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Testing
I
General
Static
Trip
lll
trip devices can
be
f
ield
tested
either
with primary
current through the breaker
or
with secondary current
applied
directly
to the
trip
device. The ease
of
testing
with
secondary
current
is one of the
advantages
of
these devices.
With
comparatively inexpensive and readily available
equipment,
it
is
possible to
demonstrate
that the tripping
system
will
open
the breaker and verify that the device conforms to the pub-
lished time-current curves.
However,
field testing cannot
be
expected to be
as
accurate
as
factory calibration.
Therefore
slight
discrepancies
between
f
ield tests and
factory
calibration
can be
regarded
as
normal,
lf
large deviations
or
improper
operation should
occur,
it is
recommended that your Siemens
Energy
&
Automation
office be contacted for
advice,
Secondary Current
Testing
Portable
test set
PTS4
is
available
for
secondary
current
testing
and
is
designed
to
plug
into a
standard
.1
20
volt outlet.
With
this test
set, Static
Trip
lll
trip devices can
be
tested
by
themselves,
or on
a
circuit
breaker outside
the cubicle,
or
inside the
cubicle
with the breaker
in
the
TEST
or
DISCON-
NECTED position.
A
training videotape
is
available which
shows proper operation
of the
PTS4
test set
(see Ordering
lnformation section).
Portable Test Set
PTS4
There
is a
terminal
block
on
the
circuit
breaker just above the
trip device.
This
terminal block
accepts
a
plug
from the
test set
when testing with the device
on
the breaker, Make
all
connec-
tions
with power
removed from the
test
set.
When
testing with
the
Static
Trip
lll
device
off the
circuit
breaker,
connections
must be made to the
spade type
termi-
nals
of the
connecting
strip.
Making these connections
in-
volves
the
risk of
shorting between clips which can damage the
device. To avoid this,
the
PTS4
test set
includes a
terminal
block
for the
connecting
strip from
the
trip device similar
to
the
one
on the circuit
breaker
so
that
the spade
terminals
are
properly
isolated. The
output of
the
test set is
internally con-
nected
to the
terminal
block.
Static
Trip
lll
devices
have
two
LEDs
(Light
Emitting Diodes)
mounted
on the
front panel, One
of
these
indicates
Long Time
Pickup and the
other indicates
Short Time or
Ground
Pickup.
Unlike the earlier model of
trip
devices no connections
are
required
to
indicate when
pickup
occurs. These
LEDs also
operate during
normal
operation
on
the
breaker, and
are
useful
in
indicating
when the
long
time current setting may
be set
too
low.
Test
Connections
Current
is
supplied
to
terminals
1
and
5 to
test
phase
1
,2
and
5
to
test
phase 2; 3 and 5 to
test
phase 3;
and
4
and
5
to test
the ground circuit
on
devices with ground
fault
tripping.
For
secondary
current
testing
a
circuit
breaker
is not
needed
lf
the
device
is
mounted
on
a
circuit
breaker
it is
not
necessary
to close the
breaker,
Long Time Pickup Test
Set
ihe
Long Time Current Setting
on
.5.
Move
the
switch
above
the
LED
timer readout
on
the
PTS4
to "Static
Trip lll Long
Time" and select
the
phase
to
be
tested.
Raise
the current
slowly
untilthe
long
time
pickup
LED
is
illuminated.
This
should
occur
between
.25
and
.30
amperes (or
between
the
setting
value
and
12O%
of the setting value), as shown in Table
1.
Decrease
the
current slightly and
the LED
should
go
out
When
the
LED is
illuminated
continuously
the device
will eventually
time
out.
The Long Time
circuits
calculate
the
true
RMS
value.
This
produces
a noticeable time delay (about
3 to 4
seconds)
from the time the current reaches the
pickup
point
to
the time
pickup
is
indicated
by
the
LED.
Repeat the
test
for the
other available settings and compare
to the
values
in
Table
1
below.
The current values for secondary testing
of
Static
Trip lll
Long
Time
function
are
given
in
Table
1
below.
Table
1
Long Time Secondary Pickup Current
Current
Setting
.50 .55
.60
.65
.70 .75
.80
.85
.9( .95
1.0
Secondary
Amperes
I\,4
i
n
25
275 .30
323
.40
425
4a
.475 50
lVIax
30
.330
.10
.390
42
450
48
510
54
.574
.60
v
29

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