Westinghouse DH, Instructions Manual

Page 1: ... for Rated uous Max Design At Rated Max Amperes 60 CYCLES TYPE Rated MYA KV INT KV Voltage MVA 50 DH 150 E 50 DH 150 E 3 5 1200 150 4 16 4 76 21 000 21 000 35 000 35 000 25 000 25 000 37 500 37 500 4 16 4 76 3 5 2000 150 50 DH 250 E 50 DH 250 E 4 16 4 76 3 85 1200 250 4 16 4 76 3 85 2000 250 WESTINGHOUSE ELECTRIC CORPORATION SWITCHGEAR DIVISION EAST PITTSBURGH PA FEBRUARY 1959 EAST PITTSBURGH PLAN...

Page 2: ... In Device Test Position Operating Position Interlock Secondary Contacts Ground Contact Puffer Assembly Mechanism Operated Control Switch Secondary Control Wiring Pages 8 22 8 8 9 9 11 11 11 12 12 12 12 12 13 16 17 19 20 20 20 21 21 22 22 INSTALLATION Part Four Installation Pages 22 25 22 ADJUSTMENT Part Five Mechanism Tripping Latch Cut Off Switch Latch Check Switch Contacts Pages 25 26 25 25 25 ...

Page 3: ...r Contacts Viewed from Rear Type 50 DH 250 E 1200 Amp Breaker Contacts Viewed from Rear Type 50 DH 150 E 250 E 2000 Amp Breaker Contacts Viewed from Rear Type 50 DH 150 E 1200 Amp Breaker Contacts Viewed from Front Type 50 DH 250 E 1200 Amp Breaker Contacts Viewed from Front Type 50 DH 150 E 250 E 2000 Amp Breaker Contacts Viewed from Front Arc Chute Arrangement Partially Assembled Arc Chutes Leve...

Page 4: ...rcuits from 2 3 to 15 kv Each of the type DH air circuit breakers is three pole electrically operated and is built as a complete horizontal drawout unit for metal clad switchgear Breaker units of the same rating are interchangeable so that changing breakers is a matter of minutes Since they are drawn out horizontally no lowering or lifting is necessary Steel barriers and automatic interlocks preve...

Page 5: ...arc chutes on this breaker are of the center coil design in which the magnetic circuit is H shaped with the cross member of the H passing through the center of the arc chute The blowout coils are wound around the cross member of the H and are located inside the arc chute jacket With this arrangement the blowout magnet becomes an integral part of each arc chute assembly To provide accessibility for...

Page 6: ...OVING CONTACT ARM SHUTTER ROLLER OPERATING ROD LEVERING IN DEVICE ARM TRIP LEVER LEVERING IN DEVICE OPERATING SHAFT MECHANISM PANEL MAINTENANCE CLOSING HANDLE SOCKET FLANGED WHEELS FIG 3 Type 50 DH 250 E 1200 Ampere Breaker with Barrier removed Front View 6 Courtesy of NationalSwitchgear com ...

Page 7: ...DESCRIPTION I B 32 251 3 50 DH 150 250 AIR CIRCUIT BREAKERS FIO 4 Type 50 DH 250 E 1200 Ampere Breaker with Barrier removed and Arc Chutes tilted back for Inspection 7 Courtesy of NationalSwitchgear com ...

Page 8: ...ble of Approximate Weights In Pounds BREAKER WITHOUT CHUTE BREAKER AMPERE RATING SINGLE BARRIER ASSEM COM TYPE PLETE BREAKER ARC CHUTE BLY BARRIER 50 DH 150 E 50 DH 150 E 1200 2000 695 85 80 1030 960 85 100 1315 50 DH 250 E 50 DH 250 E 1200 no 695 85 1110 2000 960 110 100 1390 PART THREE OPERATION Before placing the circuit breaker in service it is advantageous to become familiar with the con stru...

Page 9: ...mary latch which disengages the tripping latch This allows the tripping latch to rotate counterclockwise and release the tripping cam so that it is free to rotate counterclockwise Without the restraining force of the cam and cam links the upper and lower trip free links collapse under the force of the contact springs and the accelerating springs on the puffer rods The junction of these links moves...

Page 10: ...OPERATION FIG 6 Solenoid Operating Mechanism Diagram of Tripping Positions 10 Courtesy of NationalSwitchgear com ...

Page 11: ...core and limits its travel to about inch A thin brass washer prevents the moving core from being retained by residual magnetism in the raised posi tion after the coil is de energized Cut Off Switch The cut off switch is a single pole normally open contact which acts with the breaker control relays to cut off the closing coil cur rent after the breaker is closed The switch is oper ated by an arm at...

Page 12: ...lever spring over comes the magnetic attraction of the cores and rotates the reset lever clockwise As the reset lever rotates the pin pushes against the latch to release it from its latch plate When the latch releases the trip spring rotates the trip lever to trip the breaker The linkage is reset by the trip free lever of the mechanism as the breaker opens For time delay release on tripping a very...

Page 13: ... Fig 12 The 1200 ampere Type 50 DH 250 E breaker stationary contact is shown in Fig 13 and is similar with the exception that the arcing contact is wider The 2000 ampere rating employs six fingers on each stationary contact and is shown in Fig 14 Cooling fins are located on each side of the contact With this contact design all current breaking and interrupting parts are completely enclosed by the ...

Page 14: ...AIN CONTACT 1 T PUFFER NOZZLE MOVING CONTACT ARM FIG 10 Type 50 DH 250 E 1200 Ampere Breaker Contacts Viewed from Rear MOVING ARCING CONTACTS P UFFER STATIONARY ARCING CONTACT UPPER CONTACT FOOT MOVING MA CONTACT MOVING CONTACT ARMS INNER OUTE FIG 11 Type 50 DH 150 E 250 E 2000 Ampere Breaker Contacts Viewed from Rear Courtesy of NationalSwitchgear com ...

Page 15: ...ING CONTACT ARM ARCING CONTACT SPRINGS i 0 FIG 12 Type 50 DH 150 E 1200 Ampere Breaker Contacts Viewed from Front STATIONARY ARCING CONTACT UPPER CONTACT F001 STATIONARY MAIN CONTACT FINGERS 4 MOVING ARCING CONTACTS ARCING CONTACT EYE BOLT MOVING CONTACT ARM ARCING CONTACT SPRINGS FIG 13 Type 50 DH 250 E 1200 Ampere Breaker Contacts Viewed from Front Courtesy of NationalSwitchgear com ...

Page 16: ...e influence of the powerful magnetic force As the arc moves to the closed end of the slots it is restric ted lengthened and cooled All of these forces re sult in rapid de ionization of the arc space and for the arc to maintain itself it must continuously ionize fresh gas At current zero the formation of new ioni zation momentarily ceases but the de ionization con tinues so that dielectric strength...

Page 17: ...0 250 AIR CIRCUIT BREAKERS I Arc Ch v IRING IN D VICE of pa 5sembl DH rrl of fk tin uell Th ick rea tee break the pr vided beer 5imil pa ea ea baft ba bee red on On each roll of th rpe ral th Courtesy of NationalSwitchgear com ...

Page 18: ...nt and the indicator on the mechanism panel will point to the word OPERATE FIG 17 Levering In Device in position for Rolling into Cell able crank engages another shaft in the right front corner of the breaker which turns the arms through a worm gear and pinion arrangement Before a breaker is rolled into a cell the arms with rollers at each side of the breaker must point to the rear and slightly do...

Page 19: ... in device cannot be engaged unless the breaker contacts are open Put the crank on the operating shaft push in and rotate to engage the coupling and turn counterclockwise until the breaker returns to the test position Remove the crank The breaker may now be operated at the test position or rolled out of the cell TEST POSITION The breaker may be rolled into the metal clad cell until the rollers on ...

Page 20: ...the split coupling the bell crank casting lifts the interlock pin which in turn will block any movement of the puffer rod Thus the solenoid operating mechanism cannot move from the open position As the crank is turned a cam on the levering in shaft holds the interlock pin in the raised position until the arms are at either end of their travel At this time the spring on the interlock pin will pull ...

Page 21: ...hen raise up on the handle to the end of travel See Fig 21 To disengage the secondary contacts the maintenance closing handle is inserted into the socket and lowered If the breaker is levered into the operating position the secondary plug and slide will automatically return to the normal position and the latch will hold it in place when the breaker is later moved to the test position PUFFER ASSEMB...

Page 22: ...of flexible stranded copper wire having flame retard ant moisture resistant insulation The standard breaker internal wiring is shown on Connection Diagram Fig 23 When an undervoltage trip device is used on the breaker its coil is connected between secondary contacts 15 and 16 and the a contact at the end of the auxiliary switch is not wired SW CUT OFF 7 8 9 o o o 7 8 9 o o o SW 10 II 12 o o o 13 1...

Page 23: ...lose breaker by hand Place the mainten ance closing handle in the closing socket of the mechanism and push down to close the breaker As the contacts touch near the end of the stroke the force necessary to latch the breaker increases rapidly 4 Check contact adjustment The breaker main contacts are properly adjusted when the over travel at the bottom of the outside stationary contact fingers is betw...

Page 24: ...nd rotate counterclockwise until the arms come around to the end of the travel against the solid stop The breaker must be open to engage the levering in device 12 Place breaker in test position Position the breaker in the cell and roll it in until it comes up against the solid stop This is the test position 13 Engage secondary contacts Place the maintenance closing handle in the secondary con tact...

Page 25: ...ng Latch If a breaker fails to close con tacts although the moving core of the mechanism moves to the closed position a probable cause is failure to reset Refer to C Fig 6 The gap indi cated between the tripping latch roller and cam is an essential requirement to permit the tripping latch to fall into the cam notch Watch the trigger handle with words lift to trip it should return to the horizontal...

Page 26: ...cal operations to be sure they are quick snappy and positive and that there is no tendency of any parts to stick If there is any stickiness or sluggish motion operate slowly by hand to locate the place with high friction See paragraphs on Lubrication It is recommended that breakers which remain closed continuously without any automatic operations be given several exercising 1 operations and a comp...

Page 27: ... slight burning on the main contacts Also after many operations the main contacts will some times become roughened A fine flat file should be used lightly on the main contact silvers removing only enough to take off the high spots In other cases the surfaces may become glazed or shiny and this may be corrected by the use of fine sandpaper A moderate amount of pitting on the main contact surfaces w...

Page 28: ...e lubricants only follows principles of good mechanical practice For many operating parts lubricants can be avoided In cer tain other parts the use of special lubricant is de sirable and beneficial PROVIDED IT IS DONE CAREFULLY This means applying it in small quan tities to avoid drippings and accumulation Experi ence will dictate the amount required Those break ers having only a few operations pe...

Page 29: ...at the closing latch and shaft and energize the close coil for one or two seconds several times The overtravel should be approximately mini mum to 2 maximum With wear in the link holes and pins this overtravel may decrease Adjustment is made with steel shim washers between the magnet back plate and the four large magnetic return studs This will change the position of the stationary core with respe...

Page 30: ... the rotor shaft in the correct order The various widths are given in Fig 29 with the 2 and 2 spacers starting at the third position and alternating to the end of the rotor INSULATION Flame retardent glass mat polyester insulating materials are used in high voltage air circuit break ers for bushing ties barriers braces arc chutes and similar purposes where it has been found to be more suitable tha...

Page 31: ... 4 Cotter Pins 5 Left Hand Moving Contact Arm 6 Hinge Spring Washers 7 Operating Rod 8 Adjusting Stud 9 Rod End 10 Lockwashers 11 Locknut Right Hand Thread 12 Locknut Left Hand Thread 13 Moving ArcingContact Spring Outer 26 Moving Arcing Contact 27 Truarc Rings 28 Pin 29 Moving Main Contact 30 Nuts 31 Lockwashers 32 Main Contact Bolts 33 Hinge Bolt 34 Hinge Spacer 35 Castelated Nut 36 Cotter Pin 3...

Page 32: ...sulating Strip 4 Arcing Contact Bolt 5 Stationary Arcing Contact 6 Finger Stop Casting 7 Lockwashers 8 Bolts 1 Stationary Contact Assembly Complete 2 Bushing Stud and Contact Foot Assembly 3 Lockwasner FIG 26 Type 50 DH 150 E 1200 Ampere Stationary Contact Assembly 32 Courtesy of NationalSwitchgear com ...

Page 33: ...ower Trip Free Links 22C Cam Links 22D Washers 22E Pin Joining Upper and Lower Trip Free Links 22F Pin Joining Cam and Cam Link 22G Tripping Cam 22H Upper Trip Free Link 221 Cam Stop Rollers Pin for Upper Trip Free Link 24 Rubber Stop Bumpers 25 Closing Latch 26 Retrieving Spring 27 Non Trip Free Lever 28 Washers 29 Bushing 30 Operating Center Pin 31 Mechanism Stop Bolt and Locknut 32 Hand Trip As...

Page 34: ...Instruction Book I B 32 251 3 Only those fea tures which apply to the Types listed above are covered by these instructions These instructions provide additional information and serve as a guide to references of sections in Instruction Book 32 251 3 for easy reference NOVEMBER 1959 C O R P O R A T O N E L E C T R I C W E S T N G H O U S E ASSEMBLED SWITCHGEAR DEVICES EAST PITTSBURGH PA EAST PITTSBU...

Page 35: ...inuous 60 Cycle Rating 1200 2000 A 1200 A 1200 2000 A 1200 2000 A 1200 2000 A 13800 V 13800 V Rated Voltage 7200 V 7200 V 13800 V 15000 V 15000 V Maximum Design Voltage 15000 V 8250 V 8250 V Minimum Voltage For Interrupting Capacity 11500 V 6600 V 4600 V 6600 V 6600 V Interrupting Current At Rated Voltage 21000 A 40000 A 6300 A 20000 A 10600 A Maximum Interrupting Current 22000 A 25000 A 44000 A 1...

Page 36: ...cell In the lower part of the frame is also lo cated the levering in device for moving the breaker into final contact engagement This de vice is interlocked with the mechanism to prevent inserting or withdrawing the breaker with the contacts closed Also located in the lower part of the frame are the secondary contacts for automatically disconnecting the control wiring when the breaker is withdrawn...

Page 37: ...ting the arc chutes FIG 3 CIRCUIT BREAKER WITH MAIN BARRIER REMOVED AND ARC CHUTES RAISED A barrier assembly is placed on the breaker before it is rolled into its cell The front sheet is 1 8 inch steel to form a grounded barrier between personnel and live parts when the unit is in the cell dling right unit placed side by side engage the barriers at the top bolts which attach to the frame structure...

Page 38: ...nd with a tie on the trip lever to prevent tripping After the breaker is unpacked and the shipping ties and braces re moved take off the tie on the trip lever and trip the breaker Then close the breaker carefully by hand using the removable hand closing lever Make certain that all parts are functioning properly in that there is no binding or excessive friction As the con tacts touch near the end o...

Page 39: ...e steel barrier is placed flatly against the compartments at a slightly higher elevation and slowly lowered until the hooks engage the pins at both sides The lower end of the steel barrier is then secured to the frame structure with two hex head bolts making certain that the barrier is vertically straight in position to enter the cell opening 6 The breaker is now ready to be operated electrically ...

Page 40: ...ed slots The slots are off set so that as the plates are stacked with the slots alternating from one side to the other the arc must take a serpentine path as it moves up into the arc chute thus increasing the length of the arc To either side of the main interrupter stacks are two metallic arc horns to which the arc transfers from the arcing contacts The front arc horn is connected electrically to ...

Page 41: ...the arc chute to position shown in Figure 3 6 It is important that the arc chutes be raised until the indicator on the front of the breaker shows that the full travel of the levering in device has been used This releases the mechanism interlock and permits the breaker to be closed and tripped either electrically or manually with the arc chutes in the raised position To lower the arc chutes and pre...

Page 42: ...equired identify the breaker type and rating The breaker nameplate will MOTOR OPERATED BREAKERS A separate instruction book is supplied for breakers having a motor spring type of clos ing mechanism and are supplied with the order involving this type of equipment 9 Courtesy of NationalSwitchgear com ...