Zakład Wytwórczy Aparatów Elektrycznych Sp. z o.o.
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c) The disconnector cannot be closed until its earthing switch has been opened.
d) Disconnector earthing switch can be manueovered from open to close position only:
•
If the disconnector is in open position,
•
After ensuring that earthing switch will be working under discharging current of the bushings, rails, in-
coming supplies, short cables and power lines capacities, with current and voltage parameters specified
in technical data.
5. INSPECTIONS AND MAINTENANCE
5.1. Visual inspections
It is recommended to carry out visual inspections in accordance with rules being in force in switchgear or after
each failure or short circuit. Check in particular:
a) condition of current path’s central contacts,
b) condition of earthing switch’s contacts.
5.2. Periodical check-ups
In order to ensure continuous and failure-free operation of disconnectors, it is necessary to perform periodic
check-ups. While the internal regulations in force in the distribution centre do not oblige to more frequent main-
tenance, inspections are required in accordance with the following schedule:
•
Periodic inspection- after 5 years of operation or after 1000 operation cycles;
•
General inspection of earthing switch’s contacts.
During inspection and maintenance, the applicable regulations for the operation of energy devices and the re-
quirements determining the safety work of the inspectors must be obeyed.
The scope of activities to be performed during each maintenance is as follows:
a) Periodical inspection:
•
Check condition of current paths central contacts;
•
Check condition of earthing switch contacts;
•
Check the correctness of taking the end positions;
•
Check the condition of mechanisms and bearings
•
Check tightness of screw connections and fasteners;
•
Clean the outer surfaces of insulators;
•
Check the condition of protective coating and parts protecting against corrosion;
•
Lubricate the current path contacts and the earthing switch contacts (not required for disconnectors
equipped with graphite AgC contacts)
1)
;
•
Perform thermal inspection of the disconnector at rated current
2)
;
