GE Industrial Solutions EntelliGuard 800–2000 A Frames, 240–600 Vac Maintenance Manual - Manual (Page 26)

EntelliGuard™ 800–2000 A Power Circuit Breakers
Chapter 5. Breaker Maintenance
16
Separation of Front and Back Frames for
EGX08, EGS16, EGF16, EGH16, EGS20, and
EGF20
The following procedure is illustrated in Figure 10.
1. Verify that the breaker contacts are open and that
the closing springs are discharged.
2. Remove the two bolts and lock washers that attach
the arc chute retainer to the front frame and
remove the retainer. Slide out the arc chutes and
interphase barriers. Note that there are three dis-
tinct types of phase barriers: right, inner (2), and
left.
3. Remove the two screws and standoffs securing each
secondary disconnect to the mounting plate, taking
care to retain the spring washer from the pin on the
underside of the disconnect, as illustrated in Figure
6. Cut the wire ties securing the secondary discon-
nect leads to the mounting plate and to the breaker
back frame. Slide the secondary disconnect off the
support bracket. Secure the secondary disconnect to
the front frame assembly.
4. Remove the three screws and washers that attach
the secondary disconnect mounting plate to the
back frame. Remove the mounting plate.
5. Remove one of the snap rings and slide out the pin
connecting each of the movable contact assemblies
to the breaker main shaft, as illustrated in Figure 9.
On the two outer poles, first remove the bolt and
cover over the outer end of the pin.
6. Carefully place the breaker on its back, resting on
the primary disconnects.
7. Remove the two nuts and lock washers attaching the
tie bars to the front frame.
8. Remove the six nuts and lock washers (the top con-
nections also have spacers) connecting the front
and back frames.
9. Lift the front frame straight off the back frame.
Reconnection of Front and Back Frames for
EGX08, EGS16, EGF16, EGH16, EGS20, and
EGF20
The following procedure is illustrated in Figure 10.
1. Carefully place the back frame on a suitable work
surface, resting on the primary disconnects.
2. Carefully lower the front frame onto the back frame,
lining up the six studs in the sides of the back frame
with the corresponding holes in the front frame.
Attach the six nuts and lock washers, with the two
spacers on the top studs, and tighten to 250 in-lb.
Figure 9. Movable contact connection to the breaker main shaft on
EGX08, EGS16, EGF16, EGH16, EGS20, and EGF20 breakers.
3. Attach the two nuts and lock washers to secure the
tie bars to the front frame. Tighten to 250 in-lb.
4. Carefully place the breaker upright, resting on its
bottom surface.
5. Reconnect the movable contact assemblies to the
breaker main shaft by inserting the connecting pin
and reattaching the snap ring, as illustrated in
Figure 9. Reattach the cover and bolt on the two
outer poles.
6. Reattach the secondary disconnect mounting plate
with three screws and washers to the back frame.
7. Place the flexible washer on the molded pin on the
bottom of the secondary disconnect, then slide the
two feet into the slots on the mounting plate. Secure
with the two screws and standoffs, as illustrated in
Figure 6. Replace the wire bundle into the channel
on the top of the frame and secure with wire ties.
8. Insert the four interphase barriers into position,
noting the proper locations for the three different
types.
9. Slide the arc chutes into position. Place the arc
chute retainer in position and secure with the two
bolts and lock washers to the front frame. Tighten
securely.
10. Check that no wires are interfering with breaker
operation and that all bolts and nuts are tight.
Operate the breaker a few times to verify proper
operation.