Schweitzer Engineering Laboratories SEL-351A - Figure 3.30 Undervoltage Block for Frequency Elements (Group Setting VNOM ≠ OFF); Frequency Elements

3.49
Date Code 20080213 Instruction Manual SEL-351A Relay
Overcurrent, Voltage, Synchronism Check, and Frequency Elements
Frequency Elements
Frequency Elements
Three or six frequency elements are available, depending on SEL-351A
model. Enable the desired number of frequency elements with the E81 enable
setting:
E81 = N (none), 1 through 6 (SEL-351A)
E81 = N (none), 1 through 3 (SEL-351A-1)
as shown in Figure 3.32. Frequency is determined from the voltage connected
to voltage terminals VA-N.
Frequency Element
Settings
q Figure 3.32.
Figure 3.30 Undervoltage Block for Frequency Elements (Group Setting
VNOM ≠ OFF)
q Figure 3.32.
Figure 3.31 Undervoltage Block for Frequency Elements (Group Setting
VNOM = OFF)
0
5
CYC
27B81P
Setting
VA/VAB
VB/VBC
VC/VCA
Voltages
Wye/Delta
to Frequency Element
Logic (
q
)
27B81
Relay
Word
Bit
0
5
CYC
27B81P
Setting
VA/VAB
Voltages
Wye/Delta
to Frequency Element
Logic (q)
27B81
Relay
Word
Bit
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