Siemens GMSG Instruction Manual page 12

Installation checks and functional tests
Figure 4: Manual charging of the
closing springs
12
The portion of the racking-mechanism
shaft visible is cylindrical, and the shoulder
of the racking-mechanism shaft is hidden
by a shroud until the engagement
procedure starts. The square socket-end of
the crank will only engage the shoulder of
the shaft if it is aligned properly.
The suggested procedure to engage the
racking mechanism is as follows:
1. The circuit breaker must be OPEN. (The
racking shroud cannot be moved if the
circuit breaker is CLOSED.)
Note: For arc-resistant type GM-SG-AR
switchgear, if control power is not
available and the circuit breaker
compartment door is closed, the circuit
breaker can be opened manually. To open
the circuit breaker manually with the door
closed, insert the pushrod in the aperture
(receptacle) in the front door for opening
the circuit breaker. Push the rod against
the open pushbutton on the circuit
breaker. The circuit breaker should open.
The circuit breaker position indicator will
change from CLOSED to OPEN, and this
change can be observed through the
viewing window included in the circuit
breaker compartment door.
2. Hold the socket-end of the crank in one
hand and the crank handle in the other
hand.
For arc-resistant type GM-SG-AR
switchgear, rotate the racking access
cover to enable insertion of the racking
crank.
3. Place the socket over the end of the
racking-mechanism shaft. Align the
socket with the shoulder on the
racking-mechanism shaft.
Note: If the socket is not aligned, the
socket will not be able to engage the
shoulder of the racking-mechanism shaft.
4. Once alignment is achieved, firmly
push the crank and socket assembly
toward the racking mechanism.
5. When properly engaged, the crank
should remain connected to the
racking mechanism. If the crank does
not remain in position, adjust the
spring plungers clockwise one-half
turn. This will increase the contact
pressure of the spring plunger.
6. To remove the crank, pull the assembly
off of the racking-mechanism shaft.
Note: If the effort to rack the circuit
breaker increases considerably during
racking, or if turning of the racking crank
requires excessive force, stop racking
immediately. Do not try to force the
racking crank to rotate, or parts of the
circuit breaker or racking mechanism could
be damaged. Determine the source of the
problem and correct it before continuing
with racking.
Physical inspections
1. Verify the rating of the circuit breaker is
compatible with both the system and
the switchgear.
2. Perform a visual-damage check. Clean
the circuit breaker of all dust, dirt and
foreign material.
Manual-spring charging check
1. Insert the manual-spring charging
crank into the manual-charge handle
socket as shown in Figure 4: Manual
charging of the closing spring. Turn the
crank clockwise (about 48 revolutions)
until the spring condition indicator
shows the closing spring is CHARGED.
2. Repeat the spring discharge check.
3. Verify the springs are DISCHARGED and
the circuit breaker primary contacts are
OPEN by indicator positions.
As-found and vacuum-integrity check
tests
Perform and record the results of both the
as-found insulation test and the vacuum-
integrity check (dielectric) test. Procedures
for these tests are described in the
Maintenance section of this instruction
manual on pages 36-52.