GE b30 User Manual

GE Multilin B30 Bus Differential System 6-13
6 ACTUAL VALUES 6.3 METERING
6
DELTA-CONNECTED INSTRUMENT TRANSFORMERS:
The zero-sequence voltage is not measurable under the Delta connection of instrument transformers and is defaulted to
zero. The table below shows an example of symmetrical components calculations for the ABC phase rotation.
* The power system voltages are phase-referenced – for simplicity – to VAG and VAB, respectively. This, however, is a
relative matter. It is important to remember that the B30 displays are always referenced as specified under
SETTINGS
 SYSTEM SETUP  POWER SYSTEM  FREQUENCY AND PHASE REFERENCE.
The example above is illustrated in the following figure.
Figure 6–2: MEASUREMENT CONVENTION FOR SYMMETRICAL COMPONENTS
• ABC phase rotation: • ACB phase rotation:
Table 6–1: SYMMETRICAL COMPONENTS CALCULATION EXAMPLE
SYSTEM VOLTAGES, SEC. V * VT
CONN.
RELAY INPUTS, SEC. V SYMM. COMP, SEC. V
V
AG
V
BG
V
CG
V
AB
V
BC
V
CA
F5AC F6AC F7AC V
0
V
1
V
2
13.9
∠0°
76.2
∠–125°
79.7
∠–250°
84.9
∠–313°
138.3
∠–97°
85.4
∠–241°
WYE 13.9
∠0°
76.2
∠–125°
79.7
∠–250°
19.5
∠–192°
56.5
∠–7°
23.3
∠–187°
UNKNOWN (only
V
1
and
V
2
can be determined)
84.9
∠0°
138.3
∠–144°
85.4
∠–288°
DELTA 84.9
∠0°
138.3
∠–144°
85.4
∠–288°
N/A 56.5
∠–54°
23.3
∠–234°
V_0 N/A=
V_1
130– °∠
33
--------------------
V
AB
aV
BC
a
2
V
CA
++()=
V_2
130°∠
33
-----------------
V
AB
a
2
V
BC
aV
CA
++()=
V_0 N/A=
V_1
130°∠
33
-----------------
V
AB
a
2
V
BC
aV
CA
++()=
V_2
130– °∠
33
--------------------
V
AB
aV
BC
a
2
V
CA
++()=
827844A1.CDR
A
B
C
WYEVTs
1
0
2
A
B
C
DELTA VTs
1
2
SYSTEM VOLTAGES SYMMETRICAL
COMPONENTS
UR phase angle reference
UR phase angle reference
UR phase angle
reference
UR phase angle
reference

GE b30 Specifications

General

Model	b30
Manufacturer	GE
Coil Voltage	N/A (Solid State Relay)
Coil Power	N/A (Solid State Relay)
Mechanical Life	N/A (Solid State Relay)
Electrical Life	N/A (Solid State Relay)