Date Code 20080103 Instruction Manual SEL-351S Relay
Section 3
Overcurrent, Voltage, Synchronism Check,
Frequency, and Power Elements
Instantaneous/Definite-Time Overcurrent Elements
Phase Instantaneous/
Definite-Time
Overcurrent Elements
Four levels of phase instantaneous/definite-time overcurrent elements are
available. Two additional levels of phase instantaneous overcurrent elements
(Levels 5 and 6) are also available. The different levels are enabled with the
E50P enable setting, as shown in Figure 3.1, Figure 3.2, and Figure 3.3.
Level 2 element 67P2S in Figure 3.3 is used in directional comparison
blocking schemes (see Directional Comparison Blocking (DCB) Logic on
page 5.27). All the other phase instantaneous/definite-time overcurrent
elements are available for use in any tripping or control scheme.
Settings Ranges
Setting range for pickup settings 50P1P–50P6P:
0.25–100.00 A secondary (5 A nominal phase current inputs, IA, IB, IC)
0.05–20.00 A secondary (1 A nominal phase current inputs, IA, IB, IC)
Setting range for definite-time settings 67P1D–67P4D:
0.00–16000.00 cycles, in 0.25-cycle steps
Setting range for definite-time setting 67P2SD (used in the DCB logic):
0.00–60.00 cycles, in 0.25-cycle steps
Accuracy
Pickup: ±0.05 A secondary and ±3% of setting
(5 A nominal phase current inputs, IA, IB, IC)
±0.01 A secondary and ±3% of setting
(1 A nominal phase current inputs, IA, IB, IC)
Timer: ±0.25 cycles and ±0.1% of setting
Transient Overreach: ±5% of setting
To Next Page
Loading...
