GE SF6, Instruction Manual

Page: 175 / 300

Maintenance
Maintenance plan
GE Information
08- 2016 L51- 004EN/07
7/8
Detail of maintenance operations , continued
Electrical densimeter
thresholds
Check the electrical contact SF
6
densimeter thresholds.
If the values found are outside required tolerances replace the densimeter.
Tightening
of mountings
Check and adjust, with a torque wrench, the tightening torques of screws on
sub- assemblies not subjected to gas pressure. The tightening torques are
given in paragraph ”Tightening torques”.
Relay operation
Check relay operation by executing the following circuit- breaker sequences:
- closing lock- out,
- automatic opening (where applicable),
- anti- pumping.
Tightening
LV terminals
With the electric cubicle out of service, check that the connectors and tips of
conductors are tightened correctly and check the torque of connection
mountings.
Tool used: 4 mm diameter screw driver, for terminals of the ”Entrelec” type (for
example).
CAUTION: SCREWS ON TERMINALS MUST NOT BE
OVER- TIGHTENED.
Insulating envelopes
Check the condition of insulating envelopes, these should be free from impact
marks, splintering, cracks, dust deposits, pollution etc...
If necessary, clean these using a dry rag.
If anomalies are found contact:
Grid Solutions, After- sales Service in order to change the defective parts.
Interrupting
chambers
Check the condition of interrupting chambers. This operation necessitates
complete dismantling of the interrupting chamber to gain access to the
elements to be inspected and should obligatorily be performed by Grid
Solutions, After- sales Service - to be contacted before all operations of this
kind, preferably at the maintenance planning stage.