GE Industrial Solutions EntelliGuard 800–2000 A Frames, 240–600 Vac Maintenance Manual - Manual (Page 55)

EntelliGuard™ 800–2000 A Power Circuit Breakers
Chapter 8. Accessory Maintenance
45
8.5 Open-Fuse Lockout
The Open-Fuse Lockout, illustrated in Figure 56, trips the
breaker to prevent single-phasing when a primary fuse
blows. In 800 A and 1600 A breakers, it is connected
directly to the primary fuse terminals. In 2000 A breakers,
the device is used in combination with a fuse rollout
element and is connected to the secondary disconnect.
This accessory is available only as a factory-installed
option.
The Open-Fuse Lockout contains an individual trip sole-
noid for each pole, connected directly across the fuse in
that phase. When any fuse blows, its solenoid is energized
through connections to the secondary disconnect, illus-
trated in Figure 57, and trips the breaker. An indicator
shows which fuse has blown. The breaker cannot be
reclosed until the blown fuse is replaced and the RESET
button is pressed on the Open-Fuse Lockout.
Figure 56. Open-Fuse Lockout accessory.
Figure 57. Open-Fuse Lockout connections to the secondary disconnect
for EGF-20 breakers
Removing the Open-Fuse Lockout, 800 A
and 1600 A Breakers
Use the following procedure, illustrated in Figure 58, to
remove the Open-Fuse Lockout for replacement.
1. Follow the six wires from the Open-Fuse Lockout to
their connection points on either side of each
primary fuse. Disconnect the wires from the primary
conductors. Cut the wire ties as necessary to release
the wires back to the Open-Fuse Lockout.
2. Remove the three mounting bolts and lock washers
securing the Open-Fuse Lockout to the bottom plate
of the breaker.
3. Remove the Open-Fuse Lockout straight out from
the front of the breaker.
Installing the Open-Fuse Lockout, 800 A and
1600 A Breakers
Use the following procedure, illustrated in Figure 58, to
install a replacement Open-Fuse Lockout.
4. Place the replacement Open-Fuse Lockout in
position, carefully guiding the trip rod through the
hole in the trip rod guide.
5. Insert the three bolts and lock washers from the top
of the breaker bottom plate into the tapped holes in
the Open-Fuse Lockout mounting bracket. Tighten
to 96 in-lb.
6. Connect wires from each Open-Fuse Lockout coil
across the coil’s respective primary fuse. For
example, wires from the Phase A coil, marked “L”
on the Open-Fuse Lockout label, should be
connected on opposite sides of the Phase A
(leftmost from the front) primary fuse.
7. Adjust the Open-Fuse Lockout as follows:
a. Charge the closing springs with the manual
charging handle and close the breaker.
b. The dimension between the end of the trip rod
and the trip paddle should be 0.10–0.14 inch. If
necessary, loosen the trip rod lock nut and run
the rod in or out to attain the proper clearance.
c. With the Open-Fuse Lockout energized, the
breaker must TRIP and the RESET button must
move forward to the front plate. In this condition,
the breaker must be held trip free.
Removing the Open-Fuse Lockout, 2000 A
Breakers
Use the following procedure, illustrated in Figure 58, to
remove the Open-Fuse Lockout for replacement.
1. Disconnect the wires from the Open-Fuse Lockout at
terminals 22, 23, 24, 25, 26, and 27 of the secondary
disconnect block. Cut any wire ties, as necessary to
release the wires back to the Open-Fuse Lockout.
22
2
1
OFLO
Phase A
23
24
4
3
OFLO
Phase B
25
26
6
5
OFLO
Phase C
27