ISA-351G Feeder Protection, Measurement, and Control Device Module

Protection Functions

1) Phase current over-limit recording element with independent threshold

2) Three-stage current protection that can be independently enabled or disabled

3) Inverse-time overcurrent protection with selectable extreme, very, or general operating characteristics

4) Phase current acceleration protection with selectable pre-acceleration or post-acceleration

5) Selectable three-phase single/double auto-reclosing (with optional synchronization check and dead-line detection)

6) Under-frequency load shedding with slip/no-slip blocking

7) Under-voltage load shedding with voltage slip blocking

8) Zero-sequence overcurrent protection with directional element, compatible with different grounding methods

9) Overload protection

10) Control circuit break alarm with optional reclosing blocking function

11) Bus PT break alarm with optional blocking of voltage-related protections

12) External input protection with settable delay and enable/disable option

13) Independent operation circuit and fault recording

14) Remote ground fault line selection test trip function for ungrounded systems (automatic identification of line grounding)

15) Blocking of simplified busbar protection

Measurement and Control Functions:

1) 3 position remote signals collected via the operation circuit; 8 (expandable to 20) remote input signals, with options for reclosing blocking, external trip input, external alarm input, external reset, and device maintenance; multiple soft remote signals including general fault signal, reclosing ready flag, and protection soft壓板

2) 21 telemetry quantities: Ia, Ib, Ic, Ua, Ub, Uc, 3I0, Uab, Ubc, Uca, 3U0, Pa, Pb, P, Q, S, φ, Fr, 3I01, 3I05

3) Operation switch and soft壓板 control, with operation switch recording and statistics

4) Large-capacity event recording, SOE recording, self-check recording, and instantaneous protection blocking recording

5) Harmonic analysis function up to the 11th order

6) Bay-specific five防 interlocking function with rules consistent with the five防 host