GE MDP

GEK
-
100682
©
NOMENCLATURE
1
MDP
0
000
A
No
communications
or
control
inputs
(
Block
Ground
,
Block
Instantaneous
,
Breaker
Status
)
Control
inputs
and
communications
upgrade
socket
CommNet
MOD
BUS
RTU
RS
232
RS
485
0
I
2
3
4
5
5
Amp
Nominal
,
0.5
to
4.375
Amps
Ground
5
Amp
Nominal
,
1.5
to
13.125
Amps
Ground
5
Amp
Nominal
,
0.1
to
0.875
Amp
Ground
1
Amp
Nominal
,
0.1
to
0.875
Amp
Ground
1
Amp
Nominal
,
0.3
to
2.625
Amp
Ground
1
Amp
Nominal
,
0.05
to
0.4375
Amp
Ground
5
Amp
Nominal
,
0.5
to
4.375
Amp
Ground
/
Phase
1
2
3
4
5
«
;
6
7
1
24
-
48
VDC
(
19
to
60
VDC
)
48
-
125
VDC
/
AC
(
38.5
to
150
VDC
/
AC
)
35
to
120
AC
110
-
250
VDC
(
88
to
285
VDC
)
85
to
240
AC
D
Revision
Level
2
3
APPLICATION
Time
-
overcurrent
relays
are
used
for
the
protection
of
feeders
,
transmission
lines
,
alternating
-
current
machines
and
transformers
,
and
for
numerous
other
applications
where
accurate
measurement
of
current
and
timing
is
necessary
.
The
operating
tune
of
associated
protective
devices
should
be
considered
in
the
selection
of
a
time
-
current
characteristic
for
a
particular
application
,
to
ensure
proper
coordination
with
a
minimum
of
circuit
isolation
.
Four
basic
time
-
current
characteristics
are
available
in
Type
-
MDP
relays
.
short
-
circuit
current
flowing
through
any
given
relay
is
more
dependent
upon
the
location
of
the
fault
relative
to
the
relay
than
on
the
system
generation
setup
at
the
time
of
the
fault
.
The
extremely
inverse
-
time
-
current
characteristic
shown
in
Figure
4
is
preferred
for
applications
where
sufficient
time
delay
must
be
provided
to
allow
a
re
-
energized
circuit
to
pick
up
an
accumulated
cold
load
without
unnecessary
tripping
on
inrush
currents
.
Distribution
-
feeder
circuits
are
a
good
example
of
such
applications
,
and
the
extremely
-
inverse
characteristic
is
best
suited
to
such
applications
because
it
more
nearly
approximates
typical
power
-
fuse
and
fuse
-
cutout
characteristics
.
m
The
inverse
-
time
-
current
characteristic
curves
are
shown
in
Figures
1
,
2
and
5
.
Figure
5
depicts
the
BS
142
inverse
curve
and
applies
to
the
1
Amp
model
relays
only
.
These
relays
are
generally
applied
where
the
short
-
circuit
-
current
magnitude
is
dependent
largely
upon
the
system
generating
capacity
at
the
time
of
the
fault
.
The
very
inverse
-
time
-
current
characteristic
shown
in
Figure
3
is
generally
applied
where
the
magnitude
of
The
general
practice
for
grounded
-
distribution
-
system
protection
is
to
use
three
phase
-
overcurrent
functions
for
protection
against
interphase
faults
and
a
ground
/
residual
overcurrent
function
for
single
-
phase
-
to
-
ground
faults
.
5
Courtesy of NationalSwitchgear.com