15
5.2 Interlocking
5.2.1 Mechanical
Interlocks
•
Each operation procedure must
be duly carried out (at one of the
both possible end positions) prior
to commencing the next opera-
tion.
•
Simultaneous operation of interlo-
cking levers is not possible!
•
Crank handle for disconnector or
earthing switch operation can be
removed only, if belonging drive
mechanism has reached its end
position.
•
Earthing switch can only be
moved into ON postion if circuit
breaker spring is charged. (The
circuit- breaker is switched ON
automa tically after reaching the
earthing position , see sect. 5.3.)
Reverse actuation during the
switching operation is prevented.
Each actuation of the earthing
switch must be performed to its
end.
•
Circuit breaker cannot be swit-
ched ON (close) if:
- crank handle for disconnector or
earthing switch operation
has not been removed
- interlocking lever is actuated
(Means: Circuit breakers mecha-
nical push button ON (close),
and its electrical remote control
are blocked. This applies for bus
section panels circuit breakers as
well.)
5.2.2 Electromechanical
interlocks
In addition to mechanical interlocking
electro-magnetic blocking coils are
used for realization of interlocking:
- between adjacent panels within
a switchboard (for example
busbar earthing)
- between panel and external
located panel (for example
between earthing switch incomer
and earthing switch of infeeding
high voltage panel)
- between panel‘s switching
device and a solenoid switch
located in its low voltage cabinet
Number of blocking coils and their
location depend on switchboard‘s
interlocking configuration and can be
taken from the associated low volta-
ge schematics.
5.2.3 Key locking of
mechanical
operation
Optionally two alternatives are availa-
ble to lock mechanical (manual) ope-
ration of circuit breaker, ON (close),
disconnector and earthing switch.
A label sticked close to key locking
points to a incomplete interlocking
scheme.
Important!
Depending on switchboard‘s
interlocking configuration the
key locked operation is sup-
posed to be applied under special
circumstances only.
Alternative 1:
Central key locking featuring a
cylinder lock.
Turning a key means moving a plate
which prevents to press of circuit
breaker ON (close) push button.
(Blocking of circuit breaker OFF
(trip) on special request only.)
Furthermore opening to put crank
handle for disconnector and earthing
switch operation is blocked.
Alternative 2:
Padlocking
A padlockable cover is installed to
enable padlocking of circuit breaker
on (close) push button (device for
circuit breaker OFF (trip) supplied on
special request only).
Padlockable interlocking levers for
disconnector and earthing switch are
fitted.
Warning!
Provision of complete
interlocking may be
ensured by electrical
operation only.
Warning!
Before operating
switchgear refer to
specific low voltage
schematics first!
0,5
SF6
bei 20°C
KL 1.0 bar
-0,5
-1,0
0
1,0
1,5
Attention!
No interlocks are effective
in case of manual actuation
1
2
Fig. 5.2
Alternative 1: Central Key Locking
1 Mechanical lock-out mechanism with
cylinder lock
2 Information plate (enlarged)
Mechanical lock-out mechanism
pad lockable (optional)
Fig. 5.3
Alternative 2: Padlocking
1 pad lockable lid for push button
2 pad lockable lever
1
2