16
Instruction Booklet
IB02201004E
Effective October 2017
Revision #4
Instructions for installation, operation, and
maintenance of 38 kV type VacClad-W,
150 BIL switchgear indoor housings
EATON
www.eaton.com
2 .
Primary disconnecting contacts and primary contact
insulating tubes
Remove each breaker from its compartment . De-energize the
primary circuits and expose the primary contacts and their sup-
ports by manually opening automatic safety shutters . Wipe clean
with a cloth moistened in a non-flammable solvent . Inspect for
abnormal wear or overheating . Discoloration of the surfaces is
not harmful unless corrosion due to atmospheric conditions is
severe, resulting in deposits on the surface . Check each breaker
while it is out of the housing for all items recommended in the
instruction book applying to that particular type of breaker .
3 .
Other disconnecting contacts
Inspect all secondary disconnecting contacts, such as those on
auxiliary drawout assemblies, for abnormal wear, fatigue, or over-
heating . Replace if necessary . Otherwise treat the same as the
main disconnecting contacts above .
4 .
Control contactors
Contacts should be inspected and dressed or replaced when the
surface becomes pitted . Unless repetitive duty has been experi-
enced, little attention should be required .
5 .
Instruments, relays, and other panel mounted devices
Individual devices should be maintained according to the specific
instructions supplied for each device . Remove all relay covers
and inspect the interiors for dust or dirt . Relay test personnel
can easily perform this operation during periodic relay testing .
6 .
Secondary wiring
Check all wiring connections for tightness, including those at
the current and voltage transformers and at the terminal blocks
where circuits leave the switchgear . Make sure that all second-
ary wiring connections are properly connected to the switchgear
ground bus where so indicated .
7 .
Mechanical parts
Visually check and manually operate mechanical moving parts
such as the shutter, TOC and MOC switch assemblies, the posi-
tion interlock, hinged doors, and the drawout features of the
auxiliary drawout assemblies . Examine mechanical mating parts
such as the breaker secondary contacts blocks, guide rails, and
trippers . Grease the racking screw and the plunger/operating
mechanism of the MOC switch .
8 .
Ventilation
Check all grillwork and air passages for obstructions and accumu-
lations of dirt .
9 .
Battery and charging equipment (optional)
The control battery is such an important item in switchgear
operation that it must be given special periodic attention if it
is to give reliable service for a long period of time . Periodic
inspections and test are recommended in the battery supplier(s)
instructions . At the same time the battery is checked, inspect
the battery charger and remove accumulations of dust and dirt .
On all chargers having a manual transfer switch for setting the
charging rate, check carefully to be sure that the selector switch
is returned to the value appropriate for a floating charge at the
end of the periodic inspection . Serious damage to the control
battery can occur if the charger is left on a high charging rate for
an extended period of time .
10 .
Records
The condition of each switchgear unit at the time of inspec-
tion should be listed in a permanent record to become a guide
for anticipating the need for replacements or for special atten-
tion between the regular maintenance periods . Megger tests
are suggested for checking the insulation . A series of these
tests will indicate any tendency toward a reduction in dielectric
strength of the insulation . Megger readings should be taken
before and after cleaning the equipment and, where possible,
under similar conditions at successive periods . Records should
include the megger reading, the temperature, and the humidity .
The readings will vary with the extent and design of the bus
structure . In contrast with a small installation, the longer switch-
gear assemblies will have a more extensive bus structure with
a greater number of insulators and, thereby, a larger number of
parallel insulation resistance paths to ground which will tend to
decrease megger readings . This variation in insulation resistance
between different switchgear assemblies emphasizes the value
of a series of readings, which can be charted to establish a nor-
mal insulation level so that progressive weakening of the insula-
tion can be recognized .
11 .
Abnormal conditions
Local conditions such as high humidity, salt-laden atmosphere,
corrosive gases, heavy dust, or severe circuit operating condi-
tions, are considered to be abnormal . They will require more
frequent inspections .
It should be emphasized that a series of inspections should be
made at quarterly intervals until the progressive facts of the
local conditions can be analyzed to determine a schedule which
will maintain the equipment in satisfactory condition . In some
locations, conditions may be so harsh that the frequency of
maintenance will interfere with operating and production sched-
ules . In such cases, consideration should be given to the pos-
sibility of enclosing the switchgear equipment in a relatively tight
room and supplying a sufficient quantity of clean air to maintain
a positive pressure in the room . Under such conditions, main-
tenance schedules may then be established on a more normal
basis . Such an arrangement might also provide for cooling the
air where the ambient temperature is relatively high, thus further
improving operating conditions .
