Siemens Static Trip III - Metering and Extended Protective Relaying; Metering Functions Overview

Metering
and Extended
Protective
Relaying
I
ib/
Metering Functions
The
metered
and logged
parameters
of Static Trip lllC/CP/CPX
trip units may
be monitored
remotely
over
the communications
bus
or locally
with the Breaker
Display
Unit
(see
Breaker
Display
Unit
section). The
specifications
of the metered
para-
meters
are
given
in
the following
table.
The real{ime
and
min/max
values
represent
averages of
each measured
para-
meter
over approximately
one second.
Measured
Parameters
Specif
ications
Parameter
Description
Phase
Currents Measured
RMS
Value
of each
Phase
Current
Range:
0
to
1000%
of Phase
Current
Accuracy:
:"i;::?'xi3!'"H'i$,.,,",
I
0% to 125%
of Phase
Sensor
BDU Display:
la
=
XXXX
lb
=
XXXX
lc
=
XXXX
Average
Phase
Arithmetic
Average
of Phase
A, Phase
B,
Current
and Phase
C Currents
BDU Display:
l*
=
YXXX
Ground
Current Measured
RMS
Value
of Ground
Current
Range
0 lo 125%
of Ground
Sensor
Primary
Rating
Accuracy:
+17"
of Ground
Sensor from
10%
to
125%
of
Ground Sen-
BDU
Disptay: ij't=
*ru
Neutral
Current
Measured
RMS Value
of Neutral
Current
Range:
0 to 1000%
of Neutral
Current
Sensor Primary
Rating
Accuracy:
+1"/"
of Neutral
Sensor from
10%lo
125%
of Neutral
Sensor
BDU Display:
ln
=
XXXX
Phase Voltages
Measured
RMS Value
of each
Phase
Voltage
(4
Wire
Mode
only)
Range
0 to 380 Volts
Accuracy:
!1%
of
reading
from 70
to
380 Volts
BDU
Display: Va
=
XXX
Vb
=
XXX
VC
=
XXX
Arithmetic
Average
of A, B
and C
Phase
Voltages
(4-Wire
mode
only)
BDU
Display:
V*.= XXX
Measured
RMS Value
of
each Line to
Line
Voltage
(3-Wire
and 4-Wire
Modes)
Range:
0
to 660 Volts
Accuracy:
!1%
of
reading
from
I20 to
660 Volts
BDU Display:
Vab
=
XXX
VbC
=
XXX
VCa
=
XXX
Arithmetic
Average
of A-B B-C,
and C-A
Line
to Line Voltage
BDU Display:
VXX
=
XXX
Description
Measured Line Frequency
taken from
Phase
A Voltage
Range:
45.0 to 70.O Nz
Accuracy:
!.25%
of
reading
provided
Va
is above 90V,
BDU
Display: Hz
=
XX.X
Signed
Sum of the Measured Real Power
of all 3 Phases in
Kilowatts
Range: x7,200
(Normally
Limited
by
Breaker
Size)
Accuracy:
+2%
of
Reading
provided
power
factor
is
greater
than
50% and current and voltage
signals are within their speci-
fied accuracy ranges.
BDU Display:
kW
=
XXXX
Signed
Sum of the Measured Power
of all
3
Phases
in Kilovars
Range: 17,200
(Normally
Limited by
Breaker
Size)
Accuracy:
t2% of Reading
provided
power
factor is less
than
90% and current and voltage
signals are within their speci-
fied accuracy ranges.
BDU Display:
kQ
=
XXXX
Sum of the Apparent
Power of all 3
Phases
in Kilovolt Amperes
Range:
O Io 7
,2O0
(Normally
Limited
by Breaker
Size)
Accuracy:
t2%
of
Reading
provided,
current and voltage signals
are within
their specified ac-
curacy ranges.
BDU Display: kVA
=
XXXX
Ratio
of Real Power
to
Apparent
Power
Range:
-.99
to
.1.00
Accuracy: .04
between .50 leading and
.50 lagging
provided
current
and voltage
signals are
within their specified
accu-
racy ranges.
BDU
Display: PF
=
X.XX
Signed Accumulation of Real Energy in
1000's
of
Watt
Hours
Range:
0tot9999,999KilowattHours
Accuracy:
+2%ofReading
BDU Display:
kWh
=
XXXX
(or
MWh
=
XXXX)
Accumulation
of Real Energy in 1000's
of
Negative
Watt Hours
Range:
0 to t9,999,999 Kilowatt
Hours
Accuracy:
x2%
of Reading
BDU
Display:
-kwh
XXXX
(or
-MWh
XXXX)
Signed Accumulation
of
Reactive
Energy
in I000's
of
VAR
Hours
Range:
0tot9,999,999KiloVARHours
Accuracy:
+27"
of
Reading
BDU Display:
kQh
=
XXXX
(or
MQh
=
XXXX)
Parameter
Frequency
Real Power
Reactive Power
Apparent
Power
Power Factor
Kilowatt
Hours
Kilowatt
Hours
Reverse
Average
Phase
Voltage
Line Voltages
Average
Line Voltage
r-U
KiloVAR
Hours
21