19
Siemens · 10/2014
3WL Air Circuit Breakers
3WL air circuit breakers/non-automatic air circuit breakers up to 6300 A (AC), IEC
General data
ETU76B Electronic Trip Units
Ground-fault protection Ground-fault releases "G" sense fault currents that flow to ground
and that can cause a fire in the plant. Multiple circuit breakers
connected in series can have their delay times adjusted so as to
provide graduated discrimination.
When setting the parameters for the Electronic Trip Unit it is
possible to choose between "alarm" and "trip" in the event that
the set current value is exceeded. The reason for tripping is
indicated by means of an LED when the query button is
activated.
The ETU45B and ETU76B Electronic Trip Unit versions can
be retrofitted with a ground-fault protection module. This
ground-fault protection function is integrated in ETU27B
Electronic Trip Units.
Application:
The multi-talent with graphical display for system analysis –
"CubicleBUS integrated"
Properties:
The same as ETU45B but also including
• Two protection parameter sets which can be stored
separately in the trip unit (switchover is performed by
means of external signal)
• With overload protection which can be deactivated
for use in modern drive engineering applications
• Adjustable delay of delayed short-circuit protection
up to 4000 ms
• Neutral conductor protection adjustable up to
I
N
= 200 %
I
n
• Setting of protection functions by means of Breaker Data
Adapter (BDA Plus) or via communications interface
• Graphical display of all parameters and events/curve
trends
• Graphics display with high contrast, backlit display, and
sleep mode.
Technical details, see the table "Functional overview of the
electronic trip 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: ground-fault module
GFM AT 45B ground-fault module
GFM AT 55B-76B ground-fault module
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 t
g
/ t
g
Rotary switch
for setting
value,
ground-fault
protection
Ground-fault
tripped
Indicators:
2
NSE0_00962
NSE0_00964a
Field for
noting
transfer
ground-fault
detection
Fields for
noting setting
values
Ground-fault
alarm
Fields for
noting setting
values
Ground-fault
tripped
Indicators:
To Next Page
Loading...
