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Instruction Book    

IB182012EN   March 2017   www.eaton.com

50DH-VR-50AXU / 50XU / 75U / 75ARU - 600 / 1200A

Replacement Circuit Breaker

5.3.2    50-DH-VR-50 XU/75ARU (REAR RACKING)

a.  Place the circuit breaker in the withdrawn position out of the cell. 

The racking handle is not required for this position and the racking 

system interlocks are not automatic outside the cell. The circuit 

breaker can be mechanically operated in this position if the position 

mode indicator reads “TEST/OPERATE”. Extreme care should be 

exercised to avoid inadvertent operation and possible injury or 

equipment damage.

 WARNING

THE CIRCUIT BREAKER CAN BE OPERATED WHEN WITHDRAWN FROM 

THE CELL AND EXTREME CARE SHOULD BE EXERCISED TO AVOID 

INADVERTENT OPERATION AND POSSIBLE INJURY AND/OR EQUIPMENT 

DAMAGE.

b.  From the withdrawn position, ensure the circuit breaker is open 

and the mechanism is completely discharge. Engage the racking 

handle and rotate the racking handle counter-clockwise as far as 

possible and align the circuit breaker wheels with the guide rails of 

the cell. (See Figure 5.6)
c.  Check that the closing spring status indicator reads “OPEN”. 

Manually trip, close, an trip the circuit breaker as needed to obtain 

this status.
d.  Push the circuit breaker into the cell until all the wheels 

are on the cell floor. The racking arm rollers will not meet the 

guide slots and the shutters have not begun to open. This is the 

“DISCONNECT” position.

 WARNING

THE SHUTTER WILL RISE POSSIBLY EXPOSING HIGH VOLTAGE BEFORE 

THE RACKING ARM ROLLERS ENGAGE THE GUIDE SLOTS. EXTREME CARE 

SHOULD BE EXERCISED TO AVOID POSSIBLE INJURY OR EQUIPMENT 

DAMAGE.

e.  Continue pushing the circuit breaker into the cell. The shutters 

will start to rise. The circuit breaker will travel approximately eight 

(8) inches from the “DISCONNECT” position before the racking arm 

rollers meet the guide slots.
f.  To rack the circuit breaker further into the cell, engage the racking 

handle and rotate the racking handle clockwise approximately 1 

turn. The position mode indicator (Figure Set 3.3) will reflect “TEST/

OPERATE”. In the “TEST” position, the circuit breaker can be closed 

and tripped manually and electrically, thus allowing maintenance test 

or checks. To operate the circuit breaker electrically, the secondary 

disconnect must be engaged at this time. Release the secondary 

disconnect slider by pulling the catch pin and pushing the slider 

toward the rear several inches. The slider is located on the lower left 

area of the circuit breaker frame. Push on the front side flat surface 

of the slider until the secondary disconnect can be felt to be fully 

engaged with the secondary disconnect of the switchgear.
g.  To advance from the “TEST” position, continue turning the 

racking handle clockwise. The circuit breaker will travel approximately 

4.25 inches. Towards the end of travel, the racking torque will 

increase due to the additional resistance of the primary disconnect 

contact fingers engaging the cell copper. The circuit breaker will be 

considered in the “CONNECT” position when the position indicator 

reads “TEST/OPERATE”. This indicates that the trip linkage is 

released and the circuit breaker is now ready for service.

5.4   REMOVAL PROCEDURE
5.4.1   50-DH-VR-50 AXU/75U (FRONT RACKING)

a.  To remove the circuit breaker from the cell, it must be in the open 

position. Ensure the circuit breaker is open and engage the racking 

handle. Move the circuit breaker out by rotating the racking handle 

counter-clockwise. The circuit breaker will start coming out of the 

cell before the secondary disconnect or primary disconnects are 

disconnected. The circuit breaker will be in a non-operable mode 

and will be prevented from closing if any attempt to close it is made 

in the intermediate position. The shutters will close after the main 

primary disconnects have cleared, isolating the circuit breaker from 

the power source. Continue racking out until the position mode 

indicator shows “TEST/OPERATE” and the shutter indicator shows 

closed. The circuit breaker is in the “TEST” position and the trip 

mechanism is released, allowing the circuit breaker to be operated 

either electrically or mechanically. If you desire to electrically open 

or close the circuit breaker in the “TEST” position, the secondary 

disconnect must be reengaged and the racking handle removed.
b.  To remove the circuit breaker from the “TEST” position to the 

“DISCONNECT”, the circuit breaker must be tripped if closed, the 

racking handle reinserted, and the secondary disconnect should be 

disengaged. Rotate the racking handle counter-clockwise until the 

racking mechanism movement is halted by the racking mechanism 

stop. When moving out of the “TEST” position, a close signal will 

combine with a trip signal from the interlock cam to force a trip-free 

condition. This will cause the charging springs to discharge leaving 

the circuit breaker in the open position. The racking handle should 

be removed at this point. The circuit breaker is ready to be removed 

from the cell.
c.  To remove the circuit breaker from the disconnected to the 

withdrawn position, the circuit breaker is pulled manually by the 

pull handle located immediately above the position mode indicator. 

The racking handle is not required between the withdrawn and 

disconnected positions. 
If it is desired to leave the circuit breaker in the cell instead of 

moving it from the test position to the completely withdrawn 

position, rotate the racking handle counter-clockwise one rotation. 

This will place the circuit breaker in a “trip-free” mode but will not 

discharge the closing springs. This prevents unnecessary wear to the 

circuit breaker mechanism.

5.4.2   50-DH-VR-50 XU/75ARU (REAR RACKING)

a.  To remove the circuit breaker from the cell, it must be in the open 

position. Ensure the circuit breaker is open and engage the racking 

handle. Move the circuit breaker out by rotating the racking handle 

counter-clockwise. The circuit breaker will start coming out of the 

cell before the secondary disconnect or primary disconnects are 

disconnected. The circuit breaker will be in a non-operable mode 

and will be prevented from closing if any attempt to close it is 

made in the intermediate position. Continue racking out the circuit 

breaker until the position mode indicator reads “TEST/OPERATE”. 

The circuit breaker is in the “TEST” position and the trip mechanism 

is released, allowing the circuit breaker to be operated either 

electrically or mechanically. If you desire to electrically open or close 

the circuit breaker in the “TEST” position, the secondary disconnect 

must be reengaged and the racking handle removed.

 WARNING

THE SHUTTERS ARE OPEN IN THE “TEST” POSITION. CARE SHOULD BE 

EXERCISED WHEN OPERATING THE CIRCUIT BREAKER MECHANICALLY 

OR ELECTRICALLY OR POSSIBLE INJURY AND/OR EQUIPMENT DAMAGE 

COULD RESULT.

b.  To remove the circuit breaker from the “TEST” position, continue 

turning the racking handle in a counter-clockwise direction until a 

mechanical stop is achieved. Using the handle located above the 

position mode indicator, pull the circuit breaker towards the front of 

the cell until the shutters fully close isolating the circuit breaker from 

the power source. This is the “DISCONNECT” position.
c.  To remove the circuit breaker from the cell, continue pulling 

the circuit breaker towards the front of the cell using the handle 

provided. The circuit breaker will encounter no stops and will be able 

to be pulled completely clear of the cell. The racking handle is not 

required.

Summary of Contents for 50DH-VE-50AXU-1200A

Page 1: ...struction Book IB182012EN 50DH VR 50AXU 50XU 75U 75ARU 600 1200A Replacement Circuit Breaker Supersedes March 2003 Effective 50DH VR 50XU 75ARU 1200A Rear Racking Device 50DH VR 50AXU 75U 1200A Front Racking Device ...

Page 2: ...an Eaton sales office should be consulted Sale of the product shown in this literature is subject to the terms and conditions outlined in appropriate Eaton selling policies or other contractual agreement between Eaton and the purchaser THERE ARE NO UNDERSTANDINGS AGREEMENTS WARRANTIES EXPRESSED OR IMPLIED INCLUDING WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE OR MERCHANTABILITY OTHER THAN THOSE ...

Page 3: ...TION DESCRIPTION 17 4 13 1 50DH VR 50AXU 75U FRONT RACKING 17 4 13 2 50DH VR 50XU 75ARU REAR RACKING 18 4 14 MISCELLANEOUS ITEMS 20 4 14 1 GROUNDING CONTACT 20 SECTION 5 INSPECTION INSTALLATION 21 5 1 EXAMINATION FOR DAMAGE 21 5 1 1 NAMEPLATE VERIFICATION 21 5 2 CELL MODIFICATIONS 21 5 2 1 CELL CLEARANCE MODIFICATIONS FOR 50 DH VR 50AXU 75U FRONT RACKING 21 5 2 2 CELL CLEARANCE AND SHUTTER MODIFIC...

Page 4: ...H VR 50 XU and 75RU have these arms located at the rear sides of the circuit breaker These two configurations are not interchangeable The correct type must be specified during order entry WARNING SATISFACTORY PERFORMANCE OF THESE CIRCUIT BREAKERS IS CONTINGENT UPON PROPER APPLICATION CORRECT INSTALLATION AND ADEQUATE MAINTENANCE THIS INSTRUCTION BOOK MUST BE CAREFULLY READ AND FOLLOWED IN ORDER TO...

Page 5: ...ircuit Breaker Table 2 50DH VR 50DH VR 50AXU 75U Front Racking Device Shown Circuit Breaker Type Existing Circuit Breaker Rated Continuous Current at 60 Hz Amps A B C D E F G H I J K L M 50DH VR 50AXU 75U 1200 20 38 15 44 16 50 5 00 9 00 26 81 58 33 16 44 8 44 8 50 5 25 17 00 5 88 A I F E D D B G C J K L H M ...

Page 6: ...Replacement Circuit Breaker Table 3 50DH VR 50DH VR 50XU 75ARU Rear Racking Device Shown Circuit Breaker Type Existing Circuit Breaker Rated Continuous Current at 60 Hz Amps A B C D E F G H I J 50DH VR 50XU 75ARU 1200 5 00 31 53 44 00 9 00 26 62 21 81 17 26 8 25 23 50 58 01 A A B C D E F G H I J ...

Page 7: ... shock leading to death severe personnel injury or property damage Do not work on a circuit breaker with the secondary test coupler engaged Failure to disconnect the test coupler could result in an electrical shock leading to death personnel injury or property damage Do not work on a closed circuit breaker or a circuit breaker with closing springs charged The closing spring should be discharged an...

Page 8: ...d as part of the vacuum replacement circuit breaker Secondary Connection Block Extension Cable The extension cable can be used to connect the circuit breaker to a test cabinet or to the switchgear cell s secondary receptacle block so that the circuit breaker can be electrically operated while not installed in the switchgear cell This extension cable is the same one provided with the original Westi...

Page 9: ...red indicator Push the manual trip button The circuit breaker will trip as shown by the circuit breaker contacts open green indicator After completing this initial check leave the closing springs discharged and circuit breaker contacts open Outdoor storage is NOT recommended If unavoidable the outdoor location must be well drained and a temporary shelter from sun rain snow corrosive fumes dust dir...

Page 10: ...H VR 50DH VR 50AXU 75U Front Racking Shown Front External View 1 Manual Charging Handle 5 Racking Mechanism Arm 9 Push To Close Button 2 Contact Status Indicator 6 Secondary Disconnect Slide 10 Operation Counter 3 Push To Open Button 7 Tow Hitch 11 Racking Access 4 Position Indicator 8 Closing Spring Status Indicator 12 Lock Out Flag 1 2 3 5 4 6 7 8 9 10 5 11 12 ...

Page 11: ...AXU 50XU 75U 75ARU 600 1200A Replacement Circuit Breaker 1 2 3 4 5 Figure 3 3 b Rear External View of 50DH VR 50DH VR 50AXU 75U Front Racking Shown Rear External View 1 Primary Disconnect 3 Anti Rotation Bracket 5 Secondary Disconnect 2 Shutter Roller 4 Ground Contact ...

Page 12: ...DH VR 50DH VR 50XU 75ARU Rear Racking Shown Front External View 1 Manual Charging Handle 5 Racking Mechanism Arm 9 Push To Close Button 2 Contact Status Indicator 6 Secondary Disconnect Slide 10 Operation Counter 3 Push To Open Button 7 Tow Hitch 11 Racking Access 4 Position Indicator 8 Closing Spring Status Indicator 12 Lock Out Flag 1 2 3 4 5 6 7 8 9 5 10 11 ...

Page 13: ...75ARU 600 1200A Replacement Circuit Breaker Figure 3 3 d Rear External View of 50DH VR 50DH VR 50XU 75ARU Rear Racking Shown 2 1 4 3 5 3 1 6 Rear External View 1 Shutter Roller 3 Racking Mechanism Arm 5 Ground Contact 2 Primary Disconnect 4 Interlock Linkage 6 Secondary Disconnect ...

Page 14: ...over time with Eaton vacuum interrupters A contact erosion indicator mark is located on the moving stem of the interrupter Figure 6 1 and 6 2 In order to determine if the contacts have eroded to the extent that the interrupter must be replaced close the circuit breaker and observe the erosion mark placed on each moving stem from the rear of the circuit breaker If the mark on the interrupter stem i...

Page 15: ...e cell In addition to the original interlocks VR Series circuit breakers provide an anti close interlock at the ends of the conductors provide means for connecting and disconnecting the circuit breaker to the bus terminals in the switchgear compartment 4 5 STORED ENERGY MECHANISM The spring type stored energy operating mechanism is mounted on the circuit breaker frame and in the front of the circu...

Page 16: ...16 Instruction Book IB182012EN March 2017 www eaton com 50DH VR 50AXU 50XU 75U 75ARU 600 1200A Replacement Circuit Breaker Figure 4 2 Typical AC DC Schematic ...

Page 17: ...e operated Position B Figure 4 4 As the circuit breaker is pushed into the switchgear it will reach a mechanical stop This is the DISCONNECT position and the circuit breaker is still in the trip free state and cannot be operated Although it is possible to engage the secondary disconnect block in this position it SHOULD NOT BE engaged at this time Position C The racking handle is inserted on the ra...

Page 18: ...y disconnect will disengage automatically The position mode indicator will change from TEST OPERATE to TRIP FREE Figure 4 6 Front Racking Connect Position F Figure 4 7 Rear Racking Disconnect Position B The circuit breaker is in a non operable mode and will go through a trip free operation if an attempt to close it were made Position H Continue racking in the counterclockwise direction and the shu...

Page 19: ...ll engage the trip release mechanism The circuit breaker will not be able to mechanically close in this position As you continue to advance the circuit breaker into the switchgear the primary voltage source shutters will open allowing the circuit breaker stabs to engage with the source Position F Figure 4 9 Continue the clockwise rotation of the racking handle until a mechanical stop is reached Th...

Page 20: ...y manually pulling on the handle located immediately below the position mode indicator The racking system is in the DISCONNECT orientation The circuit breaker is in a trip free status and in a non operable state in the withdrawn position 4 14 MISCELLANEOUS ITEMS 4 14 1 GROUNDING CONTACT The grounding contact is an assembly of spring loaded fingers which ground the circuit breaker frame static grou...

Page 21: ...ts are completely de energized 2 Protect all primary disconnects and secondary disconnects and terminal boards from the metallic dust that will be generated during the cutting process This must be done with drop cloths or tarps that are sealed along their edges with duct tape or equivalent means 3 Refer to Figure 5 2 for dimensional information on the Front Racked circuit breakers 4 With a suitabl...

Page 22: ...5U 75ARU 600 1200A Replacement Circuit Breaker Figure 5 2 Completed Cell Modification Front Racking 25 500 20 88 CUTOUT 8 375 50 CUTOUT 50 CUTOUT MIDDLE POST SHOWN CELL FLOOR ANGLE 25 500 20 88 CUTOUT 1 1 1 1 16 75 7 875 7 875 15 750 REF OPENING CELL FRONT SHOWING MODIFICATION ...

Page 23: ...ON LOCKNUT Steel Mild 70220EPN18 2 9 3 8 SHIM Steel Mild 3088A361 4 10 HDW 3 8 EXTRA WIDE FLAT WASHER Steel Mild 70500BD32B 4 11 HDW 1 4 20 X 1 HEX HD CAP SCRW Steel Mild 70100EG01S 6 12 HDW 1 4 20 HEX NUT Steel Mild 70210BK616 6 13 HDW 1 4 LOCK WASHER Steel Mild 70510CV10M 6 14 HDW 3 8 16 NYLON LOCKNUT Steel Mild 70220EPN1A 2 SYM ITEM DEFINER DESCRIPTION MATERIAL PART N0 REV QTY 3 9 9 6 10 10 14 ...

Page 24: ...NG 16 875 OPENING AFTER CUTTING 22 00 CUTOUT DEPTH 563 563 TOP OF CHANNEL 4 800 20 000 17 750 17 875 281 1 000 15 75 OPENING REF 8 875 8 938 1 1 MIDDLE POST IN CELL MIDDLE POST IN CELL DETAIL SHOWING HOLE LAYOUT DETAIL SHOWING CUT OUT MIDDLE POST IN CELL TOP OF CHANNEL MIDDLE POST IN CELL Figure 5 4 Completed Cell Modification Rear Racking ...

Page 25: ...aw with a metal cutting blade remove the metal within the outline A grinder may be needed to clean up the cuts after grinding 8 With an industrial vacuum cleaner remove all of the metallic dust from inside the cell Wipe down any areas that may trap these metallic particles taking care not to be cut by any sharp edges or metal burrs Gray primer paint may be optionally applied to the exposed metal s...

Page 26: ...m interface with the circuit breaker trip linkage f To rack the circuit breaker further into the cell rotate the racking handle clockwise In approximately 1 1 2 clockwise turns of the racking handle the position indicator Figure Set 3 3 will reflect TEST OPERATE In the TEST position the circuit breaker can be closed and tripped manually and electrically thus allowing maintenance test or checks To ...

Page 27: ...e mode and will be prevented from closing if any attempt to close it is made in the intermediate position The shutters will close after the main primary disconnects have cleared isolating the circuit breaker from the power source Continue racking out until the position mode indicator shows TEST OPERATE and the shutter indicator shows closed The circuit breaker is in the TEST position and the trip ...

Page 28: ...rging Motor Disconnected Withstand 1125V 60Hz For 1 Minute Hipot Tester Clean And Retest Or Replace 2 Power Element Vacuum Interrupters Contact Erosion Visibility Of Mark Visual Close The Circuit Breaker And Look For Green Mark On Moving Stem From The Rear Of The Circuit Breaker See Figure 6 1 and 6 2 If Mark Is Not Visible Replace Interrupter Assembly Contact Wipe Visible Visual Figure 6 3 and 6 ...

Page 29: ...nter shield of vacuum interrupters To avoid any ambiguity in the AC high potential test due to leakage or displacement capacitive current the test unit should have sufficient volt ampere capacity It is recommended that the equipment be capable of delivering 25 milliamperes for one minute The current delivery capability of 25 mA AC applies when all three VI s are tested in parallel If individual VI...

Page 30: ... Wipe Inspection Area Figure 6 3 Satisfactory Contact Wipe Condition with Circuit Breaker Closed Figure 6 4 Unsatisfactory Contact Wipe Condition with Circuit Breaker Closed Drive Insulator Top Inspection Area Top Surface Drive Insulator Wipe Indicator Below Top Surface Top Surface Drive Insulator Wipe Indicator Flush with Top Surface Circuit Breaker Rated Maximum Voltage Test Voltage 5 kV 15 kV t...

Page 31: ...more than 200 as stated in IEEE C37 09 Factory test levels are recorded on the circuit breaker test form which is included with the breaker If measurements exceeds 200 contact the manufacturer Resistance conversion for Temperature Rconversion RFactory 1 TField TFactory r Rconversion Resistance correction for temperature based from the factory resistance measurement RFactory Resistance measurement ...

Page 32: ...pen Or Burned Motor Cut Off Contacts Open Or Burned Trip Coil Assembly Clapper Fails To Reset Closing Sound But No Close Pole Shaft Not Open Fully Trip Latch Reset Spring Damaged Or Missing Trip Bar D Shaft Fail To Remain Reset Trip Latch Hatchet Fails To Remain Reset Trip Floor Tripper Fails To Remain Reset Close Latch Binding Close Latch Roller Binding Trip Circuit Energized UNDESIRABLY CLOSES C...

Page 33: ...g record it is a good practice to stock one set of control components for every six circuit breakers of the same control voltage This quantity should be adjusted with time and frequency of operation of the circuit breakers 7 2 ORDERING INSTRUCTIONS a The style numbers in Table 7 1 should be sufficient to purchase control components for most applications Some circuit breakers have special control s...

Page 34: ...ulevard Cleveland OH 44122 United States Eaton com 2017 Eaton All Rights Reserved Printed in USA Publication No IB182012EN March 2017 Eaton is a registered trademark All trademarks are property of their respective owners ...

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