Operating Mechanism; Fixed Circuit-Breakers - ABB HD4/R Installation And Operating Instructions Manual

5.3 Operating mechanism

The ESH operating mechanism with energy stored by means
of preloaded springs is used for fixed or plu-in HD/4... circuit-
breakers.
The closing springs of the ESN operating mechanism are load-
ed in the manual mode using the special removable lever.
The opening springs are automatically reloaded during the
closing operation.
If a gearmotor is installed, the closing springs are automatically
loaded after each closing operation. The shunt closing, shunt
opening and undervoltage releases allow the operations to be
carried out in the remote mode.
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2
3
4
5
6
16
Key
1 SF gas pressure signalling device (on request - only
6
for circuit-breakers with pressure switch)
2 PR521 or REF 601 overcurrent relay (on request)
3 Closing pushbutton
4 Opening pushbutton
Circuit-breaker closed indicator
5
6 Circuit-breaker open indicator
7 Medium voltage terminals
Circuit-breaker pole
8
9 Current sensors (if provided)
10 Key lock
Fixing brackets
11
12 Undervoltage release
13 Additional shunt opening release
Shunt opening release
14
15 Indicator for closing springs loaded (yellow) / discharged (white)
16 Lever for loading the closing springs in the manual mode
17 Circuit-breaker control circuit supporting terminal box
10

5.4 Fixed circuit-breakers

The fixed circuit-breaker (fig. 4) is the basic version, previously
described in sect. 5.2. There are two drilled supports in the
lower part of the structure to allow the circuit-breaker to be
fixed.
The terminal box (17) is available for the electrical connections
of the circuit-breaker's auxiliary circuits, in the front protection.
The earthing screw is located at the side of the circuit-breaker.
12
13
14
15
17
Figure 4
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7
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9
7
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