Zakład Wytwórczy Aparatów Elektrycznych Sp. z o.o.
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b) The disconnector connected to work under voltage can be switched only when there is certainty that the
breaking or making current will have a negligible value, or that there will be no significant change in voltage
between the terminal elements of any pole.
c) The disconnector must not be closed until its earthing switch is open.
d) The earthing switch of the disconnector connected to work under voltage can be switched from the open
position to the closed position only when the disconnector is open and after making sure that the earthing
switch will connect at most the discharging current of capacities of the bushings, busbars, incoming sup-
plies, and short cables or overhead lines, with parameters of current and voltage given in the technical data.
5. INSPECTIONS AND MAINTENANCE
5.1. Visual inspections
It is recommended to carry out visual inspections in accordance with the regulations in force at the switchge-
ar or after each failure or short circuit. In particular should be checked:
a) condition of current path’s contacts,
b) condition of the earthing switch’s contacts.
5.2. Periodic inspections
Periodic inspections and maintenance inspections should be carried out in accordance with the regulations
in force at the switchgear. During the inspection and maintenance, the applicable regulations on the operation
of power equipment and the requirements for the safety of work of persons performing inspections must be
observed.
In particular should be checked and performed:
a) condition of contacts of current path,
b) condition of contacts of the earthing switch,
c) condition of mechanisms, bearings and fasteners,
d) correctness of achieving the limit positions,
e) condition of anti-corrosion protective coatings,
f) one should lubricate the contacts of the current path and the earthing switch contacts,
g) ball joints should be lubricated.
5.3. Spare parts and recommended maintenance materials
The use of high-quality components and operational experiences indicate a long service life of the disconnec-
tors (about 40 years). In case of damage to the disconnector due to improper assembly or operation, it is possi-
ble of for the manufacturer to repair it for a payment. The Mark-40 type disconnector has no parts that should
be replaced during normal operation in service life of the disconnector.
