IB 6.2.11.1-2C
Page 8
ABB
(Continued from page 4)
Manual Close Lever (Figure 1, Item 12).
The manual
close lever is provided on all circuit breakers to provide
a safe means of closing the breaker without control
power. The lever is provided with a hole through which
a lanyard should be attached for closing the breaker at
a safe distance .
Racking Mechanism.
The racking mechanism is used
to move the circuit breaker to any one of its three
p o s i t i o n s : " C O N N E C T E D " , " T E S T ” , o r
“DlSCONNECTED." All of these positions are
attainable with the cubicle door closed or opened. The
breaker can be closed only when the drawout lever (11,
Figure 1) is up. When up, the racking crank (8, Figure
1) cannot be turned. The circuit breaker must be in the
"OPEN" position before lever (11, Figure 1) can be
pushed down. In order to move the circuit breaker from
one position to another, the lever must be pushed down
and the crank turned; once turning begins, the lever will
stay down until another position is reached and the
lever will snap up, preventing additional turning, until
the lever is again pushed down.
When the padlocking device is locked, the lever (11) is
locked in the up postion preventing movement of the
racking mechanism.
There is a label (17, Figure 1) on the right side of the
breaker escutcheon to show breaker position when the
swichgear door is closed.
CIRCUIT BREAKER INTERNAL COMPONENTS
For electrically operated (EO) circuit breakers, the
Operating Sequence section illustrates the function of
the following devices. Electrical characteristics can be
found in Table 2.
Solid State Control Device (SSCD)
- The SSCD is
mounted on the lower-left portion of the operating
mechanism of EO circuit breakers, and controls the
electrical closing functions of the breaker. The “anti-
pump” feature of the SSCD prevents a second
electrical closing until the first closing signal is
released. For example, if the breaker is closed
electrically and the signal is maintained, the SSCD will
not permit the breaker to be closed electrically again
after a trip until the electrical close signal is released.
Shunt Trip
- The shunt trip is standard on EO breakers
and optional on MO breakers. When energized, it
releases the stored energy of the contact and opening
springs causing the circuit breaker to open.
Close Coil
- The close coil is standard on EO breakers.
When energized, it releases the stored energy of the
closing springs causing the circuit breaker to close.
Closing Spring Charging Motor
(Electrically
Operated Breakers only) - When the motor disconnect
switch is ON, the charging motor is energized
automatically by internal limit switches to charge the
closing springs electrically.
Closing Spring Check Switch (CSCS)
- There are
two CSCS’s: one automatically disconnects the power
to the charging motor when the closing springs are fully
charged; the other sends spring charge information to
the SSCD.
Auxiliary Switches
- The integral auxiliary switch is
standard on EO breakers and MO breakers with shunt
trip, and optional on MO breakers without shunt trip.
The standard configuration contains the four "a" and
Figure 2 - Electrical Characteristics of Control Devices
Nominal Control
Voltage
Average
Charging
Motor
Current*
Shunt Trip or
Close Coil
Current
Closing
Circuit
Voltage
Range
Shunt Trip
Circuit
Voltage
Range
Recommended
Control Fuse Size
120VAC (60 Hz)
10A
6.5A
104-127
104-127
10A
240VAC (60 Hz)
5A
1.2A
208-254
208-254
10A
48VDC
25A
3.1A
38-56
28-56
15A
125VDC
10A
1.3A
100-140
70-140
10A
250VDC
5A
0.7A
200-280
140-280
10A
* Approximate steady state values; momentary in-rush currents are approximately 6-8 times these values
Table 2