GE Industrial Solutions Arc Vault Protection System - Manual (Page 45)

DEH-41483 Rev. 3 Arc Vault™ Protection System
Maintaining the Switchgear
© 2011 General Electric All Rights Reserved 37
Before lubricating, remove any hardened grease and dirt
from latch and bearing surfaces with mineral spirits then
wipe with a clean rag.
CAUTION
All excess lubricant should be removed with a clean
cloth to avoid accumulation of dirt or dust.
On a drawout device, the contact surface of the disconnect
fingers should be cleaned and greased with GE lubricant
D6A15A2.
Instruments, Instrument Transformers, and Relays
Check and inspect all devices to see that they are
functioning properly. Check that all electrical connections
are tight. Check mounting of the device.
Under normal conditions, the protective relays do not
operate; therefore, it is important to check the operation of
these devices regularly. Refer to Relay Instruction Books for
detailed instructions.
Arc Vault Compartment Interiors
WARNING
De-energize equipment completely before doing
maintenance work in compartments. This includes
de-energizing any connections to outside primary or
secondary sources, such as transformers, tie lines,
etc.
1. Thoroughly clean the interior of the device and
instrument compartments. Use a vacuum cleaner and
clean rags only. Do not use steel wool or oxide papers.
Blowing with compressed air is not recommended.
2. Check indicating devices, mechanical and key
interlocks.
3. Check primary disconnecting device contacts for signs
of abnormal wear or overheating. Discoloration of the
silvered surfaces is not ordinarily harmful. These
contacts should be cleaned only by wiping with a lint-
free cloth.
4. Clean the racking mechanism and lubricate with GE
lubricant D6A15A2.
5. Before replacing the device, wipe off the primary
disconnecting device contacts. Apply a thin coat of GE
lubricant D6A15A2 to the stationary studs and to the
primary disconnects on the breaker.
BUS AREA
WARNING
De-energize equipment completely before doing
maintenance work on any devices, connections, bus
work, Arc Vault or feeder cable compartments. This
includes de-energizing any connections to outside
primary or secondary sources, such as transformers,
tie lines, etc.
Failure to de-energize equipment may result in
personal injury or death.
Inspect and check the bus area as follows.
1. Inspect the buses and connections carefully for
evidence of overheating or weakening of the insulating
supports. If bus insulation is present, remove the
molded covers over the main bus connection to expose
joints for inspection.
2. Check all connection bolts in the bus compartment and
all bracing bolts for tightness. See the Torque Table A-1
in Appendix A.
3. Vacuum and, with a clean rag, wipe the buses and
supports.
4. Visually inspect the insulation on the bars that run from
the breaker studs through the bus structure to the
cable area.
5. After cleaning, megger and record the resistance to
ground and between phases of all insulated bars and
all buses and connections. Disconnect all control
circuits before checking resistance. Do not use over a
1500-volt megger. Since definite limits cannot be given
for satisfactory insulation resistance values, a record
must be kept of the readings.
6. Weakening of the insulation from one maintenance
period to the next can be recognized from the recorded
readings. The readings should be taken under similar
conditions each time, if possible, and the record should
include the ambient temperature and humidity.
CABLE COMPARTMENT
Inspect and check the cable compartment as follows.
1. Inspect all power cable connections for signs of
overheating and tighten all connections. If severe
discoloration or if damage is apparent, remove the
damaged portion of the cable.
CAUTION
Be sure the condition which caused the over-heating
has been corrected before energizing.