Siemens Static Trip III User Manual

Principles
of
OPeration
v
User
Control
iil'";lt;i*;nts
and
switches
on
the
trip
unit's,face
and
the
progiur;ing
via
the
c-ommunications
ports allow
the
user
control
of
the
trip
,n't
gy
these
means
the
user
selects
the
irr"ii"ur
valuei
and
sofiware
routines'
stored
in
the
memory
"n"ritr,
it-,urrre
to
be
used
by
the
microprocesso-rs
in
perform-
i." ir-l.ii functions.
The
selection
and
programming
process
i ;.tI;r;"".1g"'"0
i"
L"
straignt
forward
and
user
f
riendlv
to
inl*J"gt";
thi
tt","
lnt"in,l
op"eration
of
the
trip
unit
is
totally
transparent
to
the
user'
Current
Sensors
6rii".i"*ioita
for
fault
protection
and
metering
are
derived
from
special
purpose
"*["tt
sensors
mounted
in the
circuit
breaker.
These
current
sensors
are
toroidal
current
transform-
"i.-n.
prl.i"e
Oeuices
if'ey
provide
high
reliability
with
mini-
,rr'.i6.ri
"iror.
The
rated
primarv
"'ll:!l^:f
the
sensors
establish
the
maxrmum
"ontin'o"
cLrrent
rating
of
the
circuit
breaker,
The
rated
.""6nOuty
current
for
the
sensors
is
0
5
2mnores at rated o'imutv
C'it"nt
Atl
the
sensors
used
with
Silil
fnoil,
tio
,iiLt
,,.,j""tapsulated
in
polvme'ic
material
i";;"i"Jt
ir',"
*inoingt-and
prevent
motion
during
a
short
circuit
fault
condition.
ThecurrentSenSorSprovideoperatingpoweraSwellas
"r""ni
level
data
lietetoie
wnen
tre
circurt
orgallr;1
;;ili"g
load
currents,
Static
Trip
lll
trip
urits
requrre
no
external
connections
oi
"ontror
power
to
perform
iheir
basic
overcurrent
protective
f unctions'
Protective
Fault
OPeration
il;t.ril;;i.;i;u
otiLt
o"t"tiption
of
the
process
forovercurrent
fault orotection.
lhe
pio"".r
[or
Ine
extended
protective
relaying
functions
is
very
similar'
The
current
signals
from
the
sensors
are
converted
to
digital
";[u*s-ov
i-resistor
network
and
analog
to
digital
conver-
i;.
fn/bti
in
the
trip
'"li
irt"
disital
voltases
are
stored
in
temporary
memory
and
are
used
by
the^microprocessors
in
detecting
and
procesling-o'etc"ient
conditions
and
in
metering,
The orotectron
microprocessor
reads
the
temporarily
stored
;i;:,5i;;il;"t
u.i"""'p't"t
ir'";'
values
w'tn
the
set
or
;;Yr;;
"oiiJtpo^o'ns
to
the
setting
selected
bv
the
use''
When
an
overcurrent
condition
is
detected'
the
micropro-
iu..o|.[.oti*ul."
begins
to
process
the
appropriate
protec-
l"tlr""tL".
During
t6e
Iroc'essing
of
the
protection
function'
the
microprocessor
continues
to
monitor
the
incoming
cur-
rent
level
data
lt tn"
ou"L*t"nt
condition
continues
until
thetrrocessingtscompletedandtheappropriatedelaytime
;;."";.;
I
itppi"s
command
is.tssued
by
the
mtcropro-
;;;#"
T;"
tripping"
command
from
the..microproces-
sor
causes
an
output
signaf
io
be
sent
to
a
coil
in
the
tripping
actuator,
TripPing
Actuator
When
the
circuit
breaKer
is closed'
the
tripping
actuator
is
held
* ;
"h";g;;
position
by
a
permanent
magnet
The
output
;ig;rl
ilil-in6
trip
uniiLnelgizes
a
coil
inside
the
acluator
causinq
the
nagnetrc
ti'^
to
siitt
to
a
new
path
This
releases
;h"*;i;;";
;.;rgv
of
a
spting,
also
located
inside
the
actuator'
,.O"tte.
til
"i6rit
Ot"Ir''"'"Wh"n
the
circuit
breaker
mecha-
nism
opens,
tn"
a"t'Jioi
is
automatically
reiurned
to
the
charged-and
rrero
posiliJn
oy
a
reset
mechanism
A
second
coil
inside
tfre
tripping'att'utdt
is
used
to
augment
the
holding
power
of
the
permanenimagn-et
during
high
short
circuit
con-
ditions
so
that
.truy
'ugn"tic
fietds
witl
nol
cause
unintended
;i";.;;t
;;mugn"ti'ition
while
the
trip
unit
is
in
short
time
delay
(US Patent
issued)
Current
Sensors
Tripping
Actuator
(bottom
view)

Siemens Static Trip III Specifications

General

Brand	Siemens
Model	Static Trip III
Category	Circuit breakers
Language	English