GE MicroVersaTrip Plus - Page 25

SECTION
6
TESTING
AND
TROUBLESHOOTING
WARNING
:
Do
not
change
taps
on
the
current
sensors
or
adjust
the
programmer
trip
unit
set
-
tings
while
the
breaker
is
carrying
current
.
Once
the
breaker
has
been
converted
,
but
before
it
is
energized
,
it
must
be
tested
.
See
below
for
troubleshooting
details
.
TESTING
Before
installing
a
converted
breaker
back
into
service
,
perform
the
following
steps
:
Step
1
.
Verify
that
the
programmable
trip
unit
is
securely
installed
.
The
phase
sensors
must
not
be
ener
-
gized
if
they
are
open
-
circuited
.
Step
2
.
Megger
the
breaker
primary
circuit
using
a
1
,
000
-
Volt
Megger
.
Step
3
.
Measure
the
resistance
across
the
line
and
load
terminals
for
each
phase
using
a
Micro
-
Ohmeter
or
Milli
-
Volt
tester
.
Also
,
measure
the
resistance
across
the
CT
assembly
.
If
the
resistance
differs
considerably
from
phase
to
phase
,
the
electrical
points
may
not
be
properly
tightened
.
Also
,
it
may
indicate
improper
contact
wipe
.
Step
4
.
To
verify
that
the
breaker
has
been
properly
ret
-
rofitted
,
a
primary
injection
test
should
be
per
-
formed
on
each
phase
.
This
test
will
check
the
CTs
,
bus
,
wiring
harness
,
flux
shifter
,
and
trip
unit
as
a
complete
system
.
A
high
current
,
low
voltage
power
supply
should
be
connected
across
each
line
and
load
terminal
to
simulate
an
overcurrent
fault
.
The
long
-
time
may
be
set
at
0.5
to
minimize
the
breaker
stress
.
When
ground
fault
is
installed
,
the
test
can
be
performed
by
wir
-
ing
two
adjacent
poles
in
series
.
This
will
prevent
the
breaker
from
tripping
due
to
an
unbalance
current
flow
.
Do
not
attempt
to
use
GE
test
kit
Cat
.
No
.
TVTS
1
or
TVRMS
on
this
programmer
.
Troubleshooting
When
malfunctioning
is
suspected
,
first
examine
the
circuit
breaker
and
its
power
system
for
ab
-
normal
conditions
such
as
:
1
.
Breaker
not
tripping
in
proper
response
to
overcurrents
or
incipient
ground
faults
.
2
.
Breaker
remaining
in
a
trip
-
free
state
due
to
mechanical
interference
along
its
trip
shaft
.
3
.
Inadvertent
shunt
trip
activations
.
False
Tripping
Breakers
Equipped
with
Ground
Fault
When
nuisance
tripping
occurs
on
breakers
equipped
with
the
ground
fault
trip
element
,
a
probable
cause
is
the
existence
of
a
false
“
ground
”
signal
.
Each
phase
sensor
is
connected
to
summing
circuitry
in
the
programmer
.
Under
no
-
fault
conditions
on
3
-
wire
load
circuits
,
the
currents
add
to
zero
,
and
no
ground
signal
is
de
-
veloped
.
This
current
sum
will
be
zero
only
if
all
three
sensors
have
the
same
electrical
characteris
-
tics
.
If
one
sensor
differs
from
the
others
(
i
.
e
.
,
dif
-
ferent
rating
or
wrong
tap
setting
)
,
the
circuitry
can
produce
output
sufficient
to
trip
the
breaker
.
Similarly
,
discontinuity
between
any
sensor
and
the
trip
unit
can
cause
a
false
trip
signal
.
The
sensors
and
their
connections
should
be
closely
examined
if
nuisance
tripping
is
encoun
-
tered
on
any
breaker
whose
MicroVersaTrip
-
Plus
or
PM
components
have
previously
demonstrated
satisfactory
performance
.
After
disconnecting
the
breaker
from
all
power
sources
,
perform
the
following
steps
:
Step
1
.
Check
that
all
phase
sensors
are
the
same
type
(
ampere
range
)
.
Step
2
.
Make
sure
that
the
tap
settings
on
all
three
-
phase
sensors
are
identical
.
Step
3
.
Verify
that
the
harness
connections
to
the
sensors
meet
the
polarity
constraints
indicated
by
the
ca
-
bling
diagram
in
Fig
.
50
.
25
Courtesy of NationalSwitchgear.com