Westinghouse Digitrip RMS 600 User manual

A
Instructions
for
Digitrip
RMS
600
Trip
Unit
I
.
L
.
29
-
852
-
A
Table
of
Contents
The
user
is
cautioned
to
observe
all
recommendations
,
warn
-
ings
and
cautions
relating
to
the
safety
of
personnel
and
equip
-
ment
,
as
well
as
all
general
and
local
health
and
safety
laws
,
codes
,
and
procedures
.
Page
General
Description
Protection
Information
/
General
Testing
UL
Listed
Devices
Principle
of
Operation
General
Making
Current
Release
(
Discriminator
)
Instantaneous
Override
Zone
Interlocking
Trip
and
Operation
Indicators
Readout
Display
Readout
Display
Messages
Normal
Service
After
Trip
or
Trouble
Analyzing
"
After
Trip
"
Coded
Messages
Case
1
-
Overload
Trip
Operation
Case
2
-
Instantaneous
Trip
Operation
.
Other
Cases
Test
Provisions
Protection
Settings
General
Long
Delay
Settings
Long
Delay
Time
Settings
Short
Delay
Pick
-
up
Settings
Short
Delay
Time
Settings
Instantaneous
Pick
-
up
Settings
Ground
Fault
Current
Pick
-
up
Settings
.
.
Ground
Fault
Time
Delay
Settings
Integral
Test
Panel
-
Test
Procedure
.
.
.
General
When
to
Test
Test
Provisions
Mode
of
Conducting
Tests
Control
Power
By
Not
Tripping
the
Breaker
By
Tripping
the
Breaker
Back
-
up
Battery
General
Battery
Check
Battery
Replacement
Auxiliary
Power
Module
Rating
Plug
References
Type
DS
Low
Voltage
AC
Power
Circuit
Breakers
Type
SPB
Systems
Pow
-
R
Breakers
.
..
.
Digitrip
RMS
Trip
Assemblies
Series
C
®
R
-
Frame
Molded
Case
Circuit
Breakers
1.0
1
1.1
1
1.2
1
The
recommendations
and
information
contained
herein
are
based
on
Westinghouse
experience
and
judgement
,
but
should
not
be
considered
to
be
all
-
inclusive
or
covering
every
appli
-
cation
or
circumstance
which
may
arise
.
If
any
questions
arise
,
contact
Westinghouse
Electric
Corporation
for
further
infor
-
mation
or
instructions
.
1.3
4
2.0
4
3.0
4
3.1
4
3.2
4
5
3.3
5
3.4
1.0
General
Description
5
3.5
6
3.6
1.1
Protection
6
3.6
.
1
6
3.6
.
1.1
3.6
.
1.2
3.6
.
1.3
3.6
.
1.3
.
1
3.6
.
1.3
.
2
3.6
.
1.3
.
3
The
Digitrip
RMS
600
Trip
Unit
,
illustrated
in
Fig
.
1
,
is
a
micro
-
processor
based
type
trip
unit
suitable
for
use
in
type
SPB
Systems
Pow
-
R
circuit
breakers
and
types
DS
and
DSL
low
voltage
AC
power
circuit
breakers
and
Series
C
®
R
-
Frame
molded
case
circuit
breaker
.
6
7
7
8
8
8
3.7
The
trip
unit
provides
true
RMS
current
sensing
for
proper
correlation
with
thermal
characteristics
of
conductors
and
equipment
.
Interchangeable
rating
plugs
are
provided
to
estab
-
lish
the
continuous
current
rating
of
each
circuit
breaker
.
4.0
8
8
4.1
9
4.2
9
4.3
9
4.4
The
Digitrip
RMS
600
Trip
Unit
is
completely
self
-
contained
and
when
the
circuit
breaker
is
closed
,
requires
no
external
control
power
to
operate
its
protection
systems
.
It
operates
from
current
signal
levels
and
control
power
derived
through
current
sensors
integrally
mounted
in
the
circuit
breaker
.
9
4.5
9
4.6
9
4.7
9
4.8
9
5.0
9
5.1
The
Digitrip
RMS
600
Trip
Unit
is
available
in
six
optional
pro
-
tection
models
.
Each
trip
unit
may
be
equipped
with
a
maxi
-
mum
of
five
phase
and
two
ground
(
time
-
current
)
adjustments
to
meet
specific
application
requirements
.
These
protection
models
include
the
following
types
which
are
further
illus
-
trated
in
the
nameplate
examples
shown
in
Fig
.
2
.
10
5.2
10
5.3
11
5.4
11
5.4
.
1
11
5.4
.
2
5.4
.
3
11
13
6.0
Identifier
Type
Protection
Figure
13
6.1
13
6.2
(
LI
)
Long
Time
/
Instantaneous
Long
Time
/
Short
Time
Long
Time
/
Short
Time
/
Instantaneous
Long
Time
/
Instantaneous
/
Ground
Long
Time
/
Short
Time
/
Ground
Long
Time
/
Short
Time
/
Instantaneous
/
Ground
2.1
13
6.3
(
LS
)
2.2
13
7.0
(
LSI
)
2.3
14
8.0
(
LIG
)
2.4
14
9.0
(
LSG
)
(
LSIG
)
2.5
9.1
2.6
14
14
9.2
14
9.3
1.2
Information
/
General
9.4
14
In
addition
to
the
protection
function
,
the
Digitrip
RMS
600
Trip
Unit
is
equipped
with
a
four
-
digit
,
alpha
-
numeric
readout
dis
-
play
,
three
phase
and
one
ground
(
when
supplied
)
current
pointer
green
LEDs
along
with
a
stepping
pushbutton
as
illus
-
trated
in
Figs
.
1
and
2
.
A
Power
/
Relay
module
is
included
to
provide
control
power
for
operating
the
readout
display
and
internally
mounted
signal
relays
.
The
signal
relays
provide
contacts
for
three
remote
mode
of
trip
indicators
(
long
delay
,
short
circuit
,
ground
fault
)
and
a
High
-
Load
remote
alarm
.
WARNING
DO
NOT
ATTEMPT
TO
INSTALL
OR
PERFORM
MAIN
-
TENANCE
ON
EQUIPMENT
WHILE
IT
IS
ENERGIZED
.
DEATH
OR
SEVERE
PERSONAL
INJURY
CAN
RESULT
FROM
CONTACT
WITH
ENERGIZED
EQUIPMENT
.
ALWAYS
VERIFY
THAT
NO
VOLTAGE
IS
PRESENT
BEFORE
PROCEEDING
WITH
THE
TASK
,
AND
ALWAYS
FOLLOW
GENERALLY
ACCEPTED
SAFETY
PROCEDURES
.
THE
WESTINGHOUSE
ELECTRIC
CORPORATION
IS
NOT
LIABLE
FOR
THE
MISAPPLICATION
OR
MISIN
-
STALLATION
OF
ITS
PRODUCTS
.
Red
LED
indicators
are
provided
on
the
face
of
the
trip
unit
to
indicate
the
mode
of
an
automatic
trip
operation
as
well
as
a
High
-
Load
alarm
.
Green
LED
indicators
are
provided
to
indicate
the
operational
status
of
the
trip
unit
and
the
status
of
the
back
-
up
battery
mounted
in
the
rating
plug
.
Effective
May
,
1989
Supersedes
I
.
L
.
29
-
852
dated
January
,
1988
Courtesy of NationalSwitchgear.com

2
Fig
.
1
Typical
Dig
it
rip
RMS
600
Trip
Unit
with
Rating Plug
Installed
Phases
-
kA
IA
g
)
Values
!
B
g
>
lc
®
Phases
-
kA
'
A
g
)
'
B
g
)
lc
g
)
Ul
Values
Westinghouse
Digital
Protection
Digitrip
RMS
600
Westinghouse
Digital
Protection
Digitrip
RMS
600
[
Cell
No
.
g
)
High
Load
Cell
No
.
g
)
High
Load
Step
Step
NP
256
P
655
H
21
Made
m
U
S
A
'
/
3
N
Lithium
Battery
Only
NP
256
P
655
H
21
Made
in
U
S
A
'
/
3
N
Lithium
Battery
Only
Long
Delay
Setting
Long
Delay
Time
[
4
JSec
-
1
—
'
At
6
ln
Long
Delay
Time
rrisec
-
1
—
'
At
6
ln
Long
Delay
Setting
rn
'
n
2
2
0
0
0
0
Short
Delay
Pickup
Breaker
Trips
In
6
T
Test
Amps
0
Breaker
Trips
In
6
T
Test
Amps
0
v
0
'
n
0
0
Short
Delay
Time
0
Sec
o
o
*
=
m
Test
Test
0
o
o
Inst
.
Trip
Trip
Upn
Reset
Reset
0
Unit
Unit
<
2
*
Status
Status
Override
/
Discriminator
Inst
.
NP
256
P
656
H
11
NP
256
P
656
H
01
Fig
.
2.2
Long
TimelShort
Time Protection
(
LS
)
Nameplate
Fig
.
2.1
Long
Time
/
lnstantaneous
Protection
(
LI
)
Nameplate
Courtesy of NationalSwitchgear.com

3
®
Phases
-
kA
IA
g
Values
!
B
g
lc
®
Phases
••
kA
lA
g
IB
g
1
C
g
IG
g
U
1
Westinghouse
Digital
Protection
Digitrip
RMS
600
Values
Westinghouse
Digital
Protection
Digitrip
RMS
600
(
Cell
No
g
High
Load
Cell
No
g
High
Load
Step
Step
NP
256
P
655
H
21
Made
m
U
S
A
V
-
j
N
Lithium
Battery
Only
NP
256
P
655
H
21
Made
in
U
S
A
Vs
N
Lithium
Battery
Only
Long
Delay
Time
[
71
Sec
-
1
—
'
At
6
ln
Long
Delay
Time
[
71
Sec
-
1
—
'
At
6
ln
Long
Delay
Setting
m
'
n
Long
Delay
Setting
m
'
n
2
2
0
0
0
0
Short
Delay
Pickup
Breaker
Trips
In
6
T
Test
Amps
0
'
n
Breaker
Trips
In
6
T
Test
Amps
GO
ln
Gnd
.
Fault
Pickup
0
'
n
0
0
Short
Delay
Time
CDSec
0
oo
*
=
pt
*
=
pt
\
Test
Test
\
0
s
Gnd
.
Fault
Time
PH
Sec
oo
Inst
.
Inst
.
Trip
Trip
ln
H
'
n
Reset
Reset
0
0
0
&
>
Unit
Unit
<
2
>
Status
Status
Inst
.
Gnd
.
Inst
.
NP
256
P
656
H
21
NP
256
P
656
H
51
Fig
.
2.4
Long
Time
/
Instantaneous
Ground
Protection
(
LIG
)
Nameplate
Fig
.
2.3
Long
Time
/
Short
Time
/
lnstantaneous
Protection
(
LSI
)
Nameplate
®
®
Phases
-
kA
|
A
g
Values
!
B
g
>
lc
(
g
)
IG
g
)
Phases
-
kA
lA
<
g
)
'
B
g
1
C
<
g
)
IG
g
u
|
Westinghouse
Digital
Protection
Digitrip
RMS
600
Westinghouse
Digital
Protection
Oigitrip
RMS
600
Values
Cell
No
g
High
Load
Cell
No
g
High
Load
Step
Step
NP
256
P
655
H
21
Made
in
USA
'
/
3
N
Lithium
Battery
Only
NP
256
P
655
H
21
Made
in
U
S
A
'
/
3
N
Lithium
Battery
Only
Long
Delay
Time
[
71
Sec
-
1
—
'
At
6
ln
Long
Delay
Setting
HI
'
n
Long
Delay
Setting
m
'
n
Long
Delay
Time
[
71
Sec
.
-
1
—
1
At
6
ln
2
2
0
0
0
0
Short
Delay
Pickup
sCDln
Short
Delay
Pickup
Breaker
Trips
In
6
T
Test
Amps
0
Breaker
Trips
In
6
T
Test
Amps
0
'
n
Gnd
.
Fault
Pickup
0
'
n
V
E
ln
Gnd
Fault
Pickup
0
'
n
S
0
IN
\
0
0
Short
Delay
Time
[
~
2
~
|
Sec
Short
Delay
Time
[
7
|
Sec
0
o
*
o
Pt
*
=
Pt
Test
Test
\
0
0
\
Gnd
.
Fault
Time
[
T
|
Sec
.
Gnd
.
Fault
Time
|
11
Sec
.
o
Inst
o
Trip
Trip
PH
Reset
Reset
0
0
0
Unit
<
2
>
Unit
<
2
>
Status
Status
Inst
.
Gnd
Gnd
.
Override
/
Discrimmator
NP
256
P
656
H
4
I
NP
256
P
656
H
31
Fig
.
2.6
Long
Time
/
Short
Timellnstantaneous
Ground
Protection
(
LSIG
)
Nameplate
Fig
.
2.5
Long
Time
/
Short
TimelGround
Protection
(
LSG
)
Nameplate
Courtesy of NationalSwitchgear.com

4
The
back
-
up
battery
is
provided
to
maintain
the
mode
of
trip
LED
indicators
following
an
automatic
trip
operation
and
simultaneous
loss
of
control
power
to
the
Power
/
Relay
mod
-
ule
.
It
does
not
provide
control
power
for
the
microprocessor
.
In
the
Digitrip
RMS
600
Trip
Unit
all
required
sensing
and
tripping
power
to
operate
its
protection
function
is
derived
from
the
current
sensors
in
the
circuit
breaker
.
The
secondary
current
signals
from
these
sensors
provide
the
correct
mag
-
nitude
of
current
for
protection
functions
as
well
as
tripping
power
during
normal
circuit
breaker
operating
periods
.
Using
these
current
signals
in
the
protection
function
,
analog
volt
-
ages
are
developed
across
various
calibrating
resistors
including
:
1.3
Testing
Integral
test
provisions
with
selectable
"
Trip
"
and
"
No
Trip
"
test
positions
are
provided
.
For
phase
testing
,
five
"
No
Trip
"
test
settings
and
one
"
Trip
"
test
setting
are
provided
.
For
ground
fault
testing
,
one
"
No
Trip
"
and
one
"
Trip
"
setting
are
pro
-
vided
.
Test
and
Trip
Reset
pushbuttons
are
provided
.
2.0
UL
Listed
Devices
1
)
Phase
current
2
)
Ground
fault
current
(
when
supplied
)
3
)
Rating
plug
The
resulting
analog
voltages
are
multiplexed
into
an
analog
-
to
-
digital
converter
and
the
output
data
fed
into
the
microcom
-
puter
chip
along
the
data
bus
.
Digitrip
RMS
600
Trip
Units
are
listed
by
the
Underwriters
Laboratories
,
Inc
.
for
use
in
types
SPB
,
DS
and
DSL
and
Series
C
R
-
Frame
circuit
breakers
under
U
.
L
.
File
E
7819
.
The
microcomputer
,
in
cyclic
fashion
,
repeatedly
scans
the
resultant
voltage
values
across
each
calibrating
resistor
and
enters
these
values
into
its
RAM
or
Read
/
Write
Memory
.
This
data
,
which
is
used
to
calculate
true
RMS
current
values
,
is
repeatedly
compared
with
the
pre
-
set
protection
function
pick
-
up
settings
and
other
operating
data
stored
in
the
ROM
or
Read
Only
Memory
.
The
microcomputer
software
program
is
then
used
,
in
decision
tree
fashion
,
to
initiate
protection
func
-
tions
including
tripping
actions
through
the
low
energy
flux
transfer
trip
coil
in
the
circuit
breaker
.
3.2
Making
Current
Release
(
Discriminator
)
3.0
Principle
of
Operation
3.1
General
The
Digitrip
RMS
600
Trip
Unit
provides
three
basic
functions
:
Protection
,
Information
and
Testing
.
A
typical
trip
unit
and
rating
plug
are
illustrated
in
Fig
.
1
.
Individual
product
instruc
-
tion
leaflets
referenced
in
Sections
9.1
and
9.2
illustrate
typical
Digitrip
RMS
Trip
Units
installed
in
specific
breakers
.
The
trip
unit
uses
the
INTEL
MCS
-
51
family
of
microcomputers
to
perform
its
numeric
and
logic
functions
.
The
principle
of
operation
can
best
be
described
by
referring
to
the
block
dia
-
gram
shown
in
Fig
.
3
.
When
the
Digitrip
RMS
600
Trip
Unit
is
not
equipped
with
an
adjustable
instantaneous
protection
setting
,
i
.
e
.
,
types
LS
or
LSG
,
a
making
current
release
(
or
discriminator
)
circuit
is
pro
-
vided
.
This
circuit
will
prevent
the
circuit
breaker
from
being
120
Volt
50
/
60
Hertz
Control
Power
i
Y
N
A
B
C
in
ttt
)
)
>
Auxiliary
Power
Module
Input
(
When
Used
)
—
•
Short
Circuit
Alarm
—
•
High
Load
Alarm
—
9
Long
Delay
Alarm
—
•
Ground
Fault
Alarm
i
•
Alarm
Common
Power
/
Relay
Module
Trip
i
*
Relay
Signal
Contacts
/
Y
Aux
.
CT
'
s
Ol
i
and
Typical
Cause
of
Trip
LEDs
Located
on
Front
Panel
GFP
Test
|
“
“
1
/
Summing
Bridge
Circuits
Power
Supply
CT
£
»
STY
Rating
Plug
\
/
\
/
\
<
—
«
YY
r
i
I
Typical
Phase
or
Ground
Calibration
Resistor
V
Fig
.
3
Digitrip
RMS
600
Block
Diagram
with
Breaker
Interface
Courtesy of NationalSwitchgear.com

5
closed
and
latched
-
in
on
a
faulted
circuit
.
The
non
-
adjustable
release
is
pre
-
set
at
eleven
(
11
)
times
the
installed
rating
plug
ampere
rating
(
ln
)
.
the
circuit
breaker
and
referenced
in
Sections
9.1
and
9.2
.
Sim
-
ilarly
,
if
the
zone
interlocking
function
is
chosen
not
to
be
used
,
defeater
connections
on
each
circuit
must
be
added
as
illus
-
trated
in
the
same
referenced
diagrams
.
The
making
current
release
is
armed
only
for
the
first
ten
(
10
)
cycles
following
an
initial
circuit
breaker
closing
operation
pro
-
vided
the
load
current
exceeds
approximately
10
%
of
the
circuit
breaker
frame
or
sensor
rating
.
Should
the
load
current
through
the
circuit
breaker
drop
to
a
value
less
than
this
,
the
release
will
re
-
arm
.
The
release
,
once
armed
,
will
remain
armed
until
approximately
10
%
load
current
passes
through
the
breaker
for
10
cycles
.
Any
trip
operation
initiated
by
the
making
current
release
will
trip
the
circuit
breaker
instantaneously
.
3.5
Trip
and
Operation
Indicators
Red
colored
LEDs
,
as
shown
in
Figs
.
1
and
2
,
also
indicate
on
the
face
of
the
trip
unit
the
mode
of
trip
of
any
automatic
trip
operation
.
As
indicated
in
Fig
.
2
,
each
LED
is
strategically
located
in
the
related
segment
of
the
Time
-
Current
curve
depicted
on
the
face
of
the
trip
unit
.
The
mode
of
trip
is
identified
by
the
segment
of
the
Time
-
Current
curve
in
which
the
LED
is
turned
"
On
"
.
3.3
Instantaneous
Override
External
control
power
is
required
to
operate
the
Power
/
Relay
module
.
The
power
/
relay
module
maintains
the
mode
of
trip
LED
indicators
in
their
"
On
"
position
following
an
automatic
trip
operation
as
long
as
the
control
power
is
available
.
With
a
loss
of
control
power
following
an
automatic
trip
operation
,
a
back
-
up
battery
as
illustrated
in
Figs
.
3
and
5
is
provided
to
perform
this
function
.
In
addition
,
when
the
Digitrip
RMS
600
Trip
Unit
is
not
equipped
with
an
adjustable
instantaneous
setting
,
i
.
e
.
,
types
LS
or
LSG
,
a
high
-
set
non
-
adjustable
instantaneous
override
trip
circuit
is
provided
.
This
high
level
tripping
action
is
preset
to
a
specific
value
that
reflects
the
short
time
withstand
rating
of
the
circuit
breaker
in
which
the
trip
unit
is
installed
.
Specific
values
vary
between
circuit
breaker
types
and
ratings
.
For
specific
infor
-
mation
,
refer
to
the
supplementary
leaflets
and
/
or
Time
-
Cur
-
rent
curves
referenced
in
Sections
9.1
and
9.2
.
A
green
colored
battery
check
,
LED
and
test
pushbutton
,
as
shown
in
Figs
.
1
and
5
,
are
provided
to
check
the
status
of
the
battery
.
3.4
Zone
Interlocking
A
green
colored
LED
,
as
shown
in
Fig
.
1
,
indicates
the
oper
-
ational
status
of
the
trip
unit
.
With
external
control
power
avail
-
able
at
the
Power
/
Relay
module
(
or
via
the
external
Auxiliary
Power
module
during
bench
testing
operations
)
,
the
green
LED
will
flash
"
On
"
and
"
Off
"
once
each
second
.
A
flashing
green
LED
is
an
indication
of
a
properly
operating
trip
unit
.
As
indicated
in
the
block
diagram
in
Fig
.
3
,
zone
interlock
sig
-
nals
are
provided
.
For
Digitrip
RMS
600
Trip
Units
equipped
with
either
ground
fault
or
short
time
protection
functions
or
both
,
separate
zone
interlocking
circuits
are
provided
.
When
utilized
,
these
input
/
output
signals
must
be
connected
in
the
ultimate
equipment
assembly
in
line
with
details
provided
with
the
specific
circuit
breaker
connection
diagrams
supplied
with
T
Unit
Status
Indicator
Front
Panel
Numerical
Displays
and
Pointer
LED
'
s
/
Integral
Input
Pushbuttons
and
Switches
*
4
Test
Panel
i
i
’
'
i
A
Multiplexer
V
(
MUX
)
Central
Processor
Unit
(
CPU
)
I
Multiplexer
(
MUX
)
Data
Bus
A
>
I
Zone
Interlock
Circuitry
Flux
Transfer
Shunt
Trip
or
Direct
Trip
Actuator
I
f
IN
Analog
Override
FET
*
Trip
OUT
Circuit
Courtesy of NationalSwitchgear.com

6
A
red
colored
LED
,
as
shown
in
Fig
.
1
,
indicates that the
load
current
through
the circuit breaker has reached
85
%
of
the
preset
value
of
the
Long Delay
Setting
.
The
High
-
Load
LED will
turn
"
On
"
and the
High
-
Load
relay
,
located
internally
in
the
Power
/
Relay
module shown
in
Fig
.
4
,
will
pick
-
up
after
an
approximate
40
second
delay
.
This
delay
allows the alarm
to
ride
-
through
a
momentary
high
-
load condition thus
avoiding
nuisance alarms
.
played
in
the window
will
remain
in
view
until
a
change
is
implemented
.
A
step
pushbutton
is
provided
to
step
among
the available
currents
.
3.6
.
1.2
After
Trip
or
Trouble
For the
after
trip
and trouble
conditions
,
one
of
the
following
coded
messages
will
appear
in
the
display
window
:
3.6
Readout
Display
Message
Condition
Action
/
Comment
The
four
-
digit
alpha
-
numeric
readout
display
window
,
illus
-
trated
in
Figs
.
1
and
2
,
serves
two
basic
purposes
:
instrumen
-
tation and
mode
of
trip
or
trouble
indication
.
LDPU
Overload
in
Progress
Indication is
warning signal
.
Trip
will
occur
if
condition
persists
.
Instrumentation
LDT
Overload
Trip
Trip
action
initiated
as
result
of
an
overload
.
During
normal service conditions
,
with
the
circuit
breaker
closed
,
it
serves an
ammeter
instrumentation
function
.
It
displays
the
individual
phase
currents
(
l
/ \
,
lg
,
l
^
)
and
ground
current
(
IQ
)
provided
integral
ground
fault
protection
is included
in
the
trip
unit
.
Current
values
are
displayed
in
kA
.
The actual
current
value
being displayed
is
indicated
by
the marked
LED
that
is
turned
"
On
"
.
A
stepping
pushbutton
is
provided
to
step
among
the
different
currents
.
Clear
overload
,
reset
trip
unit and reclose breaker
as
required
.
SDT
Short
Trip
action initiated
as
result
of
fault
exceeding
trip
setting
.
Examine breaker
to
insure
reclosing
action is
appropriate
.
Reset
trip
unit
and reclose breaker
only
after
reason
for
trip
has
been
corrected
.
/
Delay
Trip
Mode
of
Trip
and Trouble Indication
Following
an
automatic circuit breaker
trip
operation
and
with
control
power
available
to
the Power
/
Relay
module
,
the Read
-
out
Display
indicates the mode
of
trip
using
coded
messages
such
as
,
INST
(
Instantaneous
Trip
)
,
SDT
(
Short
Delay
Trip
)
,
LTD
(
Long Delay
Trip
)
and
GNDT
(
Ground
Fault
Trip
)
.
The coded
message
will
lock
-
in
position
until
the
Stepping
Pushbutton is
depressed
.
Afterwards
,
the
Display
will
indicate the
value
of
current
(
in
kA
)
at
the time
of
the
trip
initiation
by
the
protection
function
involved
.
Trip
action initiated
as
result
of fault
exceeding
trip
setting
.
Examine breaker
to
insure
reclosing
action is
appropriate
.
Reset
trip
unit
and
reclose
breaker
only
after
reason
for
trip
has
been
corrected
.
INST
©
Instantaneous
Trip
The Power
/
Relay
module
requires
a
120
V
.
,
50
/
60
Hz
,
6
VA
.
control
power
supply
for
operating
the Readout
Display
and
internally
mounted
signal relays
.
Following
an
automatic
trip
operation
of
the circuit breaker
,
it
will
maintain
the
cause
of
the
trip
history
and
the
mode
of
trip
LEDs
as
long
as
the
exter
-
nal control
power
supply
is
available
.
Each
signal
relay
contact
is
rated
120
V
.
,
50
/
60
Hz
,
1.0
A
.
Trip
action
initiated
as
result
of
ground
fault
exceeding
trip
setting
.
Examine
breaker
to
insure
reclosing
action
is
appropriate
.
Reset
trip
unit and reclose
breaker
only
after
reason
for
trip
has
been
corrected
.
GNDT Ground
Fault
Trip
3.6
.
1
Readout
Display
Messages
The
Readout
Display
provides
ammeter
instrumentation under
normal service
conditions
of
the circuit breaker
and
alpha
-
numeric
coded
messages
after
an
automatic
trip
.
To
properly
understand the
actions
of
the
trip
unit
,
each
coded
message
must
be
understood
as
well
as
any
required
follow
-
up
oper
-
ational
action
.
Messages
can
be
divided
into
two
categories
:
Normal service
and
after
trip
or
trouble
conditions
.
Trip
action
initiated
by
Discriminator
-
most
likely
on
initial
breaker
closing
action
.
Examine
breaker
to
insure
that
rectosing
action
is
appropriate
.
Reset
trip
unit and
reclose
breaker
only
after
reason
for
trip
has
been
cleared
.
DISC
©
Making
Current
Release
(
Discriminator
)
Trip
3.6
.
1.1
Normal
Service
Normal service
messages
are
those
that
serve
the
ammeter
instrumentation
function
.
In
Fig
.
1
,
four
green
colored
LEDs
serve
a
pointer
function
,
i
.
e
.
,
phase
A
current
(
l
/
\
)
,
phase
B
current
(
lg
)
,
phase
C
current
(
IQ
)
and
ground
current
(
IQ
)
.
The
ground
current
LED will
be included
only
if
integral ground
fault
protection
is
included
as an
integral
part
of
the
trip
unit
protections
functions
.
Trip
action
initiated
by
override
circuit
indicative
of
a
high
level
fault
.
Examine
breaker
to
insure
that
reclosing
action
is
appropriate
.
Reset
trip
unit
and
reclose breaker
only
after
reason
for
trip
has
been
cleared
.
ORID
©
©
Override
Trip
Each
LED
,
when
turned
"
On
"
,
will
indicate
the
current
being
displayed
in
the
four
-
digit display
window
.
The
current
dis
-
Courtesy of NationalSwitchgear.com

7
Message
Condition
Action
/
Comment
3.6
.
1.3
.
1
Case
1
-
Overload
Trip
Operation
TEST
Test
in
Progress
This
message
will
appear
when
the
integral
test
pushbutton
is
depressed
and
will
disappear
when
the
test
pushbutton
is
released
{
indicating
test
has
started
)
.
The
test
message
only
appears
when
a
complete
breaker
trip
test
is
selected
,
i
.
e
.
,
6
T
or
GFT
(
see
Fig
.
7
)
Assume
a
prolonged
overload
condition
which
results
in
an
automatic
breaker
trip
operation
.
The
following
will
occur
:
1
.
The
Long
Delay
Trip
LED
will
turn
"
On
"
(
see
Fig
.
1
)
2
.
The
coded
message
LDT
will
appear
in
the
Display
Window
(
see
Fig
.
1
)
3
.
The
Long
Delay
Relay
in
the
Power
/
Relay
Module
(
see
Figs
.
3
and
4
)
will
operate
to
transmit
a
remote
Long
Delay
alarm
signal
.
PLUG
Rating
Plug
Problem
This
message
will
appear
should
there
be
a
missing
,
improperly
installed
or
defective
rating
plug
.
Operator
Actions
Observe
the
mode
of
trip
LED
and
coded
alpha
-
numeric
message
in
the
Display
Window
.
1
.
RAM
Data
Memory
Problem
This
message
will
appear
in
response
to
a
data
memory
test
failure
.
Depress
trip
unit
Trip
Reset
to
reconfirm
message
.
If
message
reappears
,
replace
trip
unit
.
Depress
Stepping
Pushbutton
twice
(
see
Fig
.
1
)
.
This
action
will
clear
the
coded
cause
of
trip
message
in
the
Display
Window
.
2
.
View
value
of
phase
current
in
Display
Window
(
see
Fig
.
1
)
e
.
g
.
,
1.50
(
in
kA
)
.
3
.
ROM
Program
Memory
Problem
This
message
will
appear
in
response
to
a
program
memory
test
failure
.
Depress
trip
unit
Trip
Reset
to
reconfirm
message
.
If
message
reappears
,
replace
trip
unit
.
Note
:
The
phase
current
shown
will
be
that
refer
-
enced
by
the
Pointer
LED
(
see
Fig
.
1
)
that
is
turned
"
On
,
"
assume
"
IA
-
(
It
may
not
be
the
faulted
phase
)
.
Depress
the
Stepping
Pushbutton
to
move
from
LED
"
IA
to
LED
"
lg
"
to
LED
"
lc
"
-
At
each
position
,
the
related
value
of
phase
current
(
in
kA
)
at
the
time
of
the
trip
operation
will
appear
in
the
Display
Window
.
4
.
Notes
:
©
All
values
of
current
displayed
were
present
prior
to
initi
-
ation
of
the
trip
signal
.
In
the
case
of
a
high
-
level
fault
condition
where
fast
tripping
is
desirable
,
the
trip
unit
will
operate
before
a
complete
RMS
current
value
can
be
cal
-
culated
.
For
this
reason
,
the
displayed
value
may
be
less
than
the
actual
RMS
fault
current
.
Reset
the
trip
unit
by
depressing
the
"
Trip
Reset
"
push
-
button
(
see
Fig
.
1
)
.
All
coded
messages
and
current
values
in
the
display
window
,
the
cause
of
trip
LED
and
the
signal
relay
in
the
Power
/
Relay
module
will
turn
"
Off
"
.
5
.
Notice
©
In
the
case
of
very
high
fault
levels
outside
the
range
of
normal
current
sensor
accuracy
ranges
,
the
message
"
ORNG
"
(
indicating
over
range
)
will
appear
at
each
phase
readout
position
when
the
trip
message
"
ORID
"
(
indicating
override
)
is
interrogated
by
the
stepping
pushbutton
.
On
trip
operations
initiated
by
the
long
delay
trip
(
LDT
)
function
it
is
essential
that
any
cause
of
over
-
load
trip
be
corrected
prior
to
reclosing
the
circuit
breaker
.
Should
it
not
be
corrected
and
the
circuit
breaker
be
reclosed
too
soon
,
then
because
of
the
inherent
Long
Time
Memory
Function
,
the
Long
Delay
trip
time
will
operate
faster
than
the
related
time
-
current
curve
indicates
.
(
D
The
override
value
in
the
trip
unit
is
set
to
operate
at
approx
-
imately
100
X
the
frame
/
sensor
ampere
rating
For
circuit
breakers
having
lower
withstand
ratings
,
other
details
are
provided
in
the
breaker
to
insure
proper
applications
within
the
breaker
withstand
rating
.
The
amount
of
time
required
to
clear
the
memory
circuit
is
a
factor
of
the
Long
Delay
time
setting
(
see
Fig
.
6.2
)
.
The
longer
the
delay
setting
,
the
longer
the
time
required
to
reset
the
memory
.
Total
memory
clearing
time
could
vary
from
one
to
twelve
(
12
)
minutes
depending
upon
the
time
delay
setting
selected
.
3.6
.
1.3
Analyzing
"
After
Trip
"
Coded
Messages
As
indicated
in
Section
3.6
,
as
long
as
control
power
is
avail
-
able
to
the
Power
/
Relay
Module
,
coded
messages
will
lock
-
in
position
on
the
Readout
Display
until
the
stepping
pushbutton
is
depressed
.
Likewise
,
the
individual
values
of
phase
and
ground
current
,
if
any
,
at
the
time
the
automatic
trip
was
initiated
will
also
lock
-
in
position
and
remain
until
the
trip
unit
is
reset
by
depressing
the
reset
pushbutton
.
The
manner
that
these
coded
messages
operate
can
best
be
understood
by
referring
to
the
following
examples
:
The
memory
function
,
as
in
any
conventional
thermal
type
(
bi
-
metal
)
circuit
breaker
,
serves
a
useful
function
by
allowing
the
load
conductors
to
cool
down
.
6
.
After
correcting
the
cause
of
the
overload
trip
(
LDT
)
and
allowing
for
the
memory
circuit
to
reset
,
reclose
the
circuit
breaker
as
required
following
established
operating
procedures
.
Given
A
1600
amp
circuit
breaker
with
a
1000
amp
rating
plug
installed
.
Courtesy of NationalSwitchgear.com

8
View
value
of
phase
current
in
Display
Window
(
see
Fig
.
1
)
e
.
g
.
,
12.0
(
in
kA
)
.
Note
:
The
phase
current
shown
will
be
that
refer
-
enced
by
the
Pointer
LED
(
see
Fig
.
1
)
that
is
turned
"
On
"
(
It
may
not
be
the
faulted
phase
)
,
assume
"
IA
"
-
Note
:
During
the
overload
condition
,
prior
to
the
automatic
trip
operation
,
the
following
trip
unit
indi
-
cations
would
have
been
visible
:
3
.
1
.
The
"
High
-
Load
"
LED
(
Fig
.
1
)
would
have
been
turned
"
On
"
if
the
overload
condition
had
existed
for
40
seconds
or
longer
.
Depress
the
Stepping
Pushbutton
to
move
from
LED
"
IA
"
to
LED
"
IB
"
to
LED
"
IQ
"
.
At
each
position
,
the
related
value
of
phase
current
(
in
kA
)
at
the
time
of
the
trip
operation
will
appear
in
the
Display
Window
.
2
.
The
"
High
-
Load
"
relay
in
the
Power
/
Relay
Module
(
see
Figs
.
3
and
4
)
would
have
picked
-
up
(
after
a
40
second
delay
,
)
to
close
a
contact
for
a
remote
High
-
Load
alarm
.
4
.
3
.
The
Long
Delay
LED
(
Fig
.
1
)
would
have
been
flashing
"
On
"
and
"
Off
"
.
Note
:
Should
the
level
of
fault
current
be
very
high
,
then
,
the
coded
message
ORID
could
appear
in
the
Display
Window
.
When
the
step
pushbutton
is
depressed
,
the
coded
message
ORNG
rather
than
a
numerical
current
value
would
appear
.
This
would
be
indicative
of
a
very
high
fault
level
outside
the
range
of
normal
current
sensor
accuracy
ranges
.
4
.
The
coded
message
LDPU
would
have
been
flashing
in
the
Display
Window
.
3.6
.
1.3
.
2
Case
2
-
Instantaneous
Trip
Operation
Assume
a
high
-
level
fault
above
the
instantaneous
trip
setting
-
Assume
8
x
ln
-
(
see
Fig
.
1
)
.
Following
the
trip
operation
,
the
following
will
occur
:
Reset
the
trip
unit
by
depressing
the
"
Trip
Reset
"
push
-
button
(
see
Fig
.
1
)
.
All
coded
messages
and
/
or
current
val
-
ues
in
the
display
window
,
the
cause
of
trip
LED
and
the
signal
relay
in
the
Power
/
Relay
module
will
turn
"
Off
"
.
5
.
1
.
The
Instantaneous
Trip
LED
will
turn
"
On
"
(
see
Fig
.
1
)
.
2
.
The
coded
message
INST
will
appear
in
the
Display
Window
(
see
Fig
.
1
)
.
Following
any
corrective
actions
in
the
system
and
inspec
-
tions
of
the
circuit
breaker
and
related
equipment
,
reclose
the
circuit
breaker
as
required
.
6
.
3
.
The
Short
Circuit
Relay
in
the
Power
/
Relay
Module
(
see
Figs
.
3
and
4
)
will
operate
to
close
a
contact
for
a
remote
Short
Circuit
Alarm
.
3.6
.
1.3
.
3
Other
Cases
Similar
type
indications
will
occur
and
similar
operator
actions
will
be
required
as
described
in
the
above
two
cases
following
an
automatic
trip
operation
initiated
by
any
other
of
the
Pro
-
tection
Functions
,
including
Short
delay
and
ground
fault
.
Operator
Actions
1
.
Observe
the
mode
of
trip
LED
and
coded
message
in
the
Display
Window
.
3.7
Test
Provisions
2
.
Depress
Stepping
Pushbutton
(
see
Fig
.
1
)
.
This
action
will
clear
the
coded
cause
of
trip
message
in
the
Display
Window
.
An
integral
test
panel
including
a
test
selector
switch
and
test
and
reset
pushbuttons
is
provided
to
test
the
circuit
breaker
in
either
a
TRIP
or
NO
-
TRIP
test
mode
under
qualified
condi
-
tions
.
See
Section
5
.
For
bench
testing
of
the
trip
unit
alone
or
of
the
trip
unit
while
it
is
installed
in
the
circuit
breaker
,
an
optional
Auxiliary
Power
module
(
Catalog
No
.
PRTAAPM
)
as
shown
in
Fig
.
7
is
available
.
This
Auxiliary
Power
module
,
which
operates
from
a
separate
120
Vac
,
supply
,
may
also
be
used
when
a
drawout
type
circuit
breaker
is
in
any
of
its
four
cell
positions
,
i
.
e
.
,
"
Connected
”
,
"
Test
"
,
"
Disconnected
"
and
"
Withdrawn
"
(
or
"
Removed
"
)
.
4.0
Protection
Settings
4.1
General
Prior
to
placing
any
circuit
breaker
in
operation
,
all
available
protection
settings
should
be
set
using
values
as
recom
-
mended
by
the
specifying
engineer
responsible
for
the
instal
-
lation
.
The
number
of
settings
that
must
be
made
will
be
a
factor
of
the
protection
model
supplied
as
illustrated
in
Figs
.
2.1
through
2.6
.
Each
setting
is
made
with
an
eight
position
rotary
switch
using
a
small
screwdriver
.
The
selected
setting
for
each
adjustment
will
appear
in
the
small
rectangular
open
-
ing
as
illustrated
in
Fig
.
1
.
The
installed
rating
plug
establishes
the
maximum
continuous
current
rating
of
the
circuit
breaker
.
All
current
pick
-
up
settings
in
the
protection
module
are
defined
in
per
unit
multiples
of
the
ampere
rating
(
ln
)
of
the
installed
rating
plug
.
Fig
.
4
PowerIRelay
Module
.
Courtesy of NationalSwitchgear.com

9
To illustrate the
portion
of
the
protection
curve
being
adjusted
,
simulated
Time
-
Current
curves are
pictured
on
the
face of
the
trip
unit
.
The
particular
setting
to
be
adjusted
is located
in
close
proximity
to
its
portion
of
the simulated Time
-
Current
curve
.
Should
an
automatic
trip
occur as
a
result
of
a
fault
current
exceeding
the
preselected
value
in
this
portion
of
the Time
-
Current
curve
,
the
red
LED
shown
in
this
segment
of
the
sim
-
ulated
Time
-
Current
curve
will
turn
"
On
”
.
times the
ampere
rating
(
ln
)
of
the
installed
rating plug
up
to
a
maximum
pick
-
up
value
of
1200
A
.
Specific
current
pick
-
up
values
are
tabulated
in
Table
1
and
on
the
ground
fault
Time
-
Current
curve
of
the
applicable
circuit
breaker
.
Under
primary injection
test
conditions conducted
with
the breaker outside
of
its
cell and the external
Auxiliary
Power
module shown
in
Fig
.
8
is used
,
the tabulated
values should
be
in
effect
.
The available
settings
,
along
with
the
illustrated
effect of
changing
the
settings
,
are
given
in
Figs
.
6.1
through
6.7
.
The tabulated values shown
in
Table
1
are
based
on
the
use
of
a
residual
current
sensing
scheme
with
the
same
rated
cur
-
rent
sensor
for
all
phase
and neutral conductors
.
Refer
to
the
applicable
supplemental
circuit
breaker
instruction
leaflet
shown
in
Sections
9.1
and
9.2
for
values
applicable
to
alternate
sens
-
ing
schemes
.
4.2
Long
Delay
Settings
Eight
(
8
)
available
settings
,
as
indicated
in
Fig
.
6.1
,
range
from
0.5
to
1.0
(
ln
)
.
Each
setting
is
expressed
as a
multiple
of
the
maximum
ampere
rating
(
ln
)
of
the
installed
rating
plug
.
Table
1
-
Ground
Fault
Current
Pickup
Settings
4.3
Long
Delay
Time
Settings
PICKUP
SETTINGS
GROUND
FAULT
CURRENTS
(
AMPERES
)
©
Eight
(
8
)
available
settings
,
as
illustrated
in
Fig
.
6.2
,
range
from
2
to
24
seconds
.
These
settings
represent
total
clearing
times
at
a
current
value
equal
to
six
(
6
)
times
the
installed
rating
plug
ampere
rating
(
ln
)
.
E
?
F H
K
A
®
B
@
C
®
D
®
50 60
75
100
100
25
30 35
40
120 150
200
200 50 60 70
80
100
4.4
Short
Delay
Pick
-
up
Settings
©
88 100 125 150
188 250
250
63
75
c
120
150
180 225
300
300
75
90
105
As illustrated
in
Fig
.
6.3
,
eight
(
8
)
available
settings
range
from
2
to
6
(
ln
)
with
two
variable
settings
of
S
1
and
S
2
.
These
var
-
iable
settings
depend
upon
the
type
of
circuit breaker
in
which
the
trip
unit is installed
.
Specific
information
on
these
settings
is
given
in
the
supplemental
instruction
leaflet
referenced
in
Sections
9.1
and
9.2
that is
supplied
with
the circuit
breaker
.
Specific
information
is
also
shown
on
the
rating plug
and
on
the
applicable
Time
-
Current
curve
.
(
/
)
Hi
200
240
300
400
400 100
120
140 160
DC
LD
Q
-
210 240
300 360
450 600
600 150
180
5
<
320
600
800
200
240
280
400 480
800
O
300
350
400
500 600 750
1000
1000 250
600 720 900
1200
Q
-
360
420
480
1200
300
©
1200
1200
640 800 960
1600
400
480 560
Z
h
-
1000
1200 1200 1200
600
700 800
2000
500
<
4.5
Short
Delay
Time
Settings
cc
960 1200
1200 1200 1200
600 720
840
2400
O
Hi
1200
1200 1200 1200
750 875
1000
2500
625
As
illustrated
in
Fig
.
6.4
,
two
different
curve
configurations
are
possible
,
i
.
e
.
,
flat
or
l
2
t
response
.
The
configuration
selected
will
be
a
factor of
the
type
of
selective
coordination
being
developed
.
The
l
2
t
response
will
provide
a
longer
time
delay
in
the
low
-
end
of
the short
delay
pick
-
up
range
than
will
the
flat
response
setting
.
Five
flat
(
0.1
,
0.2
,
0.3
,
0.4
,
0.5
sec
.
)
and three
l
2
t
(
0.1
,
0.3
,
0.5
sec
.
)
response
time
delay
settings
are
provided
.
The
l
2
t
response
settings
are
identified
by
the
suffix
asterisk
(
*
)
that
appears
in
the
setting viewing
window
.
The
l
2
t
response
is
applicable
only
up
to
eight
(
8
)
times the
ampere
rating
of
the installed
rating
plug
(
ln
)
.
After
this value
is
exceeded
,
the
l
2
t
response
config
-
uration
reverts to
a
flat
response
.
4.6
Instantaneous
Pick
-
up
Settings
As
illustrated
in
Fig
.
6.5
,
eight
(
8
)
available
settings
range
from
2
to
6
(
ln
)
with
two
variable
settings
M
1
and
M
2
.
These
variable
settings
depend
upon
the
type
of
circuit breaker
in
which the
trip
unit is
installed
.
Specific
information
on
these
settings
is
given
in
the
supplemental
instruction
leaflet
referenced
in
Sec
-
tions
9.1
and
9.2
that is
supplied
with
the
circuit breaker
.
Spe
-
cific information
is also shown
on
the
rating plug
and
on
the
applicable
Time
-
Current
curve
.
4.7
Ground
Fault
Current
Pick
-
up
Settings
<
1200 1200 1200
900
1050 1200
1200
3000
750
H
(
/
)
1200 1200 1200
1200
1200
800 960
1120
3200
Z
1200
1200
1200
1200
1200 1200
1200
4000
1000
1200
1200
1200 1200
1200
1200 1200 1200
5000
©
Tolerances
on
pickup
levels
are
±
10
%
of
values shown
in
chart
.
©
Ground
fault
pickup
levels shown
are
nominal
values when
tested
with
external
control
power
present
.
This could be
with
the
Power
/
Relay
Module
energized
or
with
the
auxiliary
power
module
energized
.
Without
external
control
power
,
the
pick
-
up
level
may
be
as
high
as
the value
shown
for
the
"
E
"
setting
of
that
particular
plug
.
<
D
Refer
to
Type
DS
,
Type
SPB
or
Type
Series C
R
-
Frame
supplemental
instruction
leaflets
given
in
Section
9
for
list
of
available
rating
plugs
with
each
type
circuit
breaker
.
4.8
Ground
Fault
Time
Delay
Settings
As
illustrated
in
Fig
.
6.7
,
two
different
curve
configurations
are
possible
,
i
.
e
.
,
flat
or
l
2
t
response
.
The
configuration
selected
will
be
a
factor of
the
type
of
selective coordination
being
developed
.
The
l
2
t
response
will
provide
a
longer
time
delay
in
the
low
-
end
of
the
ground
fault
pick
-
up
range
than
will
the
flat
response
setting
.
Five
flat
(
0.1
,
0.2
,
0.3
,
0.4
,
0.5
,
sec
)
and
three
l
2
t
(
0.1
,
0.3
,
0.5
sec
)
response
time
delay settings
are
provided
.
The
l
2
t
response
settings
are
identified
by
the
suffix
asterisk
(
*
)
that
appears
in
the
setting
viewing
window
.
The
l
2
t
response
is
applicable
only
up
to
0.625
times the
ampere
rating
of
the
installed
rating plug
(
ln
)
.
Beyond
this value
,
the
l
2
t
response
configuration
reverts
to
a
flat
response
.
As
illustrated
in
Fig
.
6.6
,
eight
(
8
)
available
settings
are
given
in
alphabetical
notations
from
A
to
K
(
there is
no
"
G
"
notation
)
.
Specific
setting
values
are a
function of
the installed
rating
plug
.
In
general
,
the
pick
-
up
settings
range
from
0.25
to
1.0
Courtesy of NationalSwitchgear.com

10
Fig
.
5
Typical
Rating
Plug
5.0
Integral
Test
Panel
-
Test
Procedure
5.1
General
Since
the
Digitrip
RMS
600
Trip
Unit
requires
external
control
power
to
operate
the
Power
/
Relay
Module
,
any
in
-
service
test
-
ing
elected
to
be
done
may
be
conducted
without
the
insertion
of
the
Auxiliary
Power
Module
.
As
illustrated
in
Figs
.
1
and
7
,
an
integral
test
panel
is
provided
to
test
the
Digitrip
RMS
600
Trip
Unit
.
Adequate
no
-
trip
settings
are
provided
to
insure
that
the
trip
unit
is
operational
without
tripping
the
circuit
breaker
.
5.2
When
to
Test
Tests
can
be
conducted
with
the
breaker
in
the
"
connected
"
cell
position
while
carrying
load
current
.
However
,
as
stated
in
the
caution
note
in
Section
5.1
,
good
practice
will
limit
circuit
breaker
in
-
service
"
trip
tests
"
,
where
required
,
to
maintenance
periods
during
times
of
minimum
load
conditions
.
Testing
,
prior
to
start
-
up
can
best
be
accomplished
with
the
breaker
out
of
its
cell
or
in
the
"
Test
"
,
"
Disconnect
"
or
"
Withdrawn
"
(
or
"
Removed
"
)
cell
positions
.
CAUTION
THE
TRIPPING
OF
A
CIRCUIT
BREAKER
UNDER
"
TEST
CONDITIONS
"
WHILE
IT
IS
IN
SERVICE
AND
CAR
-
RYING
LOAD
CURRENT
,
WHETHER
DONE
BY
INTE
-
GRAL
OR
EXTERNAL
TEST
MEANS
,
IS
NOT
RECOMMENDED
.
Note
:
Since
time
-
current
settings
are
based
on
desired
system
coordination
and
protection
schemes
,
the
protection
settings
selected
and
preset
under
Section
4.0
above
should
not
be
altered
during
or
as
a
part
of
any
routine
test
sequence
.
ANY
SUCH
TRIPPING
OPERATION
WILL
CAUSE
DIS
-
RUPTION
OF
SERVICE
AND
POSSIBLE
PERSONAL
INJURY
RESULTING
FROM
UNNECESSARY
SWITCHING
OF
CONNECTED
EQUIPMENT
.
5.3
Test
Provision
Testing
of
a
circuit
breaker
that
results
in
the
tripping
of
the
circuit
breaker
should
be
done
only
with
the
circuit
breaker
in
the
"
Test
"
or
"
Disconnected
"
cell
positions
or
while
the
circuit
breaker
is
on
a
test
bench
.
As
indicated
in
Fig
.
7
,
six
different
test
settings
(
1
,
2
,
3
,
6
T
,
8
and
10
x
ln
)
are
available
for
testing
the
phase
elements
of
the
trip
unit
and
two
(
GF
,
GFT
)
are
provided
for
testing
the
ground
elements
.
One
setting
under
each
test
mode
(
6
T
and
GFT
)
will
initiate
a
tripping
action
of
the
circuit
breaker
.
To
preserve
the
primary
protection
function
of
the
trip
unit
,
all
in
-
service
testing
under
"
Trip
"
or
"
No
-
Trip
"
conditions
must
be
done
at
load
current
values
no
greater
than
40
%
of
the
plug
rating
(
ln
)
.
Any
attempt
to
conduct
in
-
service
testing
above
this
value
will
be
Automatically
aborted
by
the
trip
unit
.
*
No
abort
signal
will
occur
for
tests
conducted
unless
the
cir
-
cuit
breaker
is
carrying
load
current
.
Courtesy of NationalSwitchgear.com