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Instruction Book IB182942EN May 2019 www.eaton.com
DST-2-VR
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VR-Series
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Replacement Circuit Breaker
SECTION 5: INSPECTION & INSTALLATION
WARNING
BEFORE PLACING THE CIRCUIT BREAKER IN SERVICE, CAREFULLY FOLLOW
THE INSTALLATION PROCEDURE BELOW AND THE SAFE PRACTICES SET
FORTH IN SECTION 2. NOT FOLLOWING THE PROCEDURE MAY RESULT IN
INCORRECT CIRCUIT BREAKER OPERATION LEADING TO DEATH, BODILY
INJURY, AND PROPERTY DAMAGE.
When the circuit breaker is first commissioned into service and each
time the circuit breaker is returned to service, it should be carefully
examined and checked to make sure it is operating correctly.
5.1 EXAMINATION FOR DAMAGE
Examine the circuit breaker for loose or obviously damaged parts.
Never attempt to install nor operate a damaged circuit breaker.
5.1.1 NAMEPLATE VERIFICATION
Verify the information on the new VR-Series
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nameplate matches
the information on the purchase order. If any discrepancies exist,
notify Eaton’s Electrical Services & Systems for resolution prior to
proceeding.
WARNING
ALWAYS DE-ENERGIZE/ISOLATE THE POWER SOURCE FEEDING THE
CIRCUIT BREAKERS/SWITCHGEAR AND LOCK-OUT/TAG-OUT THE POWER
SOURCE PRIOR TO INSERTION OR REMOVAL OF ANY CIRCUIT BREAKER.
NEVER ATTEMPT TO MAINTAIN OR MODIFY A CIRCUIT BREAKER WHILE
INSERTED IN A SWITCHGEAR CELL STRUCTURE. ALWAYS REMOVE
THE CIRCUIT BREAKER AND MOVE IT TO A SUITABLE AREA FOR
MAINTENANCE OR REPAIR.
FOLLOW ALL LOCKOUT AND TAG-OUT REQUIREMENTS OF THE NATIONAL
ELECTRIC CODE, OSHA AND ANY OTHER APPLICABLE LOCAL CODES,
REGULATIONS AND PROCEDURES.
5.2
SURE CLOSE
MECHANISM ADJUSTMENT
WARNING
FOR ALL TYPE CIRCUIT BREAKER HOUSINGS EQUIPPED WITH MECHANISM
OPERATED CELL (MOC) SWITCHES, THE STEPS OUTLINED IN THIS SECTION
MUST BE PERFORMED BEFORE INSTALLING A REPLACEMENT VR-SERIES
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CIRCUIT BREAKER. FAILURE TO COMPLY COULD CAUSE SEVERE PERSONAL
INJURY, DEATH, EQUIPMENT DAMAGE AND/OR IMPROPER OPERATION
All type DST-2-VR
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circuit breakers with MOC operators utilize the
SURE CLOSE
mechanism to control kinetic energy transfer and
closely mimic the dynamics and velocities of older circuit breakers. It
is imperative that this mechanism be adjusted to compensate for the
force of the MOC switch mounted in the cell.
The circuit breaker
SURE CLOSE
MOC operator is factory adjusted
to a force of 37-52 lbf. This force has been proven to successfully
operate a well-maintained Federal Pacific 8-9 stage MOC switch
provided it does not have excessive pitting or arcing on its contacts.
The parameters for the existing MOC switch should be verified and
adjustments made to the cell switch mounting location. Do not
attempt to insert or operate a DST-2-VR
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replacement circuit breaker
in a cell containing an MOC until after the switch has been properly
adjusted.
WARNING
MEASUREMENTS AND ADJUSTMENTS SHOULD NEVER BE ATTEMPTED
IN AN ENERGIZED STRUCTURE. IF THE STRUCTURE CANNOT BE
DE-ENERGIZED, THEN PROPER PERSONAL PROTECTIVE EQUIPMENT PER
NFPA 70E MUST BE WORN AT ALL TIMES WHILE GATHERING MOC SWITCH
DATA, ADJUSTING OR SERVICING THE MOC SWITCH. FAILURE TO COMPLY
WITH THIS WARNING COULD CAUSE SEVERE PERSONAL INJURY, DEATH,
EQUIPMENT DAMAGE AND/OR IMPROPER OPERATION.
Locate the cell mounted MOC. Two functional versions of the MOC
interface are known to exist. One operates the MOC switch in the
connected position only and the other will operate in either the
“TEST” or “CONNECTED” positions. Figures 5.3.a shows the MOC
switch that can operate in the “TEST” or “CONNECTED” positions.
To insure the proper operation of the
SURE CLOSE
mechanism, the
MOC assembly should be cleaned and inspected for worn parts,
lubricated and properly secured in the cell before proceeding. A
spring force gauge should be used to measure the forces needed
to move the switch to the fully closed position prior to inserting the
circuit breaker.
Sttp 1e:
Attach a spring force gauge to the round operating rod as
shown (Figure 5.3.c) and pull vertically until the switch contacts
have all changed state. Do not “over-pull” on the gauge. Measure
and record the force. It should be approximately 27-32 lbf for a
properly maintained and adjusted Federal Pacific MOC switch
with 8-9 stages. The force will be higher for switches with more
stages or if improperly maintained.
Sttp 2e:
Place the circuit breaker at a safe distance from the cell
structure and on a level surface. If the cell structure is energized,
be sure the circuit breaker is beyond the Arc Flash Boundary.
Chock the wells to prevent movement. Use the maintenance tool
to charge the stored energy mechanism and manually press the
“PRESS TO CLOSE” device to close the circuit breaker.
Sttp 3e:
Attach the spring force gauge as shown in Figure 5.14
and pull down vertically (approximately .125 - .25”) to measure
the
SURE CLOSE
MOC operator force. It should measure
between 37-52 lbf. This provides a minimum margin/differential of
approximately 10 lbf to operate the MOC switch. If the differential
force between the
SURE CLOSE
MOC operator and the MOC
switch is less than 10 lbf, then the
SURE CLOSE
MOC operator
force should be increased to obtain a 10 lbf differential between
the force measure in the cell and the output force of the circuit
breaker with the circuit breaker being the greater of the two
forces. Proceed with the following steps to increase the circuit
breaker
SURE CLOSE
MOC operator force:
Sttp 4e:
Open the circuit breaker by depressing the “PUSH TO
OPEN” operator. Locate the
SURE CLOSE
MOC drive spring
(Figure 3.4). It is located in the lower left portion of the circuit
Figurt 5.1.
SURE CLOSE
Spring Comprtssion Sttting
