Controls — ST interlocks memo
| Field | Detail |
|---|---|
| Primary artifact(s) | controls/water/st/interlocks.st |
| Spec | RO-SPEC-001 §5.6 ; WIRE-001 §8 |
Summary
Documents hard interlock Boolean factors for ladder merge — not standalone coil drivers. Sequence tasks (RO, fill SM, ice demand) AND these permissives onto DO_VFD10x_RUN_AUX, metering-pump enables, and UV contactor paths.
| Interlock | Input / condition | Action |
|---|---|---|
| BV-101 | DO_BV101_BALL_VALVE energised (Y1) | Spring-return NC actuator — de-energise fails closed; open required before pump run permissives |
| T-101 LSH | DI_LSH101_T101_HIGH | Inhibit P-101 / VFD-101 run |
| T-101 LSL | DI_LSL101_T101_LOW | Stop P-102 / VFD-102; latch ALM_T101_LEVEL_LOW_LATCH |
| HOA selectors | Placeholder DI_HOA_*_AUTO (GCX3370) | MP-101/102/103 and UV branch permissive booleans merged before DO coils |
Exported merge tags: intlk_p101_run_ok, intlk_p102_run_ok, intlk_hoa_mp101_ok … intlk_hoa_uv_ok.
Ladder translation
The .st file ends with an ASCII rung comment block (ILK-001 … ILK-010) marked CRITICAL HARD INTERLOCK COPY. Field ladder must mirror those rungs; sequence logic must not bypass the series stacks.
Test
controls/water/sim-tests/sim-t101-lsl-stop-p102.md— LSL drops VFD-102 run auxcontrols/water/sim-tests/sim-ro-start-stop.md— BV + LSH gate VFD-101
Cold bench jumper tests per BENCH-001 Phase A.
Open items
- Land GCX3370 selector contacts on spare DI; replace HOA placeholder defaults with
DI_HOA_MP101_AUTO,DI_HOA_MP102_AUTO,DI_HOA_MP103_AUTO,DI_HOA_UV_AUTOintags.csv