Sel 411L - Table 3.67 EPO Setting Selections; Table 3.68 Pole Open Logic Relay Word Bits

P.3.135
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
Pole Open Logic
NOTE: The 3PO, SPOA, SPOB, SPOC,
and SPO Relay Word bits shown in
Figure 3.80 are used in some
protective elements of the relay.
Separate Relay Word bits SPOBKn,
3POBKn, 2POBKn (n = 1 or 2), and
3POLINE are not affected by the EPO
setting and are used in the
autoreclose logic only—see Figure 4.5
and Figure 4.6.
Set EPO to V only if you use line-side potential transformers for relaying
purposes. Do not select option V if shunt reactors are applied because the
voltage decays slowly after the circuit breaker(s) opens. If you select
EPO := V, the relay cannot declare an open pole when LOP is asserted.
Table 3.67 EPO Setting Selections
Selection Description
52 Phase undercurrent and circuit breaker auxiliary contact input status
V Phase undercurrent and phase undervoltage
Table 3.68 Pole Open Logic Relay Word Bits
Name Description
SPOA A-phase open
SPOB B-phase open
SPOC C-phase open
SPO One or two poles open
3PO All three poles open
27APO A-phase undervoltage
—pole open
27BPO B-phase undervoltage
—pole open
27CPO C-phase undervoltage
—pole open