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PowlVac® CDR 27kV & 38kV Vacuum Circuit Breaker
IB-65020A
Recommended Renewal Parts and Replacement Procedures
1) Vacuum Interrupter Assembly
CAUTION
CAUTION
!
The vacuum interrupter should only be
replaced by a qualified person or a Powell
Service technician. Contact Powell for further
assistance at 1.800.480.7273.
This assembly (Figure 28, b) is located
between the upper and lower primary
disconnecting contacts (Figure 2, a & d).
Refer to Figure 27, Vacuum Interrupter
Assembly Drawing, while performing the
following instructions. The numbers in
parenthesis after the part name coordinate
with the part numbers on the vacuum
interrupter assembly drawing.
a. Disassembly
i. Ensure all operating springs are
discharged and the circuit breaker is
open.
ii. With the circuit breaker in the OPEN
and DISCHARGED position, loosen
both of the socket set screws (41)
from the primary conductor (1).
iii. Using the primary disconnect
removal tool (Catalog # 43397H01)
and at least a grade 8, ¼ - 20 x 3-¼”
bolt, remove the primary conductor
(1).
iv. Remove the electrostatic shield (16).
v. Remove the single button head cap
screw (36) that restricts access to
one of the hex head cap screws (32).
vi. Remove the remainder of the hex
head screws (32), to allow the
vacuum interrupter (3) to move to
the CLOSED position.
vii. With a pencil, trace an outline of
the bottom bus support (7) on the
high voltage housing (11). During
reassembly, the outline will enable
proper alignment of these devices.
viii. Remove both hex head cap screws
(23) and loosen the hardware from
the hex head cap screw (24).
ix. Carefully loosen and remove 3 of 4
button head cap screws (20). Notice
that shims (approximately ⁵/₈” OD,
and ³/₈” ID) may be located behind
the bottom bus support (7). If shims
are used, they are held in place by
the button head cap screw (20).
Note:
It is important to document the
location and size of the shims to
enable proper reassembly of the
bottom bus support (7).
x. Remove the last of the 4 button
head cap screws (20) described in
step ix
and remove the combined
bottom bus support (7) and the
lower bus connector (2). It is
important to hold the vacuum
interrupter (3) securely to avoid
allowing the pushrod to tilt enough
to strike the circuit breaker frame.
The pushrod will break if it hits the
frame with sufficient force.
xi. While holding the front terminal
clamp (10) to prevent it from tilting,
loosen the socket head bolt (35).
Unscrew the vacuum interrupter
(3) and the assembly from the
operating pushrod (4). Use care
to avoid allowing the operating
pushrod (4) to hit the circuit breaker
frame. The pushrod will break if it
hits the frame with sufficient force.
xii. Place the vacuum interrupter (3)
and the front terminal clamp (10)
on a level surface such as a table,
to remove the socket head bolt
(35). Before unscrewing the front
terminal clamp (10), observe and
