Description; General Characteristics; External Front View Of The Circuit-Breaker; Three-Pole Circuit-Breaker Rating Plate - ABB Emax DC L3447 Installation And Service Instructions Manual

1.

Description

1.1

General characteristics

The SACE Emax DC series of circuit-breakers consists of a steel sheet structure which houses the operating mechanism, the poles and the auxiliary
parts.
Each pole is insulated from the others and contains the circuit-breaking parts, the shunt and the override protection.
The fixed version circuit-breaker has its own terminals for connection to the power circuit; in the withdrawable version the circuit-breaker comprises
the moving part of the apparatus, which is completed with a fixed part fitted with terminals for connecting to the power circuit of the installation.
The moving part and fixed part are coupled by means of special clamps installed in the fixed part.
For details about the plant application of SACE Emax DC circuit-breakers, consult the Technical Application Papers "ABB circuit-breakers for direct
current applications" (1SDC007104G0201).
1.2

External front view of the circuit-breaker

1
2
3
Fixed circuit-breaker
Fig. 1
1.4

Moving part construction characteristics

1 Supporting structure made of steel sheet
2 Current sensor for protection release
3 Terminal supporting insulating box
4 Horizontal rear terminals
5a Main fixed contact plates
5b Fixed arcing contact plates
6a Main moving contact plates
6b Moving arcing contact plates
7 Arcing chamber
Fig. 3
L3447
Model
L3728
1 PR122/DC or PR123/DC
electronic microprocessor-
based release
2 Trade mark
3 Operating and control parts of
4
the operating mechanism and
release tripped signals
4 Rating plate
8
9
10
12
11 1
Selective circuit-breaker

1.3.1 Three-pole circuit-breaker rating plate

(i.e. for upper supply)
Fig. 2a

1.3.2 Four-pole circuit-breaker rating plate

(i.e. for lower supply)
Fig. 2b
7
6b
6a
5b
5a
4
2
3
12 13
8 Terminal box for the fixed version-Sliding contacts for the withdrawable version
9 Protection release
10 Circuit-breaker closing and opening mechanism
11 Closing springs
12 Spring loading geared motor (on request)
13 Lever for manually loading the closing springs
14 Racking-out device (only for withdrawable circuit-breakers)
15 Service releases (shunt closing release, shunt opening release, undervoltage
release)(on request)
Apparatus
Doc. No.
Upper supply
Lower supply
15
14
Emax DC
1SDH000635R0002
Scale
Page No.
5/108