Current In Multiples Of Long Time Setting - Siemens Static Trip III Instruction Manual

lnstallation and
Adjustments lnstructions
i
lv
d.Maximum short time delay is
a
horizontal
lineextendsfromthemaximumvalueoftheshorttimedelay
line along the .37-second time
line from
the
band to
.07
seconds, the maximum interrupting time.
maximumshorttimepickuptothemaximum Example: (12+.6)x12A%=24
instantaneous
pickup
l2.The
l2t
short time ramp delay may be added to the Time
11.The maximum instantaneous pickup
line is
a
line
corre-
Current Curve
by
using
previously presented
data,
see
sponding
to
a
value that
is
20%
greater
than the
setting.
The
Short Time Fault Protection.
Y
Current in Multiples of
Long Time
Setting
10
.1
100
1
000
1
0000
1
000
100
o
!,
o
I
ro
a
.;
E
i=
.1
.01
STEP
4
- Draw minimum-
rong
lme
prcKup
ilne
-I
STEPl-Selectlong
time setting and lon(
time delay band
,6
=u
Setting
ttttttttt
STEP 10a
- Draw maximum
long time p ckup
lrne
Long
Tlme
Delay
\\
I
.
STEP 10b
- Draw upper
limi
/
ot long time delay band
ower lrmil
ay band
of iong time de
STEP 2 -
Selecl
Qhnrt
;6
)r{
pickup
p(
;tnt
I
leference polnt, (7.2x,
10
sec), for upper
mit
of long time delay band (calculated)
te
)raw minin
pickup
iinr
l
rand
tum
td,;
Short Time
Picku p
Reference polnt (6x,
10 sec), for lower
limit
of long time delay band (given)
ll t t t t ttttt
t
STEP 10c
- Draw maximum short
time
pickup
Iine
I
STEP
6
I
short tin
--]_rrr
]TEP 5 - Selecl
;hort time dela\
I t l t i l|l
STEP 12
- Draw short tirne
l'?t
ramo delav
='th';
STEP
1Oc
short
trm(
- Draw upper
limit
ol
delav band
sl
ln
Short lime
Delay
t t|tl
'EP
7 - Select/Ca
ltantaneous pick
lcr
up
S-
of
late
line
EP
B
- Draw lower
limlt
short time delay band
STEP1l-I
instantane(
lalculate/i
lus pickup
)raw
line
maxtmum
2
15
I
nstantaneous
Pickup
||
l]ll
SI
inr
'EP
9
- Draw mrnimum
'
itantaneous
plckup
iine
/laxlmum
nterrupting
tlme
= .07
111
ttt
ec.
ry
Example Time-Current Curve
17