PROT_46_NPS
ANSI 46 negative-sequence overcurrent on the machine's own I2 squared t withstand, with a decaying thermal replica and time-to-trip.
When to use it
Use PROT_46_NPS when a synchronous machine must be protected against sustained current unbalance — an open phase, a broken conductor, an unbalanced fault, or a large single-phase load — where the damage mechanism is double-frequency eddy-current heating of the rotor surface.
Interface
The published port signature. This is the whole of what the block exposes to your program — the implementation body is not shown here and ships with the download.
Inputs
| Port | Type | Unit |
|---|---|---|
| ENABLE | BOOL | — |
| I2 | REAL | A |
| I2_OK | BOOL | — |
| I_NOM | REAL | A |
| I2_PCT | REAL | % |
| K_I2T | REAL | s |
| COOL_S | REAL | s |
| RESET_PCT | REAL | % |
| DO_RATIO | REAL | pu |
| BLK | BOOL | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| PICKUP | BOOL | — |
| TRIP | BOOL | — |
| INHIBIT | BOOL | — |
| I2_MEAS_PCT | REAL | % |
| I2T_PCT | REAL | % |
| T_TRIP | TIME | — |
| T_TRIP_VALID | BOOL | — |
| BLOCKED | BOOL | — |
| ALM_MEAS_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Supervised control write
PROT_46_NPS commands a real actuator. It is written to sit underneath your own interlock, permissive and protection logic — not to replace it. Commission it as you would any control block you wrote yourself.
Validation evidence
- Tests
- 11
- Simulated scans
- 344
- Simulator
- v0.1.0
Complete IEC 61131-3 implementation with a published test suite that runs on the vplant simulator. The counts above are that suite, executed on this build.
- Conforms to IEC 61131-3
- Conforms to IEC 61499
Download PROT_46_NPS — free
Create a free Ri Tech account to download the block. You get the Structured Text body, the Rockwell Add-On Instruction (.L5X), the Schneider Control Expert DFB (.XDB), PLCopen XML, the IEC 61499 function block type (.fbt) and the datasheet.
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Source is never published on this page. The implementation is released to a signed-in Ri Tech account — free of charge, but never anonymously.