Key 047 283 Bushing 451521 Key 047 372 Washer 451730 Recess head rivet 047 449 Eccentric cam 452 026 Ball bearing 047 450 Bolt 452 028 Ball bearing 047 483 Bolt 452206 Circlip 047 615 Rivet plate 452210 Circlip 047 620 Hub 452216 Circlip 047786 Bushing 452 221 Circlip 047 787 Guide bolt 452 256