Ground Fault Protection - Siemens SENTRON 3WL Reference Manual

3WL Air Circuit Breakers/Non-Automatic Air Circuit Breakers up to 6300 A (AC)
ETU76B solid-state release
Mechanical RESET
for reclosing lockout
and mechanical
tripped indicator
Indicators:
Overcurrent release
activated
Overload alarm
COMMUNICATION
EXPANDED
Indicator: cause of release
Rating Plug
Rated current module
Option: earth-fault module
Fields for noting
setting values
Test pushbutton
Query pushbutton
NSE0_00960b
Ground-fault protection
Selector for
ground-fault
detection
1
Rotary switch
for setting
g TRIP ALARM
value,
G A
ground-fault
B
protection
C
D
OFF
E
Rotary switch
for setting value
ground-fault alarm
GFM AT 45B ground-fault module
Field for
noting
transfer
1
g
ground-fault
detection
ALARM
1
=
A
g
TRIP
1
=
A
g
Fields for
noting setting
values
GFM AT 55B-76B ground-fault module
Option: safety lock
prevents pressing of
reset button after
overcurrent release
ETU76B
Graphical display
Indicator: fault in
overcurrent release
Control keys for setting
he release parameters
Indicators:
Ground-fault alarm
Ground-fault tripped
Fields for noting
setting values
Clear pushbutton
Test socket
Indicators:
Ground-fault
alarm
GFM AT 45B
Ground-fault
tripped
J 1 J
ALARM 2
(s)
g g
.5 .1
.4 .2
TRIP
.3 .3
.2 .4
Rotary switch
.1 .5
for setting
NSE0_00962a
value, ground-
fault protection delay
2
J /1 J
g g
Indicators: Ground-fault
alarm
GFM AT 55B-76B
Ground-fault
tripped
ALARM
1 J
2
TRIP
J
= ms
g
Fields for
NSE0_00964a
noting setting
values
3WL Air Circuit Breakers
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 = 200 %
I N 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".
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.
General data
Siemens · 2009 19