Maintenance
Refer to Circuit Breaker Operator Manual.
Table 2. Periodic Maintenance and Lubrication Tasks
Sub-Assembly
Item
Inspect For
Primary Power Path
Primary Disconnects
1. Burnt or damaged fingers
2. Lubrication of contact surfaces.
3. Tightness of nuts and other locking devices
Electrical Controls
Wiring
1. Mechanical damage or abrasion
Terminals and Connectors
1. Tightness and absence of mechanical damage
Close and Trip Solenoids, Anti-
Pump Relay, Auxiliary Switches,
Secondary Disconnect
1. Automatic charging
2. Close and trip with control power
High Potential Test
Primary Circuit to Ground
and between Primary Dis-
connects
1. 60 second withstand, refer to Circuit Breaker Operator Manual
SGIM-9928 for ratings.
Control Circuit to Ground
1. 60 second withstand, refer to Circuit Breaker Operator Manual
SGIM-9928 for ratings.
Insulation
Barriers and all Insulating
Components
1. Cleanliness
2. Cracking, crazing, tracking, or other sign of deterioration
Interrupter Operator
Mechanism
Always re-install the phase barriers carefully to the original
location prior to inserting the circuit breaker in the housing.
When the contacts are mated with the switchgear’s pri-
mary stud assembly, there is forceful contact distributed
over a wide area. This maintains low current flow per in-
dividual contact finger.
Inspect the contact fingers for any evidence of burning or
pitting that would indicate weakness of the contact finger
springs.
Inspect the primary disconnect arms for physical integrity
and absence of mechanical damage.
Inspect the flexible connectors that connect the bottom
movable contacts of the vacuum interrupters to the lower
primary disconnect arms for tightness and absence of
mechanical damage, burning, or pitting.
Using a clean cloth saturated with denatured alcohol, clean
old lubricant from primary disconnects, and apply Siemens
contact lubricant (reference 15-171-370-002) in a very thin
layer.
Fastener Check
Inspect all fasteners for tightness. Both lock-nuts and re-
taining rings are used. Replace any fasteners that appear
to have been frequently removed and replaced.
Racking Mechanism
Racking mechanism is to be wiped clean, and a film of
Anderol 732 aerosol synthetic fluid grease (reference part
number 15-172-816-058) applied on the shaft surfaces,
threads and nuts.
Electrical Control Checks
Check of the Wiring and Terminals
1. Physically check all of the switchgear wiring for evidence
of abrasion, cuts, burning or mechanical damage.
2. Check all terminals to be certain they are solidly attached
to their respective device.
Electrical Close and Trip Check (Control Power Required)
A check of the breaker control circuits is performed while
the unit is still connected to the switchgear by the plug
jumper. This check is made with the breaker energized by
control power from the switchgear.
1. Once the breaker springs are charged, move the
switchgear Close/Trip switch to the Close position. There
should be both the sound of the breaker closing and
indication that the breaker contacts are closed by the
main contact status indicator.
2. As soon as the breaker has closed, the automatic spring
charging process is repeated.
3. After a satisfactory close operation is verified, move the
switchgear Close/Trip switch to the Trip position. Verify
by both sound and contact position that the contacts
are open. Completion of these checks demonstrates
satisfactory operation of auxiliary switches, internal re-
lays and solenoids.
Checks of the Spring Charging Motors of the spring charg-
ing motor are necessary.
9
1.Cleanliness
2.Lubrification of shaft surfaces.
Racking Mechanism