PROT_40_LOE
ANSI 40 loss of excitation by sustained reactive import, with optional voltage supervision and an arming delay after breaker close.
When to use it
Use PROT_40_LOE when a synchronous machine needs loss-of-field protection and the available measurements are real and reactive power rather than terminal impedance — the normal case on a packaged set, a small hydro unit or any machine whose relay is a power meter.
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 | — |
| KVAR | REAL | kvar |
| KVAR_RATED | REAL | kvar |
| Q_OK | BOOL | — |
| IMPORT_PCT | REAL | % |
| DELAY | TIME | — |
| HYST_PCT | REAL | % |
| V_SUPERVISE | BOOL | — |
| V_PCT | REAL | % |
| V_OK | BOOL | — |
| V_LOW_PCT | REAL | % |
| CB_CLOSED | BOOL | — |
| ARM_DLY | TIME | — |
| BLK | BOOL | — |
| ACK | BOOL | — |
Outputs
| Port | Type | Unit |
|---|---|---|
| PICKUP | BOOL | — |
| TRIP | BOOL | — |
| ARMED | BOOL | — |
| Q_PCT | REAL | % |
| V_LOW | BOOL | — |
| BLOCKED | BOOL | — |
| ALM_MEAS_FAULT | BOOL | — |
| ALM_VT_FAULT | BOOL | — |
| ALM_CFG_ERR | BOOL | — |
IEC 61499 event interface
EI INIT, REQ·EO INITO, CNF
Supervised control write
PROT_40_LOE 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
- 274
- 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_40_LOE — 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.