3WL Air Circuit Breakers
19
Siemens · 2009
3WL Air Circuit Breakers/Non-Automatic Air Circuit Breakers up to 6300 A (AC)
General data
ETU76B solid-state release
Ground-fault protection Ground-fault releases "G" sense fault currents that flow to ground
and that can cause fire in the plant. Multiple circuit breakers con-
nected in series can have their delay times adjusted so as to pro-
vide graduated discrimination.
When setting the parameters for the solid-state release it is pos-
sible to choose between "alarm" and "trip" in the event that the
set current value is exceeded. The reason for tripping is indica-
ted by means of an LED when the query button is activated.
The ETU45B and ETU76B solid-state release versions can be re-
trofitted with a ground-fault protection module. This ground fault
protection function is integrated in ETU27B solid-state releases.
Application:
The multi-talent with graphical
display for system analysis –
"CubicleBUS integrated"
Features:
The same as ETU45B but also
including
• Two protection parameter sets
which can be stored separately
in the release (switchover is per-
formed by means of external si-
gnal)
• With overload protection which
can be deactivated for operation
in modern drive technology
• Adjustable delay of
delayed short-circuit protection
up to 4000 ms
• Neutral conductor protection ad-
justable up to
I
N
= 200 % I
n
• Setting of protection functions by
means of Breaker Data Adapter
(BDA) or via communications in-
terface
• Graphical display of all
parameters and events/
curve trends
• Graphics display with high con-
trast, backlit display, and sleep
mode
For technical details see the table
"Functional overview of the
solid-state release system"
under "Technical specifications".
Rating Plug
NSE0_00960b
ETU76B
Option: safety lock
prevents pressing of
reset button after
overcurrent release
Mechanical RESET
for reclosing lockout
and mechanical
tripped indicator
Overload alarm
Overcurrent release
activated
COMMUNICATION
EXPANDED
Indicators:
Query pushbutton
Test pushbutton
Fields for noting
setting values
Indicator: fault in
overcurrent release
Test socket
Clear pushbutton
Ground-fault tripped
Indicators:
Fields for noting
setting values
Ground-fault alarm
Control keys for setting
he release parameters
Indicator: cause of release
Rated current module
Graphical display
Option: earth-fault module
GFM AT 45B ground-fault module
GFM AT 55B-76B ground-fault module
1
ALARM
ALARM
.5
.4
.3
.2
.1
.1
.2
.3
.4
.5
J
g
(s)
1
2
J
g
NSE0_00962a
GFM AT 45B
TRIP
G
A
B
C
D
E
OFF
TRIP
g
Selector for
ground-fault
detection
Rotary switch
for setting value
ground-fault alarm
Ground-fault
alarm
Rotary switch
for setting
value, ground-
fault protection delay
J
g
/
1
J
g
Rotary switch
for setting
value,
ground-fault
protection
Ground-fault
tripped
Indicators:
2
ALARM ALARM
NSE0_00964a
GFM AT 55B-76B
TRIP
TRIP
g
A
A
ms
1
2
J
1
g
1
g
1
g
J
=
=
=
Field for
noting
transfer
ground-fault
detection
Fields for
noting setting
values
Ground-fault
alarm
Fields for
noting setting
values
Ground-fault
tripped
Indicators:
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