DEH–40032A Installation Instructions
g
INTRODUCTION
GE Conversion Kits are designed for upgrading
®
existing Westinghouse
circuit breakers, rather than replacing the entire
breaker. The Conversion Kits include ProTrip™
Trip Units, the latest 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 Westinghouse Type DB-75,
DBL-75, DB-100, and DBL-100
power circuit breakers. Each Conversion Kit
contains all the components needed to convert
from an existing Westinghouse
electromechanical trip system.
low-voltage power
low-voltage
ProTrip™ Conversion Kits
For Westinghouse
®
Type DB-75, DBL75, DB-100,
DBL-100 Low-Voltage Power Circuit
Breakers
TABLE OF CONTENTS
INTRODUCTION.........................................................................................................................................................1
SECTION 1. GENERAL INFORMATION............................................................................................................4
SECTION 2. BEFORE INSTALLATION
..............................................................................................................4
SECTION 3. BACK FRAME BREAKER CONVERSION
Removing the Electromechanical Trip Devices......................................................................................5
Installing the Phase Sensors (CTs) ........................................................................................................6
SECTION 4. FRONT FRAME BREAKER CONVERSION
Installing the Trip Paddle ........................................................................................................................7
Installing the Trip Unit Mounting Bracket................................................................................................7
Adjusting the Flux Shifter........................................................................................................................8
Connecting the Trip Unit Wiring Harness ...............................................................................................9
Installing the Trip Unit ...........................................................................................................................10
Configuring the Trip Unit.......................................................................................................................10
SECTION 5. FOUR-WIRE GROUND FAULT OPTION................................................................................11
SECTION 6. TESTING AND TROUBLE-SHOOTING
Testing ..................................................................................................................................................12
Trouble-Shooting...................................................................................................................................12
Nuisance Tripping on Ground Fault-Equipped Breakers.........................................................12
2
LIST OF FIGURES
1. Removing a trip device.....................................................................................................................................5
2. Electromechanical trip devices removed from the breaker..............................................................................5
3. Preparing the load terminals............................................................................................................................6
4. CTs installed on the breaker............................................................................................................................6
5. Trip paddle installed on the trip bar..................................................................................................................7
6. Trip unit mounting bracket................................................................................................................................ 7
7. Installing the support bracket...........................................................................................................................7
8. Trip unit mounting bracket installed on the breaker frame. ............................................................................. 8
9. Adjusting the flux shifter...................................................................................................................................8
10. Wiring harness installation on the CTs. ...........................................................................................................9
11. Trip unit attached to its mounting plate..........................................................................................................10
12. Harness connector attached to the trip unit...................................................................................................10
13. Mounting the trip unit on the breaker. ............................................................................................................ 10
14. Neutral sensor outline for a DB-75 or DB-100 breaker..................................................................................11
15. Cabling diagram for ProTrip™ trip units with ground fault on four-wire loads...............................................14
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. Then 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 installations
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. BACK FRAME BREAKER
CONVERSION
The back frame conversion of a Westinghouse DB-75 or
DB-100 breaker consists of the following steps:
1. Remove the breaker to a clean, well-lighted work
bench and place it on its left side, so that both the
bottom and back are easily accessible.
2. Remove the existing electromechanical trip devices.
3. Install the new phase sensors (CTs).
Removing the Electromechanical Trip
Devices
1. Remove and discard the four bolts holding each trip
device to a pole of the breaker, as shown in Figure 1.
2. Remove and discard the three electromechanical trip
devices, shown in Figure 2.
CAUTION: Do not remove the trip paddles from the
common trip bar. They are used to balance the trip
action and could cause nuisance tripping if removed.
Figure 1. Removing a trip device.
Figure 2. Electromechanical trip devices removed from
the breaker.
5
Installing the Phase Sensors (CTs)
1. On draw-out type breakers, remove and save the
load-side draw-out finger assemblies, as shown in
Figure 3.
2. Remove and discard the two bolts above and the two
bolts below each load terminal, as shown in Figure 3.
3. Place each of the CTs provided over a load terminal
with the wire terminal at the top, as shown in Figure
4.
1
4. Secure the CTs with the four
head bolts and lock washers provided, as shown in
Figure 4.
NOTE: In some stationary breaker applications it may
be necessary to install the breaker before bolting the
CTs into place. In such cases, slide a CT over each bus
before bolting the breaker into the equipment.
/2-13 x 23/4" Allen-
Figure 4. CTs installed on the breaker.
Figure 3. Preparing the load terminals.
6
SECTION 4. FRONT FRAME
BREAKER CONVERSION
Installing the Trip Paddle
1. Remove the 1/4-20 bolt that fastens the draw-out
interlock lever to the common trip bar, as shown in
Figure 5.
2. Install the new trip paddle provided over the existing
interlock lever and secure it with the existing
hardware, as shown in Figure 5.
Installing the Trip Unit Mounting Bracket
The trip unit mounting bracket, shown in Figure 6,
mounts the flux shifter and trip unit to the breaker frame.
1. Mount the trip unit mounting bracket to the right side
of the breaker frame, as shown in Figure 8. Insert the
5
/16-18 x 11/4" bolt with two flat washers up through
the frame and the hole in the bottom of the bracket.
Secure with a lock washer and nut.
2. Install the support bracket provided to strengthen the
top of the trip unit bracket, as shown in Figure 7.
Attach the support bracket to the trip unit mounting
bracket with the
bracket as a template to locate the position in the
breaker frame to drill a hole to accommodate a
bolt.
3. Slide the support bracket to the inside of the right
breaker frame member, as shown in Figure 8, and
secure it with the
nut provided.
1
/4-20 x 3/4" bolt provided. Use the
1
1
/4-20 x 3/4" bolt, lock washer, and
/4"
Figure 6. Trip unit mounting bracket.
Figure 5. Trip paddle installed on the trip bar.
Figure 7. Installing the support bracket..
7
Adjusting the Flux Shifter
With the breaker in the CLOSED position, the gap
between the adjustment screw and the trip paddle should
1
/32 inch, as shown in Figure 9. For safety, OPEN the
be
1
breaker before adjusting the screw with a
wrench. CLOSE the breaker to check the adjustment.
WARNING: Be extremely careful when working on a
CLOSED breaker. Do not reach into the mechanism
while adjusting the flux shifter.
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.
/4-inch
Figure 8. Trip unit mounting bracket installed on the
breaker frame.
Figure 9. Adjusting the flux shifter.
8
Connecting the Trip Unit Wiring Harness
1. Join the four-pin connector on the trip unit harness to
the four-pin connector on the flux shifter.
2. Bring the CT leads of the wiring harness around to
the back and bottom of the breaker, as shown in
Figure 10. Connect the harness leads to the screw
terminals on each CT. The black wire (tap) connects
to the “B” terminal and the white wire (common) to
the “W” terminal.
NOTE: Some stationary breaker applications may
require mounting the CTs over the line terminals. If this
is the case, the polarity of the wiring harness leads to
the CTs must be reversed.
3. Use the wire ties provided to secure the harness
back against the frame. Ensure that the wiring will
not interfere with any moving parts.
Figure 10. Wiring harness installation on the CTs.
9
Installing the Trip Unit
1. Place a lock washer and flat washer over each of the
three
through the mounting holes on the trip unit mounting
plate. From the rear of the plate, place a flat washer,
spacer, and O-ring over the screws, as shown in
Figure 11.
2. 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 11.
3. 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 12.
4. Place the trip unit and mounting plate in position on
the support bracket mounted to the breaker. Secure
with the screws in the mounting plate into the tapped
holes in the bracket, as shown in Figure 13.
1
/4-20 x 13/8" screws provided and insert
Configuring the Trip Unit
See DEH-40034 for detailed instructions for setting up
ProTrip trip units.
Figure 12. Harness connector attached to the trip unit.
Figure 11. Trip unit attached to its mounting plate.
Figure 13. Mounting the trip unit on the breaker.
10
SECTION 5. 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 14 shows the outline of the neutral
sensor for a DB-75 or DB-100 breaker.
2. Connect the neutral sensor wire harness to the
correct taps 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 14. Neutral sensor outline for a DB-75 or DB-100 breaker.
11
SECTION 6. 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 Megger.
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 15.
4. On ground fault breakers serving four-wire loads,
check that the neutral sensor is properly connected,
12
as indicated in Figure 15. 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 1. Since the phase
and neutral sensors are electrically identical, their
resistances should agree closely.
Breaker CT Rating, A Resistance,
ohms
DB-75
DBL-75
DB-100
DBL-100
3000 56–68
4000 72–88
Table 1. CT resistance values.
13
Figure 15. Cabling diagram for ProTrip™ trip units with ground fault on four-wire loads.
14
NOTES
15
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.
General Electric Company
41 Woodford Ave., Plainville, CT 06062
DEH40032 R02 0899 © 1999 General Electric Company
g GE Industrial Systems
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