Westinghouse DB-50 Instructions Manual
  1. Manuals
  2. Brands
  3. Westinghouse Manuals
  4. Circuit breakers
  5. DB-50
  6. Instructions manual
Westinghouse DB-50 Instructions Manual

Westinghouse DB-50 Instructions Manual

Air circuit breakers
Hide thumbs Also See for DB-50:
Table of Contents

Advertisement

Quick Links

Co
tvf!Je---r-
j.. u
bRtctr-t"r d
Instructions for Types DB-50 and
DBF-16 Air Circuit Breakers
Westinghouse Electric Corporation
&
Assembled Switchgear
I.B.
Effective November,
33·850-3A,
ri
frd J
_
Devices Division, East Pittsbur
Supersedes I.B.
1962.
g
h, Pa.
33-850-3, July, 1959

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the DB-50 and is the answer not in the manual?

Questions and answers

Related Manuals for Westinghouse DB-50

Summary of Contents for Westinghouse DB-50

  • Page 1 J tvf!Je---r- j.. u bRtctr-t"r d Instructions for Types DB-50 and DBF-16 Air Circuit Breakers Westinghouse Electric Corporation & Assembled Switchgear Devices Division, East Pittsbur h, Pa. I.B. Effective November, Supersedes I.B. 33·850-3A, 1962. 33-850-3, July, 1959...

  • Page 2: Table Of Contents

    Page 2 Table of Contents Page Part Receiving, Handling, and Storing • Inspection Storing Part Installation • • • • • Connections Part 3 Maintenance • • • Pole Unit • � . • • • Contacts Maintenance of Contacts . •...
  • Page 3 Page Figure • • • • DB-50 Outline Dimensions and Mounting Details • Typical Wiring Diagrams - Type DB-50 Circuit Breaker • • Cros s-sectional View of Type DB-50 Circuit Breaker • • • • Type DB-50 Spring Clos ing Assembly Series Overcurrent Tripping Device with Long Delay and •...
  • Page 4 Page 4...
  • Page 5 . Consul t Westinghouse engineering and serv­ ice personn e l for recommendations pertaining to special operating or maintenance...

  • Page 6: Receiving, Handling, And Storing

    Page 6 PART RECEIVING, HANDLING, AND STORING Rotate the manual operating handle Type " DB-50" air circuit breakers , with slowly in a clockwise direction to move the all attachments mounted in place, are contacts toward the closed position. shipped in special cartons.

  • Page 7: Part Installation

    Page 7 PART IN STALLATION Type "DB-50" circuit breakers are fur­ CONNECTIONS nished as complete unit assemblies and the installation consists of: (1) bolting them to Typical circuit breaker wnmg diagrams the supporting framework or structure; (2) are shown in Fig. 2. The connecting cables connecting the current-carrying cables or or bus bars should have adequate current­...

  • Page 9: Maintenance

    The closing spring assembly is shown in Fig. 3A. ,_pontacts . (See Fig. 3.) The DB-50 arcing contact should touch first Rotating the closing handle clockwise on closing, open last on opening. Contact raises the lift link and lower spring guide to compress the closing spring.
  • Page 10 IS LATCHED DE-ENER�I"Z.ED LATCH UNLATCHED RESET PROVIDED X"COI L IS PAGE CO!Hil:OL DE: ·EN.E��rz.ED 4-7 Al�I0 9 A 1569 4-7 A 15 G� VOL T I\GES Z:.0-460 V i\C Fig. 2 - Typical Wiring Diagrams - Type DB-50 Circuit Breaker...
  • Page 11 DB-50 CIRCUIT BREAKER Page 11 STEEL PANEL ARC CHUTE 1600 AMPERES. 600 VOLTS A-C MOVING ARCING CONTACT MECHANISM STUD PUSH TRIP HANDLE CLOSING O VERCURRENT SOL ENOID TRIPPING DEVICE TRIPPED OPEN(RESET) CLOSED Fig. 3 Cross-Sectional View of Type DB-50 Circuit Breaker...

  • Page 12: Overcurrent Tripping Device

    (3) to drop into brass rating coils ranging from 2 0 0 to 1600 am- RO L LER MECHANISM LEVER HANDLE LATCH PLATE UPPER SPRING GUIDE SPRING LOWER SPRING GUIDE SPRING MECHANISM Fig. 3A - Type DB-50 Spring Closing Assembly...

  • Page 13: Installation And Removal

    Page 13 Fig. Series Overcur­ Fig. Series Overcuccent rent Tripping Device with Tripping Device Showing the Long Time and Instan­ Assembly of Calibration Case taneous Element to Magnetic Circuit. peres. The construction , except for the longer than specified above are not used, coils, is similar for all ratings.

  • Page 14: Construction

    Page 14 1 ... ""• • I?I!LEA!Tr YlflVL f¥C11(;K lt-�5T.O.N.,._eoJ5'11 " Lv&. "UO""'"""' tl05C ...: : . .. - tt --( � Fig. Cross-Sectional View of Series Overcurrent Tripping Device with Long Delay and Instantaneous Elements can readily be moved upward to check the The tripping device consists of two main subassemblies namely: tripping action.

  • Page 15: Time-Current Classification

    Page lS Time-current Classification The calibration for the various elements are: The overcurrent tripping devices can be supplied with any combination of the three Long delay pick-up tripping elements , namely, long delay, short delay, and instantaneous elements. Adjustable with calibrated marks at 80- most popular combinations are listed below: 100-120- : 1 40 and 160 percent of coil rat­...

  • Page 16: Tripping Characteristics Of Standard Series Overcurrent Tripping Device With Long Delay And Instantaneous

    8 °0 g 00 'i88 Page 16 current i n percent of breaker tri p un� ratigq § § o c oc o 7 oo �gg � :: f- - - H ++:=====:==:=� =:=�:� : :� >;;�\ � ·�===�=:=::\ : : : j r _j long delay pickup settings-adjustabl e with percent of tri p uni t rating 80,100,120,140,...

  • Page 17: Time-Current Characteristics

    Page 20 A quick release valve (shown in Fig. 6 - The tripping time will remain constant until short delay tripping parts) which functions interrupted by the instantaneous or short as described for dual overcurrent tripping delay pick-up wherever they occur. For the device .
  • Page 18 Page 19 � --�-- Fig. Schematic Diagram of Standard Overcurrent Tripping Device with Adjustable Long Delay and Adjustable Instantaneous Element · 3 chamber T by the various valves H and K. long delay will begin to operate is deter­ VVhen the diaphragm has reached approx­ mined by the long delay pick-up adjusting imately 6 0 percent of its travel, a quick knob P, Figure 10.
  • Page 19 • • • ·- � ·- • 1 • ""' -.j-·l._ •• ''!:' . • "':!- . -�·-..
  • Page 20 "'Y..., �- ',, , 'i > '·�:: · -i(;!/ ' f Recommended Spare Parts fot ""�'� )-"·'<:"-- · ' STYLE NUMBER NAME OF PART NUMBER NUMBER PER RECOMMENDED ALWAYS GIVE BREAKER BREAKER OR S.O. REFERENCE REFERENCE FOR BREAKERS DEV I CE 2 TO 5 6 UP AUX ILl ARY SW I TCH...

  • Page 21: Tripping Characteristics Of Special Series Overcurrent

    � R.;\,�'j � � � �� Page 18 � CURRENT I N ::AW � � � � g � ::5 a;; � s o 1o s o 9 o e � 1000 � � - C�- >- ---1 - -f+t·i--1 - .

  • Page 22: Tripping Characteristics Of Selective Series Overcurrent

    Page 17 current in percent of breoker trip unit rating § 0 0 8 0 g o 8 ° 8 ° o o o o o o 0 8 8 8 8 8 "' 5 6 7 8 9 10 "' �...
  • Page 23 Page 21 � Fig. - Schematic Diagram of Selective Series Overcurrent Tripping Device with Adjustable Long Delay and Short Delay Elements --�·- Fig. 1 2 - Schematic Diagram of Special Series Overcurrent Tripping Device with Instantaneous Element Only...

  • Page 24: Discriminator For Tripping Device

    Page 22 - f'tN BK/i!.· Ct.. <> S4D 8KR· 0PEN DIISN fbT P15TOI( TR!f' ---- - L - --- j) ISC !e!MI/'(A TO� T Y f' E OVEN. cU�JCE tVT lktP f'I(ONT V tEW D B- S o Fig. Discriminator for Tripping Device Instantaneous P ick-Up been calibrated and the calibration plate marked at 500-750 and 1000 percent of the...

  • Page 25: Control Relay

    Pa ge 23 � FRONT Fig. Closing Solenoid - Construction Details setting before shipment. A different setting CONTROL RELAY can be obtained by carefully turning the adjusting knob with the help of a small The control relay (see Fig. 15) mounts di­ screwdriver inserted in the slots for that rectly under the auxiliary switch.

  • Page 27: Shunt Trip A Ttachment

    Page 25 E nergize relay operating coil. Slowly SHUNT TRIP A TTACHMENT close the breaker manually. The relay release arm should operate the relay trip The shunt trip mounts on top of the platform assembly and the relay trip assembly immediately to the right of the operating mechanism.

  • Page 28: Undervoltage Trip A Ttachment 2

    Page 26 Inspection Maintenance Check for loose bolts and faulty coil. Hold the trip bar down and close the breaker manually. Release the trip bar slowly, allowing the undervoltage trip spring to UNDERVOLTAGE TRIP ATTACHMENT raise the trip bar and trip the breaker. The undervoltage trip mounts on top of the Maintenance platform, to the right of the shunt trip .

  • Page 29: Field Discharge Switch

    FIE LD DISCHARGE SWITCH desired. An arc chute is always supplied to interrupt motor starting secondary cur­ The DBF-16 breaker is a two-pole DB-50 rents. breaker having special arc chutes and modi­ fied arcing contacts plus a field discharge Inspection switch mounted on the center pole (Fig.

  • Page 30: Reverse Current Trip Attachment - Construction Details

    Page 28 LOCKNUT SPR I NG ,--- - - -- - __ _ 18 - Fig. Undervoltage Time Delay Attachment - Construction Details TR I P C R A N K CO I L A S S E M B LY--++� FR O N T Y O K E L--·-·...

  • Page 31: Auxiliary Switch

    Page 29 Maintenance ALARM SWITCH ATTACHMENT Remove power from the breaker, clean the The alarm switch mounts above the shunt contacts if necessary, check the contact trip attachment (see Fig. 22) and will ener­ separation and adjust if necessary. Check gize the alarm circuit on all opening op­...

  • Page 32: - Field Discharge Switch - Construction D Etails

    Page 30 ADJ U ST OP E RATING ROD TO S E C U R E 1 / 1 6 TO 3/1 6 B R EAK OF F I E L D D I SCHARG E CON TACT W H E N B R E AK E R ARCING CON TACTS TOUCH ON CLOSING BREAKER CLOSED...

  • Page 33: Key Lock Attachment

    Page 3 1 1\li\RM SWIICH CROSS B,t>.,R · -- __J.) Fig. Alarm Switch Attachment - Construction D etails Maintenance F ig. 24.) When the key interlock attachment is furnished, the key lock attachment cannot The device is non-adjustable . Check for be supplied.
  • Page 34 � "d "' �� I I . ·� : -r::ci-:� {b�7 s��PP���0�u��EsET�::��. Fig. 23 Electric Lockout Attachment - Construction Details...

  • Page 35: Key Lock Or Key Interlock Attachment - Construction Details

    Page 33 LOCK CYLINDER 24 - Fig. Key Lock or Key Interlock Attachment - Construction Details that the common voltages for 6 0 cycles can Inspection be connected to the appropriate terminal on the unit. A terminal block is mounted There are no moving p arts .

  • Page 36: Rectifier Unit For A-C Undervoltage And A-C Electric Lockout

    Page 3 4 T��R 'Tr� R EC T I F I ER � A C. VO L T A G E SO U R C E A N D / O R S C H E M A T I C �...
  • Page 37 .._ Page 35 Recommended Spare Parts for D B S O Air B rea k er STYLE NUMBER �AME OF PART NUMBER NUMBER PER RECOMMENDED ALWAYS GIVE BREAKER BREAKER OR REFERENCE FOR BREAKERS S . O . REFERENCE DEVICE 2 TO 5 AUX ILl ARY SWITCH Fl G.

This manual is also suitable for:

Dbf-16

Table of Contents