A unit standing at a non-zero share and producing nothing is seen by NOTHING.
SAFETY-30's per-unit sign gate needs OPPOSITION on both sides of 250 W and a
unit at 0 W is not opposing, it is ABSENT. The site sum still agrees with the
meter in direction. Circulating power is exactly zero when one unit does
nothing. The only trace left is `reason == "saturated-freeze"`, which
clamp.py:93-96 documents as the alarm an operator learns to ignore. It is
HW-01's shape, which ran 6 h 25 m with all three layers spectators.
⚠️ THE CARD'S OWN DISCRIMINATOR WAS BUILT FIRST AND FALSIFIED, AND THAT IS THE
MAIN CONTENT. SAFETY-42 asks for "saturation persisting past N while
|grid error| > X, both derived". Run on the two-master rig it fails in BOTH
directions, and no (N, X) fixes either:
FALSE POSITIVE `plantsim.Plant.limit()` returns 0 W for a discharge command
into a pack at its own floor, and a wedged unit produces 0 W too. Load
2000 W, equal weights, 2000 W per-unit cap, 120 cycles: THE TWO ARMS ARE
IDENTICAL ON ALL 120 in grid, site target, every share and every measured
watt. Both saturated-freeze on 116 of them, both hold |grid error| over
300 W on all 120 and settle at 1200 W, both read circulating 0.0 W. The
predicate's inputs do not differ, so no threshold on them can differ. And
"a cold pack at its floor must not alarm" is the card's own AC 2.
FALSE NEGATIVE the standing grid error is what a HEALTHY SIBLING ERASES.
Load 800 W, same config, B wedged: over the last 30 of 200 cycles the loop
is frozen on 30 of 30 while the worst |grid error| is 30 W, with B standing
at +770 W and delivering 0 W. Any X above 30 W is silent for the whole run
on the exact fault the card describes.
WHAT REPLACES IT. Per unit, for a discharge share, `share - measured`; readable
because of a reduction that only exists at N>=2:
a unit is named while it is short by more than `saturation_w` with NO
ACCOUNT for it, and the units in that state are a PROPER SUBSET of the units
asked to discharge.
THE ACCOUNT keeps the cold pack out and is the only thing that can: the two
cases are identical in the power domain, so the discriminator has to be a
non-power fact, and there is exactly one - the pack's own SoC against its own
`bms_soc_floor`, asked through `peakguard.discharge_permitted()` rather than
transcribed. ⚠️ `bms_soc_floor` ALONE, not `pack_floor_pct()`'s conjunction with
`peak_soc_floor`: that floor bounds a money-saving discharge only and using it
would explain away a wedged unit anywhere between the two.
THE PROPER SUBSET keeps a whole-site cause out - a derate this add-on cannot see
hits every unit; one box that stopped listening does not - and it is what makes
this INERT AT N=1, by algebra rather than by a roster guard.
IT REPORTS. IT DOES NOT ACT, and the strongest argument is for acting. Dropping
the wedged unit from `live` genuinely recovers a site the shipped path does not:
at load 1500 W, kept in the split the site settles at 800 W with a 700 W error
and NEVER comes inside 100 W in 150 cycles (the freeze pins the target, so the
sibling's SHARE never grows); dropped, it delivers 1500 W from cycle 14. What
refuses it is that the only re-allocation this add-on can express is
all-or-nothing: a unit derated to 50 % is short by more than saturation_w with
nothing to explain it, so this detector names it too, and at load 3000 W
dropping it leaves the site delivering 2000 W against 2400 W kept - 400 W WORSE.
A partial re-allocation is what would make acting safe and the allocator cannot
express it. That is a card.
control.py is NOT MODIFIED. The freeze shapes the loop; this reports on it.
NUMBERS, MEASURED. The watts side is `Tuning.saturation_w`, read at runtime, so
there is no fourth CFG-03 copy and it cannot drift from the number the control
law itself calls "not following". `delivery_hold_s: 185` comes off 2640
closed-loop two-inverter runs in which nothing is faulty (6 gains x 5 slews over
the whole schema range, across load reversals, a flapping load and ASYMMETRIC
SPLITS - a family SAFETY-30's campaign did not have and the one that dominates
here) plus 1890 runs at a roster of ONE as the control:
threshold reversals flapping weighted N=1 control
* 500 W 20.0 s 0.0 s 30.0 s 0.0 s
The N=1 column is 0.0 s at EVERY threshold in all 1890 runs, and the flapping
column - the family that defeated SAFETY-30's site window - is zero too, because
a common stimulus makes both units short at once and the subset stops being
proper. ⚠️ The curve is NOT monotone (55.0 s at 250 W against 40.0 s at 100 W):
lowering the threshold can turn a proper subset into the whole roster and BREAK
the run.
⚠️ THE MARGIN IS MEASURED, NOT FELT, BECAUSE INVERTER B DOES NOT PHYSICALLY
EXIST. `plantsim.INVERTER_B` is A COPIED, `measured=False`, so every two-inverter
figure above is two copies of A. Sweeping a different second unit: the worst
legitimate episode is insensitive to B's RAMP (30.0 s at half A's) and scales
with its LAG - 45.0 s at twice A's measured 10 s, 90.0 s at four times it.
185 s is 6.2x the measured worst, 2.06x the four-times-slower case, 6.2x
LINK_STALE_S and 4.9x inside the 900 s quarter. Deliberately not 180, which is
SAFETY-02's site hold.
SAFETY-34. `unit/<name>/delivery_tripped` in the store, one notification id per
unit, re-raised on the first cycle of every process, cleared by the Start press.
No flat mirror: a rollback lands on a version that drives one actuator, where
this check is inert.
⚠️ SCHEMA CHANGE - `delivery_hold_s` joins options: and schema:, so this needs a
version bump before it ships. Additive and defaulted, so an existing options blob
stays valid.
STATED GAPS: charge shares are not graded (no configured charge ceiling exists,
so a constant-voltage taper cannot be explained and arming it would fire on every
maintenance charge); every unit wedged at once is not caught (the subset is not
proper and no instrument here separates that from a plant that cannot).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwRLw7eKYj2byVdwB6kbjU
