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DEH–40028 Installation Instructions
ProTrip™ Conversion Kits
For GE Types AK-50, AKU-50, AKS-50,
AKT-50, AK-75, and AK-100 LowVoltage Power Circuit Breakers
INTRODUCTION
GE Conversion Kits are designed for upgrading existing
GE low-voltage power circuit breakers, rather than
replacing the entire breaker. The Conversion Kits include
ProTrip™ Trip Units, the latest technological advance in
GE trip systems.
ProTrip 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 ProTrip Conversion
Kits on GE types AK-50, AKU-50, AKS-50, AKT-50, AK75, and AK-100 low-voltage power circuit breakers. Each
Conversion Kit contains all the components needed to
convert from an existing GE type EC trip system.
TABLE OF CONTENTS
SECTION 1. GENERAL INFORMATION............................................................................................................4
SECTION 2. BEFORE INSTALLATION..............................................................................................................4
SECTION 3. FRONT FRAME BREAKER CONVERSION
Relocating and Remounting the W and X Relays ..................................................................................5
Installing the Flux Shifter Assembly........................................................................................................6
Breakers with EC or Power Sensor Trip Systems.....................................................................6
Breakers with a Side Bracket.....................................................................................................7
AKU-50 Breakers Only...............................................................................................................7
Breakers with ECS or SST Trip Systems ..................................................................................8
Installing the Trip Paddle ........................................................................................................................8
Adjusting the Flux Shifter........................................................................................................................8
Installing the Trip Unit Mounting Bracket................................................................................................9
EC or Power Sensor Trip System..............................................................................................9
ECS or SST Trip System ...........................................................................................................9
SECTION 4. BACK FRAME CONVERSION
Crossbar Modification ...........................................................................................................................10
Removing the Existing Trip Devices.....................................................................................................11
AK-50 & AKS-50 Breakers with EC or Power Sensor Trip Systems.......................................11
AK-50 & AKS-50 Breakers with SST Trip Systems.................................................................11
AK-75 & AK-100 Breakers with EC or Power Sensor Trip Systems .......................................11
AK-75 & AK-100 Breakers with SST Trip Systems .................................................................11
Installing the Phase Sensors ................................................................................................................12
AK-50 & AKS-50 Breakers.......................................................................................................12
AK-75 & AK-100 Breakers.......................................................................................................13
SECTION 5. INSTALLING THE TRIP UNIT
Configuring the Trip Unit.......................................................................................................................14
SECTION 6 FOUR-WIRE GROUND FAULT OPTION
Installing the Fourth-Wire Disconnect...................................................................................................15
AK-50 & AKS-50 Stationary Breakers .....................................................................................15
AK-50 & AKS-50 Draw-Out Breakers......................................................................................16
AK-75 & AK-100 Draw-Out Breakers.......................................................................................16
Installing the Neutral Sensor.................................................................................................................18
SECTION 7. EQUIPMENT CONVERSION
Installing Mounting Brackets.................................................................................................................20
SECTION 8. TESTING AND TROUBLE-SHOOTING
Testing ..................................................................................................................................................22
Trouble-Shooting...................................................................................................................................22
Nuisance Tripping on Ground Fault-Equipped Breakers.........................................................22
APPENDIX – DRILL TEMPLATES
Appendix 1. Drill Template for Flux Shifter Mounting ...........................................................................25
Appendix 2. Drill Template for Trip Unit Mounting................................................................................27
Appendix 3. Drill Template for Flux Shifter Mounting ...........................................................................27
2
LIST OF FIGURES
1. Relocation and remounting of the W and X relays...........................................................................................5
2. New X and W relay mounting brackets............................................................................................................ 5
3. Flux shifter assembly........................................................................................................................................6
4. Pattern for flux shifter mounting holes in the side frame..................................................................................6
5. Flux shifter assembly mounted to the side frame. ...........................................................................................6
6. Location of new hole in the flux shifter base....................................................................................................7
7. Locations of new holes for mounting the OFLO terminal block.......................................................................7
8. Existing trip paddles to be removed.................................................................................................................8
9. Installing the new trip paddle............................................................................................................................8
10. Adjusting the flux shifter................................................................................................................................... 8
11. Mounting hole drill pattern for the trip unit mounting plate............................................................................... 9
12. Trip unit mounting plate attached to the breaker front channel.......................................................................9
13. Trip unit mounting bracket attached to the mounting plate..............................................................................9
14. Actuator bracket attached to the left pole link................................................................................................10
15. Drill pattern for actuator bracket mounting holes. .......................................................................................... 10
16. Existing EC trip devices before removal........................................................................................................ 11
17. Removal of EC trip devices............................................................................................................................ 11
18. Parts provided for CT installation per pole.....................................................................................................12
19. CT post mounted in the breaker back frame..................................................................................................12
20. CT installation completed...............................................................................................................................12
21. Phase sensor installation on AK-75 & AK-100 breakers...............................................................................13
22. Attaching the trip unit to the mounting plate...................................................................................................14
23. Trip unit mounted on the breaker...................................................................................................................14
24. Fourth-wire terminal board installation on AK-50 & AKS-50 stationary breakers.......................................... 15
25. Fourth-wire disconnect installed on AK-50 & AKS-50 draw-out breakers.....................................................16
26. Fourth-wire disconnect assembly for AKD-5 or AKD-6 equipment................................................................16
27. Fourth-wire disconnect assembly for AKD equipment...................................................................................16
28. K-75 & AK-100 back frame conversion..........................................................................................................17
29. Outline of the neutral sensor for AK-50 breakers........................................................................................... 18
30. Outline of the neutral sensor for AK-75 and AK-100 breakers ......................................................................19
31. AK-50 & AKS-50 fourth-wire disconnect for AKD. .........................................................................................20
32. AK-75 & AK-100 fourth-wire disconnect for AKD-5 & AKD-6. .......................................................................20
33. AK-100 fourth-wire disconnect for AKD. ........................................................................................................20
34. AK-50 & AKS-50 fourth-wire disconnect for AKD. .........................................................................................21
35. Fourth-wire disconnect for AKD-5 & AKD-6...................................................................................................21
36. Cabling diagram for ProTrip™ trip units with ground fault on four-wire loads...............................................24
3
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
ProTrip 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 ProTrip kit 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.
Note that all ProTrip trip units supplied with conversion
kits are equipped with long-time, short-time,
instantaneous, and defeatable ground fault (LSIGX) trip
functions. The installer should be aware of how these
functions will affect his application before installing the
conversion kit.
As a service-related consideration, the installation of a
ProTrip kit provides an excellent opportunity to perform
normal maintenance on the breaker, particularly when
the front and back frames are separated. 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, well-lighted
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 lock-out
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 an OPEN breaker
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.
4
SECTION 3. FRONT FRAME
BREAKER CONVERSION
Front frame conversion consists of the following steps:
1. Separation of the front and back breaker frames for
AK-50, AKU-50, AKS-50, and AKT-50 breakers.
(Frame separation is not necessary for AK-75 and
AK-100 breakers.) Refer to the appropriate
installation and maintenance manuals supplied with
the breakers and equipment for instructions on frame
separation. Copies of these publications may be
obtained from your local GE sales office.
2. Relocation and remounting the W and X relays on
AK-50, AK-75, and AK-100 electrically operated
breakers with EC trip devices.
3. Installation of the flux shifter assembly and trip
paddle.
4. Installation of the trip unit mounting bracket.
5. Installation of the trip unit wiring harness.
Relocating and Remounting the W and X
Relays
This step is necessary on electrically operated breakers
with EC trip devices. Figure 1 illustrates this process.
Figure 2 shows the new mounting brackets supplied with
the kit.
1. Remove the W relay and install the mounting bracket
supplied with the conversion kit to the upper left side
of the frame
2. Remove the X relay and its mounting bracket. Use
the new bracket supplied with the conversion kit to
remount the X relay in its existing position.
Figure 1. Relocation and remounting of the W and X
relays.
W Relay
X Relay
Figure 2. New X and W relay mounting brackets.
5
Installing the Flux Shifter Assembly
The installation procedure for the flux shifter assembly,
illustrated in Figure 3, varies depending on the type of
breaker and existing trip device. In some cases,
mounting holes must be added, terminal blocks
relocated, or breaker side rails removed.
Breakers with EC or Power Sensor Trip Systems
1. Drill the flux shifter mounting holes in the left side of
the breaker frame. The mounting hole pattern is
illustrated in Figure 4. A full-size template is provided
in the Appendix.
2. Mount the new flux shifter to the inside of the side
frame with the three screws, lock washers, flat
washers, and nuts supplied, as shown in Figure 5.
Insert the screws from the outside of the side frame.
Figure 4. Pattern for flux shifter mounting holes in the
side frame.
Figure 3. Flux shifter assembly.
Mounting
Screws
Flux Shifter
Assembly
Figure 5. Flux shifter assembly mounted to the side
frame.
6
Breakers with a Side Bracket
1. Drill a 3/4” diameter hole into the flux shifter
assembly mounting base to provide the necessary
clearance for the bracket. The location of the new
hole is shown in Figure 6.
2. Remove the side bracket from the frame and drill the
holes according to the pattern in Figure 4. A full-size
template is provided in the Appendix. After the holes
are drilled, return the side bracket to its original
location.
3. Mount the new flux shifter to the inside of the side
frame with the three screws, lock washers, flat
washers, and nuts supplied, as shown in Figure 5.
The upper two screws are inserted from the outside
of the frame, while the lower screw must be inserted
from the inside.
AKU-50 Breakers Only
For easier installation of the new flux shifter assembly on
AKU-50 breakers, the open-fuse lockout (OFLO) may be
removed from the breaker.
1. Remove the three bolts attaching the OFLO to the
base of the breaker.
2. The OFLO terminal block must be relocated on the
upper left side of the breaker. Some parts and tool,
not provided with the kit, are necessary for this task:
• Six strips of 14 AWG wire
• Wire splice
• 12 butt splices
• Wire labels
• Drill and size F bit
5
/16-18 tap
•
• Flathead screw driver
• Two
3. Drill and tap two holes for the
5
/16-18 bolts and lock washers
5
/16-18 bolts. Figure 7
shows the hole locations.
4. Remove the three bolts securing the OFLO to the
breaker and lift off the OFLO device.
5. Remove the wires that connect the OFLO device to
the terminal block.
6. Cut the wires that connect to the coils where they join
and label the wires. Attach butt splices to all twelve
open ends.
7. Connect the strands of wire to the OFLO. Mount the
terminal block in its new location. DO NOT complete
the wire connections until the flux shifter is installed.
8. Install the new flux shifter assembly as described
above and shown in Figure 5.
9. Connect the cables attached to the terminal block
and tie them together.
Figure 6. Location of new hole in the flux shifter base.
Figure 7. Locations of new holes for mounting the OFLO
terminal block.
7
Breakers with ECS or SST Trip Systems
1. Remove the ECS or SST trip unit.
2. Remove the existing flux shifter device and the trip
unit control harness.
3. Install the new flux shifter assembly as described
above and shown in Figure 5.
Installing the Trip Paddle
For breakers equipped with an ECS or SST trip system,
the existing trip paddle is used with the new flux shifter.
For all other breakers, the existing trip paddles must be
removed and the new trip paddle installed as follows:
1. Remove and discard the three trip paddles on the trip
actuator bar, as shown in Figure 8.
2. Assemble the trip paddle and the threaded back
plate by inserting two of the 10-32 x
lock washers provided along the top edge.
3. Slip the trip paddle over the trip actuator bar
approximately one inch from the side frame, as
shown in Figure 9. Insert the remaining 10-32 x
screw and tighten the other screws to secure the trip
paddle in place.
3
/4" screws and
3
/4"
Figure 8. Existing trip paddles to be removed.
Adjusting the Flux Shifter
After the flux shifter and trip paddle are installed and the
breaker frames are reassembled, the following
adjustments must be made.
1. With the breaker OPEN and the mechanism charged,
set the gap between the trip paddle and the end of
the flux shifter rod at 0.10 inch, as shown in Figure
10. Use a 0.10-inch diameter rod. Set the adjuster
end of the trip rod and lock it in place with the jam
nut. Note that removal of the buffer stud will make
the trip paddle easier to install and adjust.
2. As the crossbar travels between the breaker
CLOSED and OPEN positions, the tang of the
actuator bracket must clear the buffer stud. If there is
insufficient clearance, loosen the two mounting
screws and rotate the bracket clockwise to take up
mounting hole slack. Retighten the screws.
3. Optional Test – The flux shifter may be tested by
closing the breaker and applying a 9 Vdc power
source to the flux shifter leads (the red wire is positive). The breaker should trip.
Figure 9. Installing the new trip paddle.
Figure 10. Adjusting the flux shifter.
8
Installing the Trip Unit Mounting Bracket
The new ProTrip trip unit mounts to the left side of the
front channel. A mounting bracket is shock--mounted to a
plate that is assembled to the front channel.
EC or Power Sensor Trip System
1. The holes for the new mounting plate may have to be
added to the front channel. The drill pattern is shown
in Figure 11, with a full-size template in the
Appendix. Tap the holes for
2. Attach the new mounting plate, as shown in Figure
12, with two short
1
/4-20 screws and lock washers on
the top and the single long
washer on the bottom. Be sure to insert the spacer
between the mounting plate and the breaker channel,
as shown.
3. Attach the trip unit mounting bracket to the plate with
two screws, lock washers, and flat washers, as
shown in Figure 13.
1
/4-20 screws.
1
/4-20 screw and lock
ECS or SST Trip System
Remove the existing mounting plate and bracket. Install
the new mounting plate and bracket, using the holes
closest to the front of the breaker, as described in steps 2
and 3 above.
If the manual indicator assembly busing on AK-50
manual breakers interferes with the mounting bracket
installation, then the bracket must be modified. Cut off a
3/4 x 11/2 inch section from the right front of the plate to
provide clearance.
Figure 12. Trip unit mounting plate attached to the
breaker front channel.
Figure 13. Trip unit mounting bracket attached to the
mounting plate.
Figure 11. Mounting hole drill pattern for the trip unit
mounting plate.
9
SECTION 4. BACK FRAME
CONVERSION
The back frame conversion consists of the following
operations:
1. Modification of the crossbar assembly for the flux
shifter installation.
2. Removal of the existing trip devices.
3. Installation of the phase sensors.
4. Installation of the back frame harness.
Crossbar Modification
The flux shifter reset linkage is driven by the actuator
bracket, as shown in Figure 3. The actuator bracket must
be assembled to the left side link of the left pole, as
shown in Figure 14.
If the actuator bracket mounting holes are not in the left
side link, the holes must be added. Drill and tap two
18 holes using the pattern in Figure 15. A full-size
template is provided in the Appendix.
5
/16-
Figure 14. Actuator bracket attached to the left pole link.
Figure 15. Drill pattern for actuator bracket mounting
holes.
10
Removing the Existing Trip Devices
AK-50 & AKS-50 Breakers with EC or Power Sensor
Trip Systems
1. Remove and discard the two screws at the base of
each trip device, as shown in Figure 16. Discard the
metal mounting brackets.
2. Remove and discard the small Philips-head screw at
the top of each trip device.
5
3. Remove and discard the four
securing each trip coil. The coil can then be lifted off
and removed. Figure 17 shows one trip completely
removed, one with the cover removed, and one still
in place.
AK-50 & AKS-50 Breakers with SST Trip Systems
Remove the existing SST phase sensors in preparation
for installing the new sensors.
AK-75 & AK-100 Breakers with EC or Power Sensor
Trip Systems
Remove the existing trip devices and harnesses and
discard.
/16" Allen-head bolts
Figure 16. Existing EC trip devices before removal.
AK-75 & AK-100 Breakers with SST Trip Systems
The new ProTrip phase sensors are visually identical to
the SST sensors. Remove the existing sensors and
discard.
Figure 17. Removal of EC trip devices.
11
Installing the Phase Sensors
AK-50 & AKS-50 Breakers
Figure 18 shows the parts provided for assembly of the
CT on each pole.
1. Mount the new copper CT post to the back frame
with the two
lock washers provided, as shown in Figure 19.
2. Fasten the three small insulated wire fasteners to the
back frame with the
as shown in Figure 20. One fastener is mounted
under each CT.
3. Place a CT over each copper post, first applying a
small amount of RTV or similar adhesive to prevent
the CTs from rotating.
4. Mount the top copper bus over each CT and secure
with the
and flat washers provided.
5. Insert two
washers through each top copper bus into the
contact arm assembly.
6. Tighten the
bolts to 300 in-lb.
3
/8-16 x 11/2" bolts, flat washers, and
1
/4-20 x 13/4" screws provided,
1
/2-13 x 11/2" Allen-head bolts, lock washers,
3
/8-16 x 11/2" bolts, lock washers, and flat
3
/8-16 bolts to 200 in-lb and the 1/2-13
Figure 18. Parts provided for CT installation for one pole.
WARNING: Step 6 ensures critical electrical integrity
connections. The designated bolts must be correctly
tightened for proper operation. Failure to tighten these
bolts properly will cause a breaker failure, resulting in
property damage and/or personal injury.
Figure 19. CT post mounted in the breaker back frame.
12
Figure 20. CT installation completed..
AK-75 & AK-100 Breakers
1. The ProTrip phase sensors mount on the upper
breaker studs, as shown in Figure 21. The sensors
held on the stud with locking rings. Leave enough of
the stud exposed for the primary fingers to engage.
Engage the sensor’s antiturn lugs with the notch in
the locking ring. Before tightening the locking rings,
position each sensor so that its leads exit between
the pole bases, as shown.
2. Mount the three sensor terminal boards to the rear of
the back frame using the hardware provided.
3. Form each sensor’s leads downward between the
pole bases. (See also Figure 28.)
Figure 21. Phase sensor installation on AK-75 & AK-100 breakers.
13
SECTION 5. INSTALLING THE TRIP
UNIT
1. Remove the large screw from the rear of the trip unit.
Place the trip unit in position on the mounting plate,
with the 50-pin connector aligned with the opening in
the plate. Secure with the large screw, as shown in
Figure 22.
2. Insert the 50-pin female connector on the wiring
harness into the trip unit connector through the rear
of the mounting plate. Secure to the mounting plate
with the two small screws provided, as shown in
Figure 22.
3. Place the trip unit and mounting plate in position on
the support bracket mounted on the breaker. Secure
with the three screws, lock washers, and flat washers
through the holes in the mounting plate into the
tapped holes in the bracket, as shown in Figure 23.
Configuring the Trip Unit
See DEH-40034 for detailed instructions for setting up
ProTrip trip units.
Figure 22. Attaching the trip unit to the mounting plate.
14
Figure 23. Trip unit mounted on the breaker.
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.
Installing the Fourth-Wire Disconnect
AK-50 & AKS-50 Stationary Breakers
The fourth-wire disconnect for stationary breakers
consists of a terminal board mounted to the lower front
channel, as shown in Figure 24.
• If the terminal board is already present on the
breaker, just replace the control harness. Maintain
the following color code: white wire to common,
black wire to the tap.
• If the terminal board must be added, mount it as
shown in Figure 24. The mounting holes may have
to be added to the front channel.
Figure 24. Fourth-wire terminal board installation on AK-
50 & AKS-50 stationary breakers.
15
AK-50 & AKS-50 Draw-Out Breakers
The fourth-wire disconnect for AK-50 and AKS-50 drawout breakers mounts to the lower back frame, as shown
in Figure 25.
• If the terminal board is already present on the
breaker, just replace the control harness. Maintain
the following color code: white wire to common,
black wire to the tap.
• If the disconnect must be added, mount it as shown
in Figure 25.
AK-75 & AK-100 Draw-Out Breakers
There are two fourth-wire disconnect designs used with
these breakers. One design is used on breakers for GE
type AKD switchgear, while the other applies to breakers
for GE types AKD-5 and AKD-6 equipment. The only
difference is the bracket used for mounting the
disconnect to the breaker. Figures 26 and 27 show these
two designs.
The conversion kit contains an assembled, ready-toinstall mounting block and bracket for AKD-5 and AKD-6
installation, plus an addition bracket only for type AKD
equipment installations. For AKD equipment, remove the
bracket from the assembled disconnect and replace it
with the AKD bracket.
The fourth-wire disconnect for AK-75 and AK-100 drawout breakers mounts to the lower back frame as shown in
Figure 28.
• If the terminal board is already present on the
breaker, just replace the control harness. Maintain
the following color code: white wire to common,
black wire to the tap.
• If the disconnect must be added, mount it as shown
in Figure 28.
Figure 25. Fourth-wire disconnect installed on AK-50 &
AKS-50 draw-out breakers.
Figure 26. Fourth-wire disconnect assembly for AKD-5 or
AKD-6 equipment.
Figure 27. Fourth-wire disconnect assembly for AKD
equipment.
16
Figure 28. AK-75 & AK-100 back frame conversion.
17
Installing the Neutral Sensor
The neutral sensor is an electrical duplicate of the phase
sensor, including the taps. Therefore, when taps (if
provided) are changed on the phase sensors, the taps on
the neutral sensor must be similarly changed. For kits
with fixed phase sensors, be sure to use the
corresponding tap on the neutral sensor.
Mount the neutral sensor on the outgoing neutral lead,
normally in the equipment bus or cable compartment.
Figure 29 shows mounting details for the neutral sensor
for AK-50 breakers, while Figure 30 covers AK-75 and
AK-100 breakers.
Figure 29. Outline of the neutral sensor for AK-50 breakers.
18
Figure 30. Outline of the neutral sensor for AK-75 and AK-100 breakers
19
SECTION 7. EQUIPMENT
CONVERSION
Installing Mounting Brackets
The equipment compartment contains the mating
portions of the fourth-wire disconnect and the neutral
sensor. The same disconnect assembly is used for types
AKD, AKD-5, and AKD-6 switchgear. Mounting brackets
for AKD, AKD-5, AKD-6, and AKD-8 switchgear
applications are included in the conversion kit. Figures
31, 32, 33, 34, and 35 are mounting diagrams for the
various applications. Table 1 is a key to the numbers
used in these figures to indicate various hardware items.
Legend Description
225 Breaker portion of fourth-wire disconnect
226 Equipment portion of fourth-wire disconnect
Mounting bracket for AK-100 for AKD
229
230 10-32 x 1.375 inch mounting screw
231 Insulation
232 #10 lock washer
233 #10 flat washer
235 1/8-20 flat washer
236 1/8-20 lock washer
237 1/4-20 nut
238 1/4-20 x 1.25 inch mounting screw
239 Bracket
compartments
Figure 31. AK-50 & AKS-50 fourth-wire disconnect for
AKD.
Figure 32. AK-75 & AK-100 fourth-wire disconnect for
AKD-5 & AKD-6.
Table 1. Legend for number symbols appearing in
Figures 31–35.
Figure 33. AK-100 fourth-wire disconnect for AKD.
20
Figure 34. AK-50 & AKS-50 fourth-wire disconnect for AKD.
Figure 35. Fourth-wire disconnect for AKD-5 & AKD-6.
21
SECTION 8. TESTING AND TROUBLESHOOTING
WARNING: Do not change taps on the current sensors
or adjust the trip unit settings while the breaker is
carrying current. Failure to adhere to these instructions
will void all warranties.
Testing
Before installing a converted breaker back into service,
perform the following steps:
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.
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, 50-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 by 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 ProTrip 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 36.
4. On ground fault breakers serving four-wire loads,
check that the neutral sensor is properly connected,
22
as indicated in Figure 36. In particular, check the
following:
a. Verify that the neutral sensor has the same rating
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 breakermounted 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 2. Since the phase
and neutral sensors are electrically identical, their
resistances should agree closely.
Breaker CT Rating, A Resistance, ohms
AK-50
AKS-50
AK-75
AK-100
300
400
600
800
1200
1600
1200
1600
2000
3000
1600
2000
3000
4000
20–24
27–32
42–50
58–68
93–109
130–154
20–24
28–34
37–44
61–72
36–43
47–55
75–88
108–127
Table 2. CT resistance values.
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Figure 36. Cabling diagram for ProTrip™ trip units with ground fault on four-wire loads.
24
APPENDIX – DRILL TEMPLATES
Appendix 1. Drill Template for Flux Shifter Mounting
25
Appendix 2. Drill Template for Trip Unit Mounting
Appendix 3. Drill Template for Flux Shifter Mounting
27
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
DEH40028 R03 0899 © 1999 General Electric Company
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