| Field | Detail |
|---|
| Primary artifact(s) | controls/water/st/ice-demand.st |
| Spec | RO-SPEC-001 §5.6 ; WIRE-001 §9 (SV manifold polarity) |
Summary
FS-101 ice-machine demand opens SV-ICE when guards pass; SV-RECIRC closes (or energises per plumbing convention) whenever ice or treat paths redirect flow.
| Input | Role |
|---|
DI_FS101_ICE_DEMAND | Ice machine demand switch FS-101 |
DI_LSL101_T101_LOW | T-101 low float — feeds internal ICE_OK_LEVEL heuristic |
| Guard | Effect when active |
|---|
SEQ_DISINFECT_LOCKOUT_ACTIVE | Block DO_SV_ICE; recirc stays default-open |
ALM_UV_LAMP_FLT | Block DO_SV_ICE (UV hard fault latch) |
NOT ICE_OK_LEVEL | Block ice draw on low T-101 |
| Output | Behaviour |
|---|
DO_SV_ICE | TRUE when FS-101 demand and all guards pass (N.C. coil — energised opens path) |
DO_SV_RECIRC | Redirect merge: ice_cmd OR DO_SV_TREAT, mapped through CFG_SV_RECIRC_ENERGIZED_CLOSES_RECIRC_PATH |
ALM_BLOCK_ICE_ON_UV_FLT | Info latch while disinfect lockout or UV hard fault active |
uv-lockout.st may force DO_SV_ICE FALSE after this task on the same scan; recirc uses guarded ice_cmd so lockout cannot leave recirc closed with no demand path.
Test
controls/water/sim-tests/sim-ice-blocked-by-uv.md
Open items
- Confirm
CFG_SV_RECIRC_ENERGIZED_CLOSES_RECIRC_PATH default at panel build (WIRE-001 §9 option 1 vs 2)