Table of Contents
Advertisement
Metering and Extended Protective Relaying
l5r
the RS-485
communications
bus. This
requires
that the
master
network
device (such as
the
Power
MonitorrM
display
and
monitoring
unit)
first put
relay
output control
in manual mode
before open
or
close
commands
can be
issued.
While
in
manual mode, alarm functions are blocked from
automatically
opening or closing
relay
contacts; although
alarm activation
and deactivation
events
will still
be
recorded
in
the
trip
unit's
event
log.
Note that
manual operation
of the
relay
output
contacts
using
commands
issued over the RS-485 bus will be
recorded as
"relay
comm open" or
"relay
comm close"
mes-
sages
in
the
event
log.
Operation
of
alarm functions
is
not directly
affected by
the
circuit
breaker position.
lf
an
alarm
function is set
on
and
becomes active
or
inactive,
associated
messages
will
be
recorded
in
the event
log
even with
the circuit
breaker open.
Likewise,
if
relay output control has been set
to on,
relay
contacts
will open or close
regardless
of
circuit
breaker
position. This operating characteristic must be
kept
in
mind
when using the
relay
output contacts for control logic,
inter-
locking,
annunciation or
other applications and
when setting
alarm
limits.
Relay
output control cannot
be
set
to yes
unless
the
alarm
mode
is
seton.
This
effectively provides
three possible
operating
modes
for each
alarm function
as
summarized in the table
below.
O
The
event log
is
read using the
RS-485
communlcations port and
contains
trme-stamped lnformation about the most recent alarm actlvation
and deac-
tivation events. When the relay output control
is
set to yes, the event log also
identifies whlch function causes the
relay
to
close and the function
which
allows the relay to open.
@
Note
that
setting
the
relay
output
for manual
control
using
the
FS-485 com-
munlcations bus
will block
control due to alarm actlvatlon
and
deactivation.
@
The
alarm log
is
read
us ng the BDU
accessory and
contalns
nformation
about
the
alarm function whlch causes the most recent
relay
output contact
c
osure.
Note:
lf
a
trip
unit
is moved
to
a
circuit
breaker
with different
size
sensors, which require the phase sensor and possibly the
ground
sensor values
to be
reentered,
check
the alarm limits
to
insure
that their settings are compatible
with
the
different
sensor values.
Over Range
Alarms
-
For
these
types
of alarms,
if
any of the
relevant measured parameters exceed
the
programmed alarm
threshold for the alarm delay time, the
alarm
function will
go
active (assuming
the
alarm
is
not set to Off).
After going active,
the alarm will
go
inactive only when
all
the
relevant measured
parameters are below the
programmed
threshold value for at
least
1
second. When negative values
are
programmed
for
the
alarm threshold,
the
measured value
will be
considered
to
exceed the threshold only
if
the measured value is
negative
and its
absolute
value exceeds
the
absolute
value
of
the
threshold
setting.
For example,
a
measured
value
of
-800
exceeds
a
programmed
value of -700.
Under
Range
Alarms
-
For
these types
of
alarms,
if
any
of
the
relevant measured parameters are
less
than the
programmed
alarm threshold for the alarm delay time, the
alarm function
will
go
active (assuming
the
alarm
is
not set to
Off)
After
going
active,
the
alarm
will
go
inactive only when all
the
relevant
measured parameters
are
greater
than the
programmed
threshold
value for at
least
I
second.
Under Range Alarms
Unbalance Alarms
-
Unbalance
is
defined
as
the
comparison
of a
measured
phase current
or
line-to-line
voltage
to
the
arithmetic average of all three measured phase currents
or
line-to-line
voltages.
The
unbalance
is
expressed
in percent.
Allthree
measured parameters, regardless
of
their
magnitude,
are used
in
determining the average. When calculating
the
unbalance, a measured parameter is used only if its
magni-
tude
is
greater than
15%
of
the phase sensor rating
for
current
or
157o
of V
SCALE
for voltage.
If
the calculated
unbalance
exceeds
the
threshold value
for the
alarm delay
time, the
alarm
function will go active (assuming the alarm is
not set
to
Off).
After
going
active, the alarm
will
go
inactive only when
the
calculated
unbalance drops
below the
programmed threshold
value for at
least
1
second,
Unbalance
Alarms
Power Factor Alarm
-
The Power Factor
alarm
is a
unique
type
of alarm
function.
lt
is
displayed
as
a
signed
value from
-0.0-1
to +1 to +0.01. Unity power
factor
is
+1.00.
Power
factors
less
than
unity are
displayed
signed to indicate leading or lagging.
Over Range
Alarms
Alarm
Function
Alarm
Threshold
Flande
Alarm
Delay
asec I
Min.
Model
Type
Fleo
Measured
Parameter
ver
Phase Current
'1
40,000 Amos
255
la
lh
Ic
:)ver (lround
Crrrrent
1-4 000 Amns
1
255
lo
Jver
Neutral Current
1
40.000
AmDS
1
255
CN
in
Over Voltaqe
60
660 Volts
1
255
CP
Vab, Vbc,
Vca
ver
KW
10-7,200
KW
1-255
CP
Jver
KVA
I
0-7.200
KVA
1-255
OP
Over Freouencv
45.4
/Q.Q
tz
1
255
-P
lz
Over Reverse
KW
10
7
200
KW
1
255
AD
Over KW Demand
10
7,200
KW
1 255
CP
KWD
Over
KVAR
]O
7,200 KVAB
1
255
CP
k(l
Operating
Mode
Settinqs
Alarm
Actions
Alarm
Relay
Stored in
Event LoqO
Control
Belav
OutDUtO
Stored in
Alarm
Loo@
off
no
2
on
no
x
3
on
yes
x
X
x
Alarm
Function
Alarm
Pickup
Range
Alarm
Delay
(Sec.)
Min.
Model
Type
Req.
Measured
Parameter
Under Voltaoe
60-660
Volts
L_2f,f,
CP
Vab, Vbc, Vca
Under
Frequency
45.0-70.0
Hz
I.ZCJ
CP
Lz
Alarm
Function
Alarm
Pickup
Range
AIarm
Delay
(Sec.)
Min.
Model
Type
Req.
Measured
Parameter
Current Unbalance
1-255
C
la.
b.
lc
Voltaoe Unbalance
1,255
CP
Vab,
Vbc,
Vca
rb/
25
Advertisement
Table of Contents
