Description
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Revision 06 • INSTALLATION AND OPERATING INSTRUCTIONS • 8DB10 • 864-5091.9
10
Disconnector and three-position disconnector
Function of three-position
disconnector
Busbar system 1 is equipped with a the three-position disconnector which combines the
functions of a disconnector and an earthing switch. It is designed for no-load operation only.
Function of disconnector
A disconnector is installed in busbar system 2. It is designed for no-load operation only.
The disconnector has a work-in-progress earthing contact for maintenance work,
which cannot be operated during normal operation.
ATTENTION
The work-in-progress earthing contact of the disconnector in busbar system 2 is designed for
maintenance work at the three-position disconnector in busbar system 1 in de-energized
condition only.
➭ Before switching to the work-in-progress earthing contact, always contact your regional
Siemens representative.
Fig. 7:
8DB three-position disconnector for busbar
system 1 and three-position disconnector
for busbar system 2
①
Fixed contact of busbar,
busbar system 1
②
Fixed contact of busbar,
busbar system 2
③
Work-in-progress earthing contact
for system 2
④
Moving contact for
system 2 in OPEN position
⑤
Bushing
⑥
Fixed contact for
READY-TO-EARTH, system 1
⑦
Moving contact for
system 1 in OPEN position