Table of Contents
Advertisement
:-
Testing
The
illumination
on
the
pickup
LED
indicates thatthe
time
delay
has
started. The
timing circuit does not
have
the time
lag
evident
in
the
pickup
indication, When the "Thermal Memory"
switch
is "Out,"
the
Long Time elements will be
cleared
each
time
the
LED
goes out;
if
the "Thermal Memory" switch
is
"1n,"
the
device
will
accumulate
the overload times
and
will treat a
series of short overloads as if
it
were one
interval. While the
overload is
below
the current setting the tlme register
slowly
resets,
so
that
if the
periods
between overloads
are
long
enough
the device will
not
triP.
Short Time PickuP Test
Set
Long Time Current Setting on
.5
and
Short
Time Pickup
on
2
Move-the switch above the
LED
timer readout
on
the
PTS-4
to "All Other
Tests" and
selectthe
phase
to
be
tested.
Raise
the
current slowly until
the
Short Time/Ground
Pickup
LED.is
illuminated. This
should be between
.50
and
.60
amperes
(or
the setting
value
and
120%
of
the setting value)
as
shown
in
Table
2.
Repeat
for
other
Short
Time settings
as
desired
Note
thatthe
circuit
breaker
maytrip
(or
PTS4test setmay
sense
trip
signal and
shut
off
power) very
quickly
after
the pick up
light
comes
on.
Note:
Do not
allow currents above one ampere
to
continue for
more
than
a
minute
at
a
time
to avoid
overheating the trip
device,
A circuit
breaker
is
provided in the
PTS4
test set
to
prevent thermal
damage from repeated
high current tests'
Table2
Short Time
Secondary Pickup
Currents
(Long Time Current
Setting
on
.5)
Select the phase
to be
tested.
Move
the switch above the
LED
timer readout
on
the
PTS4
to
"All Other Tests".
Set
the
Instan-
taneous
on 2,
increase
the
current slowly
until
the breaker
trips
and/or the
PTS4
test set timer stops. This should
occur
be-
tween
I
.O
and
1
.2
amperes,
as
shown
in
Table
3
Test the
other
pickup
settings
as
desired.
See
Table
3
for
calibrated pickup
values.
Table
3
lnstantaneous
Secondary Pickup
Currentso
O
Note
on
earl
er model trip units
wlth
ight grey
facepate,
the tolerance
for
instantaneous
pickup was
tlO%
rather
lhan
+20%l-O%
for current
pro-
duction
units.
Ground
PickuP Test
Select Static
Tiip
lll ground
test
on
the
PTS4.
Move the switch
above the
LED
timerreadout
on
the
PTS4
to "All Other Tests"'
Observe the
Short
Time/Ground Pickup
LED
This
is
the same
LED
that indicates
Short
Time pickup.
The
ground settings are
shown
in
Table 4 with their
associated test
limits.
Table
4
Ground
Fault
Secondary PickuP Currents
Short Time
Pickup
2
3
4
5
6
7
8
12
Secondary
Amperes
Nl
rn
50
75
1.00
\
.lc
1.50
175
2.AO
300
Max
hU
90
1.20
1.50
1.80
2.14
2.40
3.60
Due to
the
low
values
of
current
the
trip
device
may
not
trip the
circuit
breaker when tested with secondary current
into the
ground circuit only.
lt
may be
necessary
to
supply some phase
6urrent
in
order
to
have
suff
icient power
to release the
tripping
actuator,
The PTS4test set
provides
thisf
unction automatically'
Long Time
Delay
Test
UseIhe
high
range ammeter
setting
on
the
PTS4
test
set
l.
Move
th6 switch
above the
timer
LED readout on the
PTS4
to
"static Trip
lll
Long Time"
and
select
the
phase
to
be
tested.
2,
Close
the switch and
set the
current
to
the desired
value'
3.
Open
the switch (and close
the
circuit
breaker)
4.
Without changing
the
setting
of
the
current source, close the
switch and measure
the
time
untilthe
breaker opens
or PTS4
relay stops
timing.
Compare
the
results to the
time
current
curves,
(see
curves in
lnstallation
and Adjustment
lnstruc-
tion, page
12).
Example:
Set Long Time Current Setting
on
.5, Long
Time
Delay
on
17.
Input current at
1
5 amperes
(6-times
25)
Set
Shori Time Band
and
lnstantaneous
on
I2x.
The
timed
inter-
val
should be between 17
and 25 seconds.
lnstantaneous
TriP
Test
Pickup
for the
Instantaneous
element
is
demonstrated
by
tripping
of
the circuit
breaker
or operation
of the
targets
and
reiay
in the
portable
test
set since
immediate
trip will
be
executed.
lnstantaneous
is
calibrated
in
multiples of 0
5
ampere.
Unlike
the Short
Time Pickup
it is
not
effected
by the
current setting
of
the
Long Time element.
Note:
Do not
allow currents above one ampere
to
f
low
for
more
than a
minute,
to avoid overheating the
trip
device. A circuit
breaker
is provided
in
the
PTS4
test
set
to
prevent
thermal
damage from repeated high current
tests,
At higher
settings
some of the other circuits may time out while the current
is
being raised
to
the instantaneous
level. This
can
be
minimized
Oy
s6tting the
Long
Time Current and
Delay
and
Short Time
Pickup on their maximum settings.
On
devices
with
Targets
the Short
Circuit target should operate
when
the device operates
on its lnstantaneous or Short Time
element.
lnstantaneous
Pickup
2
4
6
I
12
15
Secondary
Amperes
1\,4
i
n
10
2.0
30
4.0
6.0
75
N,4ax
12
2.4
J,O
4.8
72
9.0
Ground Faull
Pickuo
20
30
40
50
60
Secondary
Amperes
N,4
n
09
.135
18
225
27
Max
11
165
.22
275
.33
30
Advertisement
Table of Contents
