g
MicroVersaTrip Plus™ and
MicroVersaTrip PM™ Conversion Kits
for I-T-E®/ABB® Types K-3000, K-3000S, K4000,
and K-4000S Low-Voltage Power Circuit
Breakers
INTRODUCTION
GE Conversion Kits are designed for upgrading
existing I-T-E®/ABB® low-voltage power circuit
breakers, rather than replacing the entire breaker.
The Conversion Kits include MicroVersaTrip Plus™
or MicroVersaTrip PM™ Trip Units, the latest technological advance in GE trip systems.
MicroVersaTrip Plus and MicroVersaTrip PM Conversion Kits are designed and tested to conform to ANSI
Standard C37.59, allowing the retrofitter to properly
install the kit and acceptance test the breaker.
This publication covers installation of
MicroVersaTrip Plus and MicroVersaTrip PM Conversion Kits on I-T-E/ABB Types K-3000, K-3000S, K4000, and K-4000S low-voltage power circuit breakers. Each Conversion Kit contains all the components
needed to convert from the existing trip system.
DEH–133B Installation Instructions
TABLE OF CONTENTS
SECTION 1. GENERAL INFORMATION.......................................................................................................4
SECTION 2. BEFORE INSTALLATION..........................................................................................................4
SECTION 3. BACK FRAME BREAKER CONVERSION
Electromechanical Trip Device Removal (Types K-3000 and K-4000 only) ................................... 5
Installing New Phase Base Moldings (K-3000 and K-4000 only)...................................................8
Solid State Trip Device Removal (K-3000S and K-4000S only)...................................................10
Installing the Phase Sensors (All Models) ...................................................................................12
SECTION 4. FRONT FRAME CONVERSION
Installing the Trip Paddle..............................................................................................................13
Installing the Flux Shifter .............................................................................................................. 14
Adjusting the Flux Shifter.............................................................................................................16
Installing the Trip Unit Wiring Harness ........................................................................................ 17
Installing the Trip Unit Bracket..................................................................................................... 19
Installing the Wiring Harness .......................................................................................................19
SECTION 5. INSTALLING THE TRIP UNIT................................................................................................21
SECTION 6. FOUR-WIRE GROUND FAULT OPTION.............................................................................22
SECTION 7. TESTING AND TROUBLE-SHOOTING
Testing........................................................................................................................................... 23
Trouble-Shooting..........................................................................................................................23
Nuisance Tripping on Ground Fault-Equipped Breakers................................................23
LIST OF FIGURES
1. I-T-E/ ABB breaker before conversion. .................................................................................................... 5
2. Escutcheon removal................................................................................................................................. 5
3. Arc chute removal.................................................................................................................................... 5
4. Auxiliary switch mounting plate removal............................................................................................... 6
5. Removing the phase barrier support rod................................................................................................ 6
6. Loosening the locking bolt on the main contact closing arm jack shaft. .............................................. 6
7. Removing the adjusting screw from the jack shaft clevis...................................................................... 6
8. Removing the phase barriers. ................................................................................................................. 7
9. Removing the draw-out primary contact fingers.................................................................................... 7
10. Removing the pole assembly.................................................................................................................. 7
11. Removing the contact assembly mounting bolts................................................................................... 8
12. Disassembled pole unit. .......................................................................................................................... 8
13. Installing the contact mounting plate...................................................................................................... 8
14. Converted pole assembly. ....................................................................................................................... 8
15. Removing the existing trip paddle, as seen from the rear..................................................................... 9
16. X washer installed on a draw-out contact finger assembly................................................................... 9
17. Escutcheon removal............................................................................................................................... 10
18. Arc chute removal.................................................................................................................................. 10
19. Auxiliary switch mounting plate removal............................................................................................. 10
20. Draw-out primary contact finger assembly removal............................................................................ 11
21. Removing the shunt mounting bolts. ................................................................................................... 11
22. K-3000S with CTs and shunts removed. ............................................................................................... 11
23. Installing the CT spacers. ....................................................................................................................... 12
24. Installing the phase sensors.................................................................................................................. 12
25. Installing the CT retaining plates. .......................................................................................................... 12
26. Installing the trip paddle, as viewed from the rear of the breaker....................................................... 13
27. Removing the bolt and nut from the right-pole closing arm assembly. ............................................. 14
28. Reset stud installed on the right-pole closing arm............................................................................... 14
29. Flux shifter mounting holes in the right side frame............................................................................. 14
30. Flux shifter installed. .............................................................................................................................. 15
31. Installation of the flux shifter reset arm................................................................................................ 15
32. Attaching the X washer to secure the flux shifter reset arm. ............................................................... 15
33. Adjusting the flux shifter, viewed from the top of the breaker. ........................................................... 16
34. 36-pin trip unit connector....................................................................................................................... 17
35. 36-pin connector adapter bracket.......................................................................................................... 17
36. Adapter bracket locking tabs................................................................................................................. 17
37. Installing the push nuts onto the guide pins........................................................................................ 18
38. Locking tabs on mounting plate............................................................................................................ 18
39. Installing the trip unit bracket. ............................................................................................................... 19
40. Flux shifter wiring harness leads........................................................................................................... 19
41. CT wiring harness leads......................................................................................................................... 19
42. Caution label to be applied to the breaker and compartment door. ................................................... 20
43. Unused communications and neutral CT wiring tied off. .................................................................... 20
44. Installing the trip unit on its mounting plate. ....................................................................................... 21
45. Neutral sensor outline for I-T-E® K-3000, K-3000S, K-4000, and K-4000S breakers ............................ 22
46. Cabling diagram for MicroVersaTrip Plus™ and MicroVersaTrip PM™ trip units with
ground fault on four-wire loads ............................................................................................................ 25
SECTION 1. GENERAL INFORMATION
SECTION 2. BEFORE INSTALLATION
GE Conversion Kit installation is straightforward, but
does require careful workmanship and attention to
these instructions. Familiarity with the breaker is
highly desirable. The general approach is to first
remove the existing trip devices from the breaker,
then install the MicroVersaTrip Plus or MicroVersaTrip PM kit components. Following this procedure,
the converted breaker is performance tested before it
is returned to service.
The majority of trip unit kit installations do not
require any customized assembly work. However,
some conversions may involve unusual mounting
conditions or accessory combinations that require
minor modifications and/or relocation of components. In most instances, this supplementary work
can be done on site.
In preparation for the conversion, the installer should
verify that the appropriate current sensors and trip
unit have been furnished. Whenever a ground-fault
trip element is installed on a breaker with a four-wire
system, an associated neutral sensor (CT) is required
for separate mounting in the equipment.
Ensure that retrofitted breakers are applied within
their short-circuit ratings. For example, if the previous trip unit provided long-time instantaneous protection, the short-time rating of the MicroVersaTrip
Plus or MicroVersaTrip PM Trip Unit will govern the
application.
As a service-related consideration, the installation of
a MicroVersaTrip Plus or MicroVersaTrip PM kit provides an excellent opportunity to perform normal
maintenance on the breaker. Such procedures are
described in the installation and maintenance manuals supplied with the breaker and equipment.
Before starting any work, turn off and lock out all
power sources leading to the breaker, both primary
and secondary. Remove the breaker to a clean, welllighted work area.
WARNING: Low-voltage power circuit breakers use
high-speed, stored-energy spring operating mechanisms. The breakers and their enclosures contain
interlocks and safety features intended to provide
safe, proper operating sequences. For maximum
personnel protection during installation, operation,
and maintenance of these breakers, the following
procedures must be followed. Failure to follow
these procedures may result in personal injury or
property damage.
• Only qualified persons, as defined in the
National Electrical Code, who are familiar with
the installation and maintenance of low-voltage
power circuit breakers and switchgear
assemblies, should perform any work on these
breakers.
• Completely read and understand all instructions
before attempting any breaker installation,
operation, maintenance, or modification.
• Turn off and lock out the power source feeding
the breaker before attempting any installation,
maintenance, or modification. Follow all lockout and tag-out rules of the National Electrical
Code and all other applicable codes.
• Do not work on a closed breaker or a breaker
with the closing springs charged. Trip the
breaker OPEN and be sure the stored-energy
springs are discharged, thus removing the possibility that the breaker may trip open or the
closing springs discharge and cause injury.
• Trip the breaker OPEN, then remove the breaker
to a well-lighted work area before beginning
work.
• Do not perform any maintenance that includes
breaker charging, closing, tripping, or any other
function that could cause significant movement
of a draw-out breaker while it is on the draw-out
extension rails.
• Do not leave the breaker in an intermediate
position in the switchgear compartment. Always
leave it in the connected, test, or disconnected
position. Failure to do so could lead to improper
positioning of the breaker and flashback.
WARNING: Before installing the conversion kit, turn
the breaker OFF, disconnect it from all voltage
sources, and discharge the closing springs.
SECTION 3. BACK FRAME BREAKER
CONVERSION
The back frame conversion of an I-T-E/ABB type
K-3000, K-3000S, K-4000, or K-4000S circuit breaker,
as shown in Figure 1, consists of the following steps:
1. Removing the existing electromechanical or solid
state trip devices.
2. Installing new phase base moldings (K-3000 and
K-4000 only).
3. Installation of the phase sensor (CT) assemblies.
Following are detailed descriptions of these steps. Be
sure to remove the breaker to a clean, will-lighted
work bench and place it in the upright position, so
that the front and back are easily accessible.
Electromechanical Trip Device Removal
(Types K-3000 and K-4000 only)
1. Remove the seven mounting screws securing the
front escutcheon to the breaker, as shown in
Figure 2, retaining all the hardware. Lift off the
escutcheon.
2. Loosen the two retaining bolts securing the arc
chutes, as shown in Figure 3. Lift out the arc
chute assemblies from each pole.
Figure 1. I-T-E/ ABB breaker before conversion.
Figure 2. Escutcheon removal.
Figure 3. Arc chute removal.
3. Remove the nine mounting screws securing the
auxiliary switch mounting plate to the breaker, as
shown in Figure 4. Remove the mounting plate.
CAUTION: If the breaker contains auxiliary switches,
the auxiliary switch mounting plate must be
temporarily supported to the side in order to
prevent accidental damage to the breaker’s integral
wiring harness.
4. Remove the two retaining clips securing the
phase barrier support rod, then slide the rod out
through the side frame of the breaker, as shown
in Figure 5. Retain the rod and clips.
5. Loosen the locking bolt on the jack shaft of the
main contact closing arm, as shown in Figure 6.
Remove the adjustment screw from the clevis, as
shown in Figure 7.
Figure 5. Removing the phase barrier support rod.
Figure 4. Auxiliary switch mounting plate removal.
Figure 6. Loosening the locking bolt on the main contact closing
arm jack shaft.
Figure 7. Removing the adjusting screw from the jack shaft
clevis.
6. To remove the phase barriers on each phase,
push the moving contact assembly and the
adjustment screw toward the rear of the breaker,
then pull the phase barrier up and to the front, as
shown in Figure 8.
7. Remove the retaining clip from the center
mounting post of each line and load draw-out
primary contact finger assembly, as shown in
Figure 9, then remove the fingers. Be sure to save
the existing flat washer from each assembly for
reuse, but discard the retaining clip.
8. Remove the four hex-head bolts securing the
pole assembly to the breaker, as shown in Figure
10. Tilt the pole assembly forward and lift
upward to remove it from the breaker. Be sure to
save all hardware.
CAUTION: The pole assembly is heavy and awkward. Take care not to damage the assembly or the
breaker’s common trip shaft while removing the
pole assembly.
Figure 8. Removing the phase barriers.
Figure 9. Removing the draw-out primary contact fingers.
Insulating
Strips
Figure 10. Removing the pole assembly.
Insulating
Strips
9. The stationary and moving contact assemblies
must be separated from the original molded base
assembly. Remove the eight hex-head mounting
bolts, as shown in Figure 11. Retain the four
mounting bolts from the stationary contact
assembly. Discard the four bolts for the moving
contact assembly and the original base molding
and electromechanical trip device. Figure 12
shows the disassembled pole unit.
10. If the existing insulating strips, shown in Figure
10, are made of fiber board, they must be
replaced. Remove and discard the old insulating
strips and replace with the new, slide-on
insulators provided in the kit.
Installing New Phase Base Moldings (K3000 and K-4000 only)
1. Mount the stationary contact assembly to the
new phase base molding provided using the
hardware removed earlier, as shown in Figure 14.
2. Attach the contact mounting plate to the moving
contact assembly with the two 5/16-18 x 3/4" flathead bolts provided, as shown in Figure 13. Prick
the contact mounting plate on either side of each
mounting bolt head with a center punch to lock
the mounting bolts in place. Repeat this step for
each phase of the breaker.
3. Install the moving contact assembly and mounting plate on the phase base molding with the two
5
/16-18 x 13/4" hex-head bolts, lock washers, and
flat washers provided, as shown in Figure 14.
Repeat this step for each phase of the breaker.
4. Attach the mounting plate to the phase base
molding with the two 5/16-18 x 13/4" hex-head
bolts, lock washers, flat washers, and hex nuts
provided, as shown in Figure 14. Repeat this step
for each phase of the breaker.
Figure 11. Removing the contact assembly mounting bolts.
Figure 12. Disassembled pole unit.
Figure 13. Installing the contact mounting plate.
Figure 14. Converted pole assembly.
5. Remove the two mounting screws securing the
trip paddle for the right pole assembly to the
common trip shaft, as shown in Figure 15. Discard the trip paddle and screws.
NOTE: Figure 15 shows the trip paddle from the
rear, with the right pole assembly removed from
the breaker.
WARNING: The mounting hardware used to reassemble the breaker’s pole assemblies must be correctly tightened for proper operation. Refer to the
original manufacturer’s operating and maintenance
manuals before performing the following step.
Failure to properly tighten the mounting hardware
may result in breaker failure, property damage,
and/or personal injury.
6. Reassemble each pole assembly to the breaker
by following steps 4 to 8 in Electromechanical
Trip Device Removal above in reverse order. Use
the X washer provided to reinstall the line-side
draw-out primary contact fingers, as shown in
Figure 16.
CAUTION: Seven X washers are supplied with the
conversion kit. One of the X washers in smaller than
the rest. Use the six larger washers for installing the
draw-out primary contact fingers.
7. Adjust the breaker’s contact wipe and gap settings per the original manufacturer’s operating
and maintenance manuals.
WARNING: In order to ensure proper operation of
the breaker, it is crucial that the breaker’s contact
wipe and gap settings be adjusted per the original
manufacturer’s operating and maintenance manuals. Failure to properly adjust the contact assemblies will result in breaker failure, property damage,
and/or personal injury.
8. Reattach the three arc chutes to the breaker.
Continue back frame conversion with installation of
the phase sensors (CTs).
Figure 15. Removing the existing trip paddle, as seen from the
rear.
Figure 16. X washer installed on a draw-out contact finger
assembly.
Solid State Trip Device Removal (K-3000S
and K-4000S only)
1. Remove the seven mounting screws from the
front escutcheon, as shown in Figure 17, and lift
off the escutcheon. Retain all the mounting
hardware.
2. Loosen the two retaining bolts securing the arc
chutes, as shown in Figure 18. Lift out the arc
chute assemblies from each pole.
3. Remove the nine mounting screws securing the
auxiliary switch mounting plate to the breaker, as
shown in Figure 19. Remove the mounting plate.
CAUTION: If the breaker contains auxiliary switches,
the auxiliary switch mounting plate must be
temporarily supported to the side in order to
prevent accidental damage to the breaker’s integral
wiring harness.
Figure 17. Escutcheon removal.
Figure 18. Arc chute removal.
Figure 19. Auxiliary switch mounting plate removal.
4. Remove the retaining clip from the center
mounting post of each line and load draw-out
primary contact finger assembly, as shown in
Figure 20, then remove the fingers. Be sure to
save the existing flat washer from each assembly
for reuse, but discard the retaining clip.
5. Remove the three mounting screws on the existing current sensor triangular retaining plate on
each breaker pole. Remove and discard the
plates.
6. Remove and discard the existing current sensors,
trip actuator, trip device, trip device mounting
bracket, and CT wire harness from the breaker.
Refer to the original manufacturer’s operating
and maintenance manuals for details on
performing this step.
7. Remove the two mounting bolts on the existing
shunt on each pole of the breaker, as shown in
Figure 21, then remove and discard the shunt.
Replace the mounting hardware with the two
5
/16-18 x 13/4" hex-head bolts, lock washers, and
flat washers provided, as shown in Figure 22.
Continue back frame conversion with installation of
the phase sensors (CTs).
Figure 21. Removing the shunt mounting bolts.
Figure 20. Draw-out primary contact finger assembly removal.
Figure 22. K-3000S with CTs and shunts removed.
Installing the Phase Sensors (All Models)
1. Slide the CT spacer over each load-side copper
stab of the breaker, as illustrated in Figure 23.
2. Slide the phase sensors over each of the loadside copper stabs. Be sure that each CT’s wire
leads are facing toward the front of the breaker
and are fed through the pole assembly under the
moving contact mounting plate, as shown in
Figure 24.
3. Mount the CT retaining plate to each phase base
molding using the two #10-32 x 1/2" screws, lock
washers, and flat washers provided, as shown in
Figure 25. Be sure that the alignment stud on the
phase sensor inserts into the mating hole on the
CT retaining plate.
WARNING: In order to ensure the proper operation
of the phase sensors, it is crucial that the alignment
stud on each phase sensor aligns with the hole in
the CT retaining plate. Failure to properly install the
CTs may result in inadequate protection from the
trip unit.
4. Reattach the load-side draw-out primary contact
finger assemblies to the breaker using the provided X washers, as shown in Figure 16.
Figure 24. Installing the phase sensors.
Figure 23. Installing the CT spacers.
Figure 25. Installing the CT retaining plates.
SECTION 4. FRONT FRAME
CONVERSION
The front frame conversion of an I-T-E/ABB type
K-3000, K-3000S, K-4000, or K-4000S circuit breaker
consists of the following steps:
1. Installation of the trip paddle.
2. Installation of the flux shifter.
3. Adjustment of the flux shifter.
4. Installation of the trip unit bracket assembly.
5. Installation of the wiring harness.
Installing the Trip Paddle
The trip paddle is installed on the right end of the
breaker’s common trip shaft, as shown in Figure 26.
1. Align the trip paddle with the mounting holes
located approximately 5/16 and 11/16" from the
right end of the trip shaft.
2. Attach the trip paddle to the breaker’s trip shaft
using the two #8-32 x 11/8" screws, lock washers,
and nuts provided. Note that the mounting flange
of the trip paddle must be on top of the trip shaft
and face towards the outside of the breaker.
NOTE: Figure 26 shows the trip paddle installation
from the rear of the breaker with the right pole
assembly removed from the breaker.
Figure 26. Installing the trip paddle, as viewed from the rear of the
breaker.
Installing the Flux Shifter
Holes
1. Remove and discard the existing hex-head bolt
and locking hex nut from the right-pole closing
arm, as shown in Figure 27.
2. Attach the reset stud to the right-pole closing
arm using the 5/16-18 locking hex nut provided,
as shown in Figure 28. The hex-shaped end of
the reset stud should face toward the right side
of the breaker.
3. Mount the flux shifter assembly to the inside of
the breaker’s right side frame using the existing
holes, shown in Figure 29, and the two 1/4-20 x
3
/4" screws, lock washers, and hex nuts provided,
as shown in Figure 30.
CAUTION: If the breaker contains a positive interlock assembly on the right side frame, the mounting eye bolt of the positive interlock’s spring must
be removed to allow installation of the flux shifter
assembly. After installation of the flux shifter, the
mounting eye bolt may be reinstalled in its original
location.
Reset
Stud
Figure 28. Reset stud installed on the right-pole closing arm.
Figure 27. Removing the bolt and nut from the right-pole closing
arm assembly.
Flux Shifter
Mounting
Figure 29. Flux shifter mounting holes in the right side frame.
4. Connect the flux shifter reset arm to the reset
stud using the X washer provided, as shown in
Figures 31 and 32.
CAUTION: Seven X washers are supplied with the
kit. One of the washers is smaller than the rest. The
smaller X washer is used for installing the flux
shifter reset arm.
NOTE: Figure 30 shows the installed flux shifter
assembly from the rear with the right pole assembly removed from the breaker.
Figure 31. Installation of the flux shifter reset arm.
Reset
Arm
Figure 30. Flux shifter installed.
Figure 32. Attaching the X washer to secure the flux shifter reset
arm.
Adjusting the Flux Shifter
When the trip paddle and flux shifter have been
installed, the following adjustments must be made:
1. With the breaker in the CLOSED position, the gap
between the trip paddle and the flux shifter
adjustment screw, as shown in Figure 33, should
be approximately 1/16". It may be helpful to
gauge the air gap with a 1/16"-diameter rod (not
provided with the conversion kit). Make any
adjustments with the breaker OPEN, then CLOSE
the breaker and recheck the gap.
Gap
Adjustment
Screw
Trip
Paddle
WARNING: Extreme caution must be used when
working on a CLOSED breaker. Do not reach your
hands into the breaker’s operating mechanism or
contact area while adjusting the flux shifter. Failure
to adhere to these precautions may result in serious
personal injury.
2. Optional Test – The flux shifter assembly may be
tested by closing the breaker and applying a 9
Vdc power source to the flux shifter leads. The
red wire (pin #2) is the positive lead, while the
white wire (pin #1) is the negative lead, The
breaker should open.
CAUTION: The 9 Vdc power source should only be
applied momentarily. Prolonged application of the
dc power source can damage the flux shifter.
Figure 33. Adjusting the flux shifter, viewed from the top of the
breaker.
Installing the Trip Unit Wiring Harness
The wiring harness includes a 36-pin connector,
shown in Figure 34, that must be assembled and
installed onto the trip unit mounting plate before the
trip unit can be installed. Use the following procedure to install the trip unit wiring harness to the
mounting plate.
CAUTION: The adapter bracket must be installed
onto the trip unit 36-pin connector and trip unit
mounting plate as described below. Failure to do so
will result in harness plug failure and the trip unit
will not provide protection. If the converted breaker
is energized or primary injected with the mounting
plate not installed or installed improperly, damage
will result to the trip unit, wire harness, 36-pin
connector, and current sensors. Failure to adhere to
these instructions will void all warranties.
1. Slide the adapter bracket onto the 36-pin connector, as shown in Figure 35. Be sure that the
beveled corners of the trip unit connector are
facing toward the right side, the adapter bracket
slides are in place behind the notches on either
side of the connector body, and the connector’s
tabs align with the notches on the bottom of the
adapter bracket.
2. Hold the adapter bracket tight to the trip unit
connector and bend the two locking tabs on the
adapter bracket over the connector body, as
shown in Figure 36.
Figure 34. 36-pin trip unit connector.
Figure 35. 36-pin connector adapter bracket.
Figure 36. Adapter bracket locking tabs.
3. Slide the adapter bracket and connector assembly over the guide pins of the trip unit bracket.
Press the two steel push nuts provided onto the
guide pins using a nut driver, as shown in Figure
37, until the assembly is held firmly against the
trip unit mounting plate.
4. While holding the adapter bracket and connector
assembly firmly in place against the mounting
plate, bend the two locking tabs on the mounting
plate into the mating notches on the adapter
bracket using a screwdriver, as shown in Figure
38.
Figure 37. Installing the push nuts onto the guide pins.
Figure 38. Locking tabs on mounting plate.
Installing the Trip Unit Bracket
1. Secure the trip unit bracket assembly and the
auxiliary switch mounting plate to the breaker
with the three 1/4-20 x 3/4" screws, flat washers,
lock washers, and hex nuts provided, as shown
in Figure 39.
2. Attach the remaining mounting screws (removed
earlier) to the auxiliary switch mounting plate.
Installing the Wiring Harness
The wiring harness consists of a section for the trip
unit and another for communication. The communication harness is supplied with all kits, but may not
be required for MicroVersaTrip Plus™ trip units.
Separate and route the wiring harness as follows:
1. The four-pin flux shifter connector and the CT
wire leads should be routed through the wiring
hole in the auxiliary switch mounting plate or
just behind the mounting plate, as shown in Figure 39. The wiring harness should run along the
inside front edge of the breaker right side frame.
Connect the four-pin connector to its mating
connector on the flux shifter assembly. Tie the
harness away from any moving parts or sharp
edges, as shown in Figure 40.
2. Route the CT wires along the inside bottom edge
of the breaker right side frame toward each pole
assembly and connect to the mating lugs on the
phase sensors, as shown in Figure 41. Be sure to
observe proper polarity, with the white lead
connecting to the tap (X2) and the black lead to
common (X1).
Figure 40. Flux shifter wiring harness leads.
Trip Unit
Bracket
Figure 39. Installing the trip unit bracket.
Figure 41. CT wiring harness leads.
3. When the communications and/or the neutral CT
wiring are installed, tie these leads to the front of
the breaker where they will be accessible in the
switchgear cubicle. The actual location is
dependent on the configuration of the switchgear
assembly and the location of the mating
equipment in the switchgear. The installation and
termination points of these components may be
determined by a field engineer. If either the
communications or neutral CT wiring are
installed, a caution label, illustrated in Figure 42,
should be mounted on the breaker and on the
compartment door as a warning to prevent
damage
A mounting plate is supplied with each conversion kit for locating the communication connector of the wiring harness. When the communication and/or neutral CT wiring are not used, they
should be coiled and tied next to the trip unit
bracket, as shown in Figure 43.
Figure 42. Caution label to be applied to the breaker and
compartment door.
Figure 43. Unused communications and neutral CT wiring tied
off.
SECTION 5. INSTALLING THE TRIP
UNIT
The trip unit is attached to the trip unit mounting
bracket. Guide pins in the bracket mate with the
holes on either side of the trip unit box. The guide
pins provide the necessary alignment for the connector engagement. The locking lever engages with
the pin, which is assembled to the trip unit, and
secures the trip unit to the mounting bracket.
Use the following procedure to install the trip unit:
1. Line up the trip unit with the mounting plate.
Insert the guide pins into their holes push on the
trip unit. This will engage the connectors and
release the locking lever, which will move
upward.
2. Verify that the locking lever engaged with the pin
on the rear of the trip unit.
To remove the trip unit, pull the locking lever down
to release the pin on the rear of the unit. Pull the trip
unit straight off the mounting plate.
WARNING: Be sure to perform the continuity test
described in step 1 of Testing in Section 7 before
energizing or performing a primary injection test on
the converted breaker. Failure to do so may result in
damage to the trip unit, wire harness, 36-pin
connector, and CTs.
Figure 44. Installing the trip unit on its mounting plate.
SECTION 6. FOUR-WIRE GROUND
FAULT OPTION
The ground fault option for four-wire installations
requires the installation of an additional current
sensor on the neutral bus in the equipment. The
sensor is connected to the trip unit through the
connector provided in the wiring harness.
1. Mount the neutral sensor on the outgoing neutral
lead, normally in the bus or cable compartment
in the equipment. Figure 45 shows the sensor
outline for K-3000, K-3000S, K-4000, and K-4000S
breakers.
2. Connect the neutral sensor wire harness to the
correct terminals on the sensor. To maintain the
same polarity as the phase sensors, connect the
white wire to the common terminal, black to the
tap.
3. Route the wires through the equipment and connect to the two-pin connector on the trip unit wiring harness. The wires should be tied to the
breaker frame in an easily accessible location.
Figure 45. Neutral sensor outline for I-T-E® K-3000, K-3000S, K-4000, and K-4000S breakers.
SECTION 7. TESTING AND TROUBLESHOOTING
WARNING: Do not change taps on the current sensors or adjust the trip unit settings while the
breaker is carrying current.
Testing
1. Verify that the trip unit is securely installed by
performing a continuity test on the CT wiring and
the trip unit.
a. Disconnect the black CT wires at each phase
sensor.
b. Check for continuity with a continuity tester or
VOM from the white lead of the phase A CT to
the white lead of the phase B CT.
c. Repeat this continuity test for the white leads
of the phase A and phase C CTs.
d. Measure the resistance across each phase
sensor and compare the values measured to
the values listed in Table 1.
e. Reconnect the black CT leads to all of the
phase sensors. Ensure that this is done before
continuing with performance testing of the
breaker.
CAUTION: In addition to the continuity test
described in Step 1 and before performance testing
of the converted breaker, each phase of the breaker
should be primary injected with a current level of
about 10%, but no more than 20%, of the CT rating.
During the application of test current, activate the
trip unit screen by depressing the battery button on
the trip unit face and check that the test current is
displayed on the screen for each phase tested. If the
trip unit fails to display the test current, stop the
test immediately and verify the installation of the
trip unit and wire harness before proceeding with
any additional testing.
WARNING: If the converted breaker is energized or
tested by primary injection with a sufficiently high
test current with a loose or open circuit between the
CTs and the trip unit, damage will occur to the trip
unit, wire harness, 36-pin trip unit connector, and
CTs. Failure to adhere to these instructions will void
all warranties.
2. Check the insulation on the primary circuit with a
1,000-volt Meggar.
3. Measure the resistance across the line and load
terminals for each phase using a micro-ohmmeter or millivolt tester. If the resistance differs
considerably from phase to phase, the electrical
connections may not be properly tightened or it
could also indicate improper contact wipe.
4. To verify that the breaker has been properly
retrofitted, perform a primary injection test on
each phase. This test will check the CTs, bus,
wiring harness, flux shifter, and trip unit as a
complete system.
a. A high-current, low-voltage power supply
should be connected across each line and load
terminal to simulate an overcurrent fault.
b. Set the long-time trip at 0.5 to minimize the
breaker stress.
c. When ground fault is installed, the test can be
performed by wiring two adjacent poles in
series or by using the GE Digital Test Kit, cat.
no. TVRMS2. This will prevent the breaker
from tripping because of an unbalanced current flow.
CAUTION: Do not attempt to use GE Test Kit cat.
no. TVTS1 or TVRMS on this trip unit.
Trouble-Shooting
When malfunctioning is suspected, first examine the
breaker and its power system for abnormal conditions such as the following:
• The breaker is not tripping in response to overcurrent conditions or incipient ground faults.
• The breaker is remaining in a trip-free state
because of mechanical interference along its trip
shaft.
• The shunt trip (if present) is activating improperly.
Nuisance Tripping on Ground Fault-Equipped
Breakers
When nuisance tripping occurs on breakers equipped
with ground fault trip, a probable cause is the
existence of a false ground signal. Each phase sensor
is connected to summing circuitry in the trip unit.
Under no-fault conditions on three-wire load circuits,
the currents add to zero and no ground signal is
developed. This current sum is zero only if all three
sensors have the same electrical characteristics. If
one sensor differs from the others (such as a
different rating or wrong tap setting), the circuitry
can produce an output sufficient to trip the breaker.
Similarly, a discontinuity between any sensor and
the trip unit can cause a false trip signal.
The sensors and their connections should be closely
examined if nuisance tripping is encountered on any
breaker whose MicroVersaTrip Plus or MicroVersaTrip PM trip unit has previously demonstrated satisfactory performance. After disconnecting the breaker
from all power sources, perform the following
procedure:
1. Check that all phase sensors are the same type
(current range).
2. Verify that the tap settings on all three phase sensors are identical.
3. Verify that the wiring harness connections to the
sensors have the proper polarity (white lead to
common, black lead to tap), as shown in the
cabling diagram in Figure 46.
4. On ground fault breakers serving four-wire loads,
check that the neutral sensor is properly connected, as indicated in Figure 46. In particular,
check the following:
a. Verify that the neutral sensor has the same rat-
ing and tap setting as the phase sensors.
b. Verify continuity between the neutral sensor
and its equipment-mounted secondary disconnect block. Also check for continuity from the
breaker-mounted neutral secondary disconnect block through to the trip unit wiring harness connector.
c. If the breaker’s lower studs connect to the
power source, then the neutral sensor must
have its load end connected to the source.
d. Verify that the neutral conductor is carrying
only the neutral current associated with the
breaker’s load current (the neutral is not
shared with other loads).
5. If the preceding steps fail to identify the problem,
then measure the sensor resistances. The appropriate values are listed in Table 1. Since the
phase and neutral sensors are electrically
identical, their resistances should agree closely.
Breaker CT Rating, A Resistance, ohms
K-3000
K-3000S
K-4000
K-4000S
3000 61–67
4000 29–39
Table 1. CT resistance values.
Figure 46. Cabling diagram for MicroVersaTrip Plus™ and MicroVersaTrip PM™ trip units with ground fault on four-wire loads.
NOTES
These instructions do not cover all details or variations in equipment nor do they provide for every possible
contingency that may be met in connection with installation, operation, or maintenance. Should further
information be desired or should particular problems arise that are not covered sufficiently for the purchaser’s
purposes, the matter should be referred to the GE Company.
g
GE Industrial Systems
General Electric Company
41 Woodford Ave., Plainville, CT 06062
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