DataFusion SQL FDD Cookbook

Open-FDD executes production fault detection as DataFusion SQL against Apache Arrow / parquet historian tables via the canonical registry sql_rules/registry.yaml (66 entries = 62 diagnostic twins + 4 SQL analytics). Operator path: React Run Rules → POST /api/fdd/run (mode=registry). Integrators may also exercise rules through the registry APIs — raw arbitrary SQL is rejected.

Pandas mirror: the Pandas cookbook documents the 62-rule PyPI oracle (open_fdd.rules). Do not treat “62” as the production registry size. See parity matrix and the generated parity report.

Updated: 2026-08-15 · PyPI open-fdd 4.4.1

Table of contents

  1. Platform concepts
  2. Fault confirmation delay (default 5 minutes)
  3. Haystack → SQL columns
  4. Test & activate workflow
  5. Sensor validation (sweep)
  6. Control-loop hunting
  7. Air handling units
  8. VAV terminals
  9. Central plant / condenser water
  10. Heat pumps
  11. Weather station
  12. Trim & respond advisory
  13. Schedule & occupancy
  14. Not yet in validated catalog
  15. Framework & parity docs

Platform concepts

Term Meaning
telemetry_pivot Wide historian table: timestamp, equipment_id, FDD input columns
fault_raw Boolean — instantaneous fault condition (required output column)
confirmation_seconds Minimum duration fault must hold before latching (API applies after SQL)

Column names come from your Haystack assignment graph, not BACnet instance numbers.

Rule template 

-- confirmation_seconds: 300
SELECT
  timestamp,
  equipment_id,
  CASE
    WHEN oa_t IS NULL THEN false
    WHEN oa_t < -60.0 OR oa_t > 130.0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

Always handle NULL — missing samples must not latch faults.

Command scaling (0–1 vs 0–100 %) 

CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END AS fan_norm

Fault confirmation delay (default 5 minutes)

Raw rules can flicker true for one poll cycle. Open-FDD debounces after SQL returns fault_raw.

Default: confirmation_seconds: 300 (5 minutes). Change per rule in the workbench or API.

curl -s -X POST http://127.0.0.1:8080/api/fdd-rules/RULE_ID/test-sql \
  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"sql":"SELECT timestamp, equipment_id, ... AS fault_raw FROM telemetry_pivot","confirmation_seconds":300}'

Haystack → SQL columns

Binding chain:

Driver point → Haystack point → FDD input → telemetry_pivot column

Validated catalog roles use Haystack-style names (outside-air-temp, discharge-air-temp, …). Map them to your pivot column names in assignments.

Test & activate workflow

  1. Paste SQL into SQL FDD Rules (or test-sql API)
  2. Confirm fault_raw boolean column
  3. Set confirmation_seconds (default 300)
  4. Integrator JWT required to activate

Sensor validation (sweep)

Sensor-sweep rules apply to every modeled sensor present on the equipment (not a single fixed point).

SV-RANGE — Sensor out of hard range

Family: sensor · Equipment: ahu, vav, chiller, boiler, weather, zone, heatpump
Equation: Any modeled sensor reads outside its physical hard range (e.g. OAT −60–130°F, SAT 30–150°F, CHWS 30–80°F).
Default confirmation: 300 s

Param Label Unit Default Range
range_scale_temperature Temp range scale x 1.0 0.5–2.0
range_scale_humidity Humidity range scale x 1.0 0.5–2.0
range_scale_pressure Pressure range scale x 1.0 0.5–2.0 
-- confirmation_seconds: 300
-- Example hard-range screen for outdoor-air temperature (extend per sensor type)
SELECT
  timestamp, equipment_id, oa_t,
  CASE
    WHEN oa_t IS NULL THEN false
    WHEN oa_t < -60.0 OR oa_t > 130.0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot

SV-FLATLINE — Sensor flatline (stuck)

Family: sensor · Equipment: ahu, vav, chiller, boiler, weather, zone, heatpump
Equation: Sensor value unchanged (Δ ≤ tolerance) across the flatline window — stuck / frozen sensor.
Default confirmation: 300 s

Param Label Unit Default Range
flatline_tol Flatline tolerance °F 0.1 0.02–1.0
flatline_hours Flatline window h 1.0 0.5–8.0

Simplified SQL variant. Full rolling / multi-sensor logic for SV-FLATLINE is validated in Pandas. Use SQL for screening; use Pandas for parity and RCx studies.

-- confirmation_seconds: 300
-- rule: SV-FLATLINE — Sensor flatline (stuck)
-- equation: Sensor value unchanged (Δ ≤ tolerance) across the flatline window — stuck / frozen sensor.

SELECT
  timestamp,
  equipment_id,
  CASE
    -- Implement SV-FLATLINE against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

SV-SPIKE — Sensor rate-of-change spike

Family: sensor · Equipment: ahu, vav, chiller, boiler, weather, zone, heatpump
Equation: Sample-to-sample jump exceeds the physical spike limit for the sensor type.
Default confirmation: 300 s

Param Label Unit Default Range
spike_scale Spike limit scale (global) x 1.0 0.25–3.0
spike_scale_temperature Temp spike scale x 1.0 0.25–3.0
spike_scale_humidity Humidity spike scale x 1.0 0.25–3.0
spike_scale_pressure Pressure spike scale x 1.0 0.25–3.0

Simplified SQL variant. Full rolling / multi-sensor logic for SV-SPIKE is validated in Pandas. Use SQL for screening; use Pandas for parity and RCx studies.

-- confirmation_seconds: 300
-- rule: SV-SPIKE — Sensor rate-of-change spike
-- equation: Sample-to-sample jump exceeds the physical spike limit for the sensor type.

SELECT
  timestamp,
  equipment_id,
  CASE
    -- Implement SV-SPIKE against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

SV-STALE — Stale data (no fresh samples)

Family: sensor · Equipment: ahu, vav, chiller, boiler, weather, zone, heatpump
Equation: All modeled sensors unchanged over the stale window — data feed likely dropped.
Default confirmation: 300 s

Param Label Unit Default Range
stale_hours Stale window h 2.0 0.5–12.0 
-- confirmation_seconds: 300
-- Stale feed: no fresh samples in window (edge confirmation / historian gap)
SELECT
  timestamp, equipment_id,
  CASE
    WHEN timestamp < (SELECT max(timestamp) FROM telemetry_pivot) - INTERVAL '2 hours' THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot

SV-RATE — Context-aware sensor rate of change

Family: sensor · Equipment: ahu, vav, chiller, boiler, weather, zone, heatpump
Equation: Implausible sustained rate-of-change for mapped sensors. Thresholds depend on quantity, location, and operating state (steady vs startup/shutdown transient). Engineering screening defaults — tune per site. Alias: SV-SLEW. Distinct from SV-SPIKE (one-sample jump), SV-RANGE, SV-FLATLINE, and PID-HUNT-1.
Default confirmation: 600 s

Param Label Unit Default Range
persistence_min Fault persistence min 10.0 5.0–60.0
transition_window_min Transition window min 20.0 5.0–60.0
max_gap_hours Max sample gap h 2.0 0.25–6.0
design_flow Design flow (flow profiles) cfm 0.0 0.0–100000.0
sensor_span Sensor span (flow/pressure) eng 0.0 0.0–100000.0

Simplified SQL variant. Full rolling / multi-sensor logic for SV-RATE is validated in Pandas. Use SQL for screening; use Pandas for parity and RCx studies.

-- confirmation_seconds: 600
-- rule: SV-RATE — Context-aware sensor rate of change
-- equation: Implausible sustained rate-of-change for mapped sensors. Thresholds depend on quantity, location, and operating state (steady vs startup/shutdown transient). Engineering screening defaults — tune per site. Alias: SV-SLEW. Distinct from SV-SPIKE (one-sample jump), SV-RANGE, SV-FLATLINE, and PID-HUNT-1.

SELECT
  timestamp,
  equipment_id,
  CASE
    -- Implement SV-RATE against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

Control-loop hunting

PID-HUNT-1 — Suspected control-output hunting

Family: control · Equipment: ahu, vav, chiller, boiler, heatpump
Equation: Rolling 1h total variation of any 0–100% control output (dampers, valves, fan speeds, heat/cool cmds) with span ≥20%, TV ≥500 %·pts, ≥2.5 equivalent cycles, ≥4 reversals — suspected loop hunting (not proof of bad PID alone).
Default confirmation: 0 s (rolling 1h window is its own persistence)

Param Label Unit Default Range
change_deadband_pct Ignore changes below % out 1.0 0.0–10.0
minimum_span_pct Minimum observed span % out 20.0 5.0–100.0
total_variation_fault_pct Total travel threshold %/h 500.0 50.0–2000.0
minimum_equivalent_cycles Min equivalent cycles cyc/h 2.5 0.5–20.0
minimum_reversals Min direction reversals count 4 1–40
minimum_coverage_pct Minimum data coverage % 80.0 25.0–100.0

Simplified SQL variant. Full rolling / multi-sensor logic for PID-HUNT-1 is validated in Pandas. Use SQL for screening; use Pandas for parity and RCx studies.

-- confirmation_seconds: 0  (rolling 1h window is its own persistence)
-- rule: PID-HUNT-1 — Suspected control-output hunting
-- equation: Rolling 1h total variation of any 0–100% control output (dampers, valves, fan speeds, heat/cool cmds) with span ≥20%, TV ≥500 %·pts, ≥2.5 equivalent cycles, ≥4 reversals — suspected loop hunting (not proof of bad PID alone).

SELECT
  timestamp,
  equipment_id,
  CASE
    -- Implement PID-HUNT-1 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

Air handling units

Includes GL36 FC1–FC15, AHU auxiliaries, economizer/ventilation, leakage, and outdoor-air screens.

FC1 — Duct static below SP at full fan (GL36 A)

Family: ahu · Equipment: ahu
Equation: DSP < DSPSP − εDSP AND VFDSPD ≥ 100% − εVFDSPD.
Default confirmation: 300 s

Param Label Unit Default Range
eps_dsp Duct-static error εDSP (GL36 default 0.1 in.w.c.) in. w.c. 0.12 0.0–0.5
eps_vfd_spd VFD speed error εVFDSPD (GL36 default 5%) frac 0.13 0.0–0.5
duct_static_err Legacy duct-static error (sets εDSP) in. w.c. 0.12 0.0–0.5
fan_hi Legacy fan-high threshold (sets εVFDSPD) frac 0.87 0.5–1.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 300
-- param: eps_dsp = 0.12 ; eps_vfd_spd = 0.13  (fan high = 1.0 − eps_vfd_spd = 0.87)
SELECT
  timestamp, equipment_id, duct_static, duct_static_sp, fan_cmd,
  CASE
    WHEN duct_static IS NULL OR duct_static_sp IS NULL OR fan_cmd IS NULL THEN false
    WHEN (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.87
     AND duct_static < duct_static_sp - 0.12 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

FC2 — MAT below OAT/RAT envelope (GL36 B)

Family: ahu · Equipment: ahu
Equation: MATavg + εMAT < min(RATavg − εRAT, OATavg − εOAT).
Default confirmation: 600 s

Param Label Unit Default Range
eps_mat MAT sensor error εMAT (GL36 default 5°F) °F 1.15 0.0–10.0
eps_rat RAT sensor error εRAT (GL36 default 2°F) °F 1.15 0.0–10.0
eps_oat OAT sensor error εOAT (GL36 default 2°F local / 5°F global) °F 1.15 0.0–10.0
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
fan_on_min Fan-on command threshold frac 0.01 0.0–0.25
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- param: mix_tol = 1.15  (envelope = 2 * mix_tol = 2.3)
SELECT
  timestamp, equipment_id, mat, oa_t, rat, fan_cmd,
  CASE
    WHEN mat IS NULL OR oa_t IS NULL OR rat IS NULL OR fan_cmd IS NULL THEN false
    WHEN (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05
     AND mat < LEAST(oa_t, rat) - 2.3 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

FC3 — MAT above OAT/RAT envelope (GL36 C)

Family: ahu · Equipment: ahu
Equation: MATavg − εMAT > max(RATavg + εRAT, OATavg + εOAT).
Default confirmation: 600 s

Param Label Unit Default Range
eps_mat MAT sensor error εMAT (GL36 default 5°F) °F 1.15 0.0–10.0
eps_rat RAT sensor error εRAT (GL36 default 2°F) °F 1.15 0.0–10.0
eps_oat OAT sensor error εOAT (GL36 default 2°F local / 5°F global) °F 1.15 0.0–10.0
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
fan_on_min Fan-on command threshold frac 0.01 0.0–0.25
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
SELECT
  timestamp, equipment_id, mat, oa_t, rat, fan_cmd,
  CASE
    WHEN mat IS NULL OR oa_t IS NULL OR rat IS NULL OR fan_cmd IS NULL THEN false
    WHEN (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05
     AND mat > GREATEST(oa_t, rat) + 2.3 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

FC4 — PID hunting (operating-state oscillation)

Family: ahu · Equipment: ahu
Equation: ΔOS > ΔOSmax during the prior 60-minute moving window.
Default confirmation: 3600 s

Param Label Unit Default Range
delta_os_max Max mode changes/hr ΔOSmax (GL36 default 7) count 5 1–30
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0

Simplified SQL variant. Full rolling / multi-sensor logic for FC4 is validated in Pandas. Use SQL for screening; use Pandas for parity and RCx studies.

-- confirmation_seconds: 3600
-- rule: FC4 — PID hunting (operating-state oscillation)
-- equation: More than 5 operating-mode entry transitions in any hour (heating/econ/mech modes).

SELECT
  timestamp,
  equipment_id,
  outside_air_damper,
  cooling_valve,
  fan_cmd,
  CASE
    -- Implement FC4 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC5 — SAT cold when heating commanded (GL36 D)

Family: ahu · Equipment: ahu
Equation: SATavg + εSAT ≤ MATavg − εMAT + ΔTSF while heating is commanded.
Default confirmation: 600 s

Param Label Unit Default Range
eps_sat SAT sensor error εSAT (GL36 default 2°F) °F 1.15 0.0–10.0
eps_mat MAT sensor error εMAT (GL36 default 5°F) °F 1.15 0.0–10.0
delta_supply_fan Supply-fan heat rise ΔTSF (GL36 default 2°F) °F 0.55 0.0–5.0
htg_on_min Heating-command ON threshold frac 0.01 0.0–0.25
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
fan_on_min Fan-on command threshold frac 0.01 0.0–0.25
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- param: mix_tol = 1.15 ; delta_supply_fan = 0.55
SELECT
  timestamp, equipment_id, sat, mat, htg_valve_pct, fan_cmd,
  CASE
    WHEN sat IS NULL OR mat IS NULL OR htg_valve_pct IS NULL OR fan_cmd IS NULL THEN false
    WHEN (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05
     AND (CASE WHEN htg_valve_pct > 1.0 THEN htg_valve_pct / 100.0 ELSE htg_valve_pct END) > 0.01
     AND (sat + 1.15) <= (mat - 1.15 + 0.55) THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

FC6 — Estimated OA fraction mismatch

Family: ahu · Equipment: ahu
Equation: |RATavg−OATavg| ≥ ΔTmin AND |estimated OA% − design min OA%| > εF.
Default confirmation: 600 s

Param Label Unit Default Range
eps_airflow Airflow error εF (GL36 default 30%) frac 0.15 0.05–1.0
delta_t_min Minimum |OAT−RAT| ΔTmin (GL36 default 10°F) °F 5.0 0.0–30.0
airflow_err Legacy OA-fraction error (sets εF) frac 0.15 0.05–1.0
oat_rat_delta_min Legacy OAT/RAT guard (sets ΔTmin) °F 5.0 0.0–30.0
min_cfm_design Design min OA CFM cfm 5000 500–20000
fan_on_min Fan-on command threshold frac 0.01 0.0–0.25
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC6 — Estimated OA fraction mismatch
-- equation: |RAT−OAT| ≥ 5°F AND |estimated OA% − design min OA%| > 15% in heating/mech-only modes.

SELECT
  timestamp,
  equipment_id,
  mixed_air_temp,
  outside_air_temp,
  return_air_temp,
  vav_total_airflow,
  CASE
    -- Implement FC6 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC7 — SAT low with full heating (GL36 E)

Family: ahu · Equipment: ahu
Equation: SATavg < SATSP − εSAT AND HC ≥ full-heating threshold.
Default confirmation: 600 s

Param Label Unit Default Range
eps_sat SAT sensor error εSAT (GL36 default 2°F) °F 1.0 0.0–10.0
sat_err Legacy SAT error (sets εSAT) °F 1.0 0.0–10.0
htg_full_min Full-heating threshold (GL36 99%) frac 0.9 0.5–1.0
fan_on_min Fan-on command threshold frac 0.01 0.0–0.25
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- htg_valve_pct >= HTG_FULL_MIN; fan_status then fan_cmd. sql_rules/fc7_sat_low_heating.sql
SELECT equipment_id, fault_hours FROM fc7_sat_low_heating_result

FC8 — SAT/MAT mismatch in economizer (GL36 F)

Family: ahu · Equipment: ahu
Equation: |SATavg − ΔTSF − MATavg| > √(εSAT² + εMAT²) in OS#2.
Default confirmation: 600 s

Param Label Unit Default Range
eps_sat SAT sensor error εSAT (GL36 default 2°F) °F 1.15 0.0–10.0
eps_mat MAT sensor error εMAT (GL36 default 5°F) °F 1.15 0.0–10.0
delta_supply_fan Supply-fan heat rise ΔTSF (GL36 default 2°F) °F 0.55 0.0–5.0
econ_min_pos Economizer minimum-position threshold frac 0.05 0.0–0.5
clg_inactive_max Cooling-command inactive ceiling frac 0.1 0.0–0.5
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
supply_tol Legacy SAT tolerance master (sets εSAT) °F 1.15 0.0–10.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC8 — SAT/MAT mismatch in economizer (GL36 F)
-- equation: Economizer open, CHW < 10%, |SAT − 0.55°F − MAT| > √(supply_tol²+mix_tol²).

SELECT
  timestamp,
  equipment_id,
  discharge_air_temp,
  mixed_air_temp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC8 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC9 — OAT too warm for free cooling (GL36 G)

Family: ahu · Equipment: ahu
Equation: OATavg − εOAT > SATSP − ΔTSF + εSAT in OS#2.
Default confirmation: 600 s

Param Label Unit Default Range
eps_oat OAT sensor error εOAT (GL36 default 2°F local / 5°F global) °F 1.15 0.0–10.0
eps_sat SAT sensor error εSAT (GL36 default 2°F) °F 1.15 0.0–10.0
delta_supply_fan Supply-fan heat rise ΔTSF (GL36 default 2°F) °F 0.55 0.0–5.0
econ_min_pos Economizer minimum-position threshold frac 0.05 0.0–0.5
clg_inactive_max Cooling-command inactive ceiling frac 0.1 0.0–0.5
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC9 — OAT too warm for free cooling (GL36 G)
-- equation: Economizer open, CHW < 10%, OAT − mix_tol > SAT SP − 0.55°F + mix_tol.

SELECT
  timestamp,
  equipment_id,
  outside_air_temp,
  discharge_air_temp_sp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC9 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC10 — OAT/MAT mismatch + mech cooling (GL36 H)

Family: ahu · Equipment: ahu
Equation: |MATavg − OATavg| > √(εMAT² + εOAT²) in OS#3.
Default confirmation: 600 s

Param Label Unit Default Range
eps_mat MAT sensor error εMAT (GL36 default 5°F) °F 1.15 0.0–10.0
eps_oat OAT sensor error εOAT (GL36 default 2°F local / 5°F global) °F 1.15 0.0–10.0
econ_full_open Economizer full-open threshold frac 0.9 0.5–1.0
clg_on_min Cooling-command ON threshold frac 0.01 0.0–0.25
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC10 — OAT/MAT mismatch + mech cooling (GL36 H)
-- equation: CHW > 1%, economizer > 90%, |MAT − OAT| > √(mix_tol²+mix_tol²).

SELECT
  timestamp,
  equipment_id,
  mixed_air_temp,
  outside_air_temp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC10 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC11 — OAT/MAT mismatch economizer-only (GL36 I)

Family: ahu · Equipment: ahu
Equation: OATavg + εOAT < SATSP − ΔTSF − εSAT in OS#3.
Default confirmation: 600 s

Param Label Unit Default Range
eps_oat OAT sensor error εOAT (GL36 default 2°F local / 5°F global) °F 1.15 0.0–10.0
eps_sat SAT sensor error εSAT (GL36 default 2°F) °F 1.15 0.0–10.0
delta_supply_fan Supply-fan heat rise ΔTSF (GL36 default 2°F) °F 0.55 0.0–5.0
econ_full_open Economizer full-open threshold frac 0.9 0.5–1.0
clg_on_min Cooling-command ON threshold frac 0.01 0.0–0.25
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC11 — OAT/MAT mismatch economizer-only (GL36 I)
-- equation: CHW > 1%, economizer > 90%, OAT + mix_tol < SAT SP − 0.55°F − mix_tol.

SELECT
  timestamp,
  equipment_id,
  outside_air_temp,
  discharge_air_temp_sp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC11 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC12 — SAT above blend in cooling (GL36 J)

Family: ahu · Equipment: ahu
Equation: SATavg − εSAT − ΔTSF ≥ MATavg + εMAT in OS#3/OS#4.
Default confirmation: 600 s

Param Label Unit Default Range
eps_sat SAT sensor error εSAT (GL36 default 2°F) °F 1.15 0.0–10.0
eps_mat MAT sensor error εMAT (GL36 default 5°F) °F 1.15 0.0–10.0
delta_supply_fan Supply-fan heat rise ΔTSF (GL36 default 2°F) °F 0.55 0.0–5.0
econ_min_pos Economizer minimum-position threshold frac 0.05 0.0–0.5
econ_full_open Economizer full-open threshold frac 0.9 0.5–1.0
clg_on_min Cooling-command ON threshold frac 0.01 0.0–0.25
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
supply_tol Legacy SAT tolerance master (sets εSAT) °F 1.15 0.0–10.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC12 — SAT above blend in cooling (GL36 J)
-- equation: CHW > 1%, SAT − supply_tol − 0.55°F > MAT + mix_tol at min or full economizer.

SELECT
  timestamp,
  equipment_id,
  discharge_air_temp,
  mixed_air_temp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC12 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC13 — SAT above SP at full cooling (GL36 K)

Family: ahu · Equipment: ahu
Equation: SATavg > SATSP + εSAT AND CC ≥ full-cooling threshold in OS#3/OS#4.
Default confirmation: 600 s

Param Label Unit Default Range
eps_sat SAT sensor error εSAT (GL36 default 2°F) °F 1.0 0.0–10.0
sat_err Legacy SAT error (sets εSAT) °F 1.0 0.0–10.0
clg_full_min Full-cooling threshold (GL36 99%) frac 0.01 0.5–1.0
econ_min_pos Economizer minimum-position threshold frac 0.05 0.0–0.5
econ_full_open Economizer full-open threshold frac 0.9 0.5–1.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC13 — SAT above SP at full cooling (GL36 K)
-- equation: CHW > 1%, SAT > SAT SP + 1.0°F at min or full economizer.

SELECT
  timestamp,
  equipment_id,
  discharge_air_temp,
  discharge_air_temp_sp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC13 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC14 — CHW coil ΔT when inactive (GL36 L)

Family: ahu · Equipment: ahu
Equation: Cooling-coil ΔT ≥ √(εCCET² + εCCLT²) + ΔTSF while coil should be inactive.
Default confirmation: 600 s

Param Label Unit Default Range
eps_ccet Cooling-coil entering sensor error εCCET °F 1.15 0.0–10.0
eps_cclt Cooling-coil leaving sensor error εCCLT °F 1.15 0.0–10.0
delta_supply_fan Supply-fan heat rise ΔTSF (GL36 default 2°F) °F 0.55 0.0–5.0
econ_min_pos Economizer minimum-position threshold frac 0.05 0.0–0.5
clg_inactive_max Cooling-command inactive ceiling frac 0.1 0.0–0.5
htg_on_min Heating-command ON threshold frac 0.01 0.0–0.25
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC14 — CHW coil ΔT when inactive (GL36 L)
-- equation: Cooling coil ΔT ≥ √(mix_tol²+mix_tol²)+0.55°F while coil should be inactive.

SELECT
  timestamp,
  equipment_id,
  cooling_coil_entering_temp,
  cooling_coil_leaving_temp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC14 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

FC15 — HW coil ΔT when inactive (GL36 M)

Family: ahu · Equipment: ahu
Equation: Heating-coil ΔT ≥ √(εHCET² + εHCLT²) + ΔTSF while coil should be inactive.
Default confirmation: 600 s

Param Label Unit Default Range
eps_hcet Heating-coil entering sensor error εHCET °F 1.15 0.0–10.0
eps_hclt Heating-coil leaving sensor error εHCLT °F 1.15 0.0–10.0
delta_supply_fan Supply-fan heat rise ΔTSF (GL36 default 2°F) °F 0.55 0.0–5.0
econ_min_pos Economizer minimum-position threshold frac 0.05 0.0–0.5
econ_full_open Economizer full-open threshold frac 0.9 0.5–1.0
clg_inactive_max Cooling-command inactive ceiling frac 0.1 0.0–0.5
clg_on_min Cooling-command ON threshold frac 0.01 0.0–0.25
mix_tol Legacy master sensor tolerance (sets all ε values) °F 1.15 0.0–10.0
mode_delay_min Mode-change suspension (GL36 default 30) min 0.0 0.0–60.0 
-- confirmation_seconds: 600
-- rule: FC15 — HW coil ΔT when inactive (GL36 M)
-- equation: Heating coil ΔT ≥ √(mix_tol²+mix_tol²)+0.55°F while coil should be inactive.

SELECT
  timestamp,
  equipment_id,
  heating_coil_entering_temp,
  heating_coil_leaving_temp,
  outside_air_damper,
  cooling_valve,
  CASE
    -- Implement FC15 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

AHU-SATDEV — SAT deviation from setpoint

Family: ahu · Equipment: ahu
Equation: |SAT − SAT SP| > 5°F.
Default confirmation: 600 s

Param Label Unit Default Range
sat_dev_err SAT deviation °F 5.0 1.0–15.0 
-- confirmation_seconds: 600
-- rule: AHU-SATDEV — SAT deviation from setpoint
-- equation: |SAT − SAT SP| > 5°F.

SELECT
  timestamp,
  equipment_id,
  discharge_air_temp,
  discharge_air_temp_sp,
  CASE
    -- Implement AHU-SATDEV against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

AHU-DUCTHI — Duct static pressure high

Family: ahu · Equipment: ahu
Equation: Duct static > static SP + margin. Evaluates when fan is proven on OR duct static itself exceeds pressure_on_min (catches high static with fan-status off).
Default confirmation: 300 s

Param Label Unit Default Range
duct_high_margin High margin in. w.c. 0.25 0.05–1.0
pressure_on_min Pressure-on evidence in. w.c. 0.2 0.05–1.0 
-- confirmation_seconds: 300
-- rule: AHU-DUCTHI — Duct static pressure high
-- equation: Duct static > static SP + margin. Evaluates when fan is proven on OR duct static itself exceeds pressure_on_min (catches high static with fan-status off).

SELECT
  timestamp,
  equipment_id,
  duct_static_pressure,
  duct_static_pressure_sp,
  CASE
    -- Implement AHU-DUCTHI against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

AHU-SIMUL — Heating and cooling simultaneous

Family: ahu · Equipment: ahu
Equation: Heating valve > 10% AND cooling valve > 10% at once.
Default confirmation: 300 s

Param Label Unit Default Range
valve_open_pct Valve open threshold frac 0.1 0.05–0.5 
-- confirmation_seconds: 300
-- rule: AHU-SIMUL — Heating and cooling simultaneous
-- equation: Heating valve > 10% AND cooling valve > 10% at once.

SELECT
  timestamp,
  equipment_id,
  heating_valve,
  cooling_valve,
  CASE
    -- Implement AHU-SIMUL against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

OAT-METEO — BAS outdoor-air sensor vs Open-Meteo

Family: ahu · Equipment: ahu
Equation: BAS OAT sensor differs from Open-Meteo dry bulb by more than 5°F.
Default confirmation: 900 s

Param Label Unit Default Range
oat_err Max OAT disagreement °F 5.0 2.0–20.0 
-- confirmation_seconds: 900
-- param: oat_err = 5.0
SELECT
  timestamp, equipment_id, oa_t, oat_meteo,
  CASE
    WHEN oa_t IS NULL OR oat_meteo IS NULL THEN false
    WHEN abs(oa_t - oat_meteo) > 5.0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

ECON-1 — Economizer stuck closed

Family: ahu · Equipment: ahu
Equation: Fan on, OA damper < 5%, OAT > 55°F (should be economizing).
Default confirmation: 600 s

Param Label Unit Default Range
econ1_oat_min Favorable OAT °F 55.0 45.0–70.0 
-- confirmation_seconds: 600
SELECT
  timestamp, equipment_id, oa_damper_pct, oa_t, mat, rat, fan_cmd,
  CASE
    WHEN oa_damper_pct IS NULL OR mat IS NULL OR oa_t IS NULL THEN false
    WHEN (CASE WHEN oa_damper_pct > 1.0 THEN oa_damper_pct / 100.0 ELSE oa_damper_pct END) <= 0.05
     AND abs(mat - oa_t) > 5.0
     AND (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

ECON-2 — Economizing when outdoor unfavorable

Family: ahu · Equipment: ahu
Equation: OAT > 63°F AND OA damper > 42% (should be at minimum).
Default confirmation: 300 s

Param Label Unit Default Range
econ2_oat_hi OAT high cutoff °F 63.0 55.0–80.0
econ2_damper Damper open frac frac 0.42 0.2–0.9 
-- confirmation_seconds: 300
-- rule: ECON-2 — Economizing when outdoor unfavorable
-- equation: OAT > 63°F AND OA damper > 42% (should be at minimum).

SELECT
  timestamp,
  equipment_id,
  outside_air_temp,
  outside_air_damper,
  CASE
    -- Implement ECON-2 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

ECON-3 — Mech cooling without integrated economizer

Family: ahu · Equipment: ahu
Equation: Web free-cooling opportunity (60°F ≤ DB < 72°F AND dewpoint < 60°F) while cooling valve open and OA damper below integrated threshold (default 90%).
Default confirmation: 300 s

Param Label Unit Default Range
econ3_db_min Free-cool OA dry-bulb min °F 60.0 50.0–68.0
econ3_db_max Free-cool OA dry-bulb max °F 72.0 65.0–80.0
econ3_dp_max Free-cool OA dew point max °F 60.0 45.0–68.0
econ3_damper_hi Integrated economizer damper frac 0.9 0.5–1.0 
-- confirmation_seconds: 300
SELECT
  timestamp, equipment_id, web_oa_t, web_oa_dp, oa_damper_pct, clg_valve_pct,
  CASE
    WHEN web_oa_t IS NULL OR web_oa_dp IS NULL OR oa_damper_pct IS NULL OR clg_valve_pct IS NULL THEN false
    WHEN web_oa_t >= 60.0 AND web_oa_t < 72.0 AND web_oa_dp < 60.0
     AND (CASE WHEN clg_valve_pct > 1.0 THEN clg_valve_pct / 100.0 ELSE clg_valve_pct END) > 0.01
     AND (CASE WHEN oa_damper_pct > 1.0 THEN oa_damper_pct / 100.0 ELSE oa_damper_pct END) < 0.90 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

ECON-4 — Low estimated OA fraction

Family: ahu · Equipment: ahu
Equation: Fan on, |RAT−OAT| > 2.2°F, estimated OA fraction < 21%.
Default confirmation: 600 s

Param Label Unit Default Range
oa_min_pct Min OA fraction % 21.0 5.0–40.0 
-- confirmation_seconds: 600
-- rule: ECON-4 — Low estimated OA fraction
-- equation: Fan on, |RAT−OAT| > 2.2°F, estimated OA fraction < 21%.

SELECT
  timestamp,
  equipment_id,
  mixed_air_temp,
  return_air_temp,
  outside_air_temp,
  fan_cmd,
  CASE
    -- Implement ECON-4 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

ECON-5 — Preheat over-conditioning

Family: ahu · Equipment: ahu
Equation: Preheat leaving air > 2.2°F above target while preheat active.
Default confirmation: 600 s

Param Label Unit Default Range
preheat_over_f Preheat over ΔT °F 2.2 0.5–8.0 
-- confirmation_seconds: 600
-- rule: ECON-5 — Preheat over-conditioning
-- equation: Preheat leaving air > 2.2°F above target while preheat active.

SELECT
  timestamp,
  equipment_id,
  preheat_leaving_temp,
  discharge_air_temp_sp,
  outside_air_temp,
  heating_valve,
  CASE
    -- Implement ECON-5 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

ECON-6 — Economizing in freezing weather

Family: ahu · Equipment: ahu
Equation: Web dry-bulb < 25°F AND OA damper above winter min-OA ceiling (default 25%). AHU should be at minimum OA in cold weather.
Default confirmation: 600 s

Param Label Unit Default Range
econ6_oat_max_f Winter OAT ceiling °F 25.0 15.0–40.0
econ6_damper_max Winter min-OA damper frac 0.25 0.05–0.5 
-- confirmation_seconds: 600
-- rule: ECON-6 — Economizing in freezing weather
-- equation: Web dry-bulb < 25°F AND OA damper above winter min-OA ceiling (default 25%). AHU should be at minimum OA in cold weather.

SELECT
  timestamp,
  equipment_id,
  outside_air_damper,
  CASE
    -- Implement ECON-6 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

ECON-7 — Economizer OK but not economizing

Family: ahu · Equipment: ahu
Equation: Economizer-OK web weather: dew point < 60°F AND dry-bulb < 72°F (above a 35°F freeze-guard floor; dewpoint from web sensor or calculated from web DB+RH). Fault when there is cooling demand (cooling valve open or proven DX/chiller cooling) but the OA damper stays below the economizing threshold (default 50%). Expected: economizer-only below 60°F DB (MECH-OAT-1) and mech + integrated economizer in the 60–72°F band (ECON-3). All thresholds are imperial sliders.
Default confirmation: 600 s

Param Label Unit Default Range
econ7_db_min Econ-OK dry-bulb floor (freeze guard) °F 35.0 20.0–50.0
econ7_db_max Econ-OK dry-bulb max °F 72.0 65.0–80.0
econ7_dp_max Econ-OK dew point max °F 60.0 45.0–68.0
econ7_damper_min Economizing damper threshold frac 0.5 0.2–0.9 
-- confirmation_seconds: 600
-- rule: ECON-7 — Economizer OK but not economizing
-- equation: Economizer-OK web weather: dew point < 60°F AND dry-bulb < 72°F (above a 35°F freeze-guard floor; dewpoint from web sensor or calculated from web DB+RH). Fault when there is cooling demand (cooling valve open or proven DX/chiller cooling) but the OA damper stays below the economizing threshold (default 50%). Expected: economizer-only below 60°F DB (MECH-OAT-1) and mech + integrated economizer in the 60–72°F band (ECON-3). All thresholds are imperial sliders.

SELECT
  timestamp,
  equipment_id,
  outside_air_damper,
  CASE
    -- Implement ECON-7 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

MECH-OAT-1 — Mechanical cooling below 60°F web OAT

Family: ahu · Equipment: ahu, chiller, heatpump
Equation: Proven DX/chiller mechanical cooling while web dry-bulb < 60°F. Uses compressor/chiller/pump/amps/power proof — not AHU cooling-valve alone. Below 60°F is outside the free-cool + integrated economizer band.
Default confirmation: 600 s

Param Label Unit Default Range
mech_oat_max_f Mech-cool OAT ceiling °F 60.0 45.0–65.0 
-- confirmation_seconds: 600
-- rule: MECH-OAT-1 — Mechanical cooling below 60°F web OAT
-- equation: Proven DX/chiller mechanical cooling while web dry-bulb < 60°F. Uses compressor/chiller/pump/amps/power proof — not AHU cooling-valve alone. Below 60°F is outside the free-cool + integrated economizer band.

SELECT
  timestamp,
  equipment_id,
  CASE
    -- Implement MECH-OAT-1 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

RESET-1 — SAT reset not tracking outdoor air

Family: ahu · Equipment: ahu
Equation: Fan on AND |SAT SP − (52 + 0.25×(OAT−65))| > 3°F.
Default confirmation: 900 s

No extra cookbook params beyond confirmation in this snippet; production SQL uses sql_rules/reset1_sat_oa_reset.sql.

-- confirmation_seconds: 900
-- See sql_rules/reset1_sat_oa_reset.sql
SELECT equipment_id, fault_hours FROM reset1_sat_oa_reset_result

CMD-1 — Fan cmd/status mismatch

Family: ahu · Equipment: ahu
Equation: Fan command and proven status disagree.
Default confirmation: 600 s

No tunable thresholds beyond confirmation delay.

-- confirmation_seconds: 600
SELECT
  timestamp, equipment_id, fan_cmd, fan_status,
  CASE
    WHEN fan_cmd IS NULL OR fan_status IS NULL THEN false
    WHEN ((CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05) <> fan_status THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

OA-1 — Low OA fraction

Family: ahu · Equipment: ahu
Equation: Estimated OA fraction < 15% with adequate OAT/RAT split.
Default confirmation: 900 s

Param Label Unit Default Range    
min_oa_frac Min OA fraction frac 0.15 0.05–0.4    
oat_rat_guard Min RAT−OAT guard °F 2.2 0.5–6.0 
-- confirmation_seconds: 900
-- param: min_oa_frac = 0.15 ; oat_rat_guard = 2.2
SELECT
  timestamp, equipment_id, mat, rat, oa_t, fan_cmd,
  CASE
    WHEN mat IS NULL OR rat IS NULL OR oa_t IS NULL THEN false
    WHEN abs(rat - oa_t) <= 2.2 THEN false
    WHEN (mat - rat) / NULLIF(oa_t - rat, 0) < 0.15
     AND (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

DMP-1 — OA damper leakage

Family: ahu · Equipment: ahu
Equation: Damper ≤ 5% but MAT tracks OAT within 2°F — leaking OA damper.
Default confirmation: 900 s

Param Label Unit Default Range
leak_delta Leak ΔT °F 2.0 0.5–6.0 
-- confirmation_seconds: 900
SELECT
  timestamp, equipment_id, oa_damper_pct, oa_t, mat,
  CASE
    WHEN oa_damper_pct IS NULL OR oa_t IS NULL OR mat IS NULL THEN false
    WHEN (CASE WHEN oa_damper_pct > 1.0 THEN oa_damper_pct / 100.0 ELSE oa_damper_pct END) <= 0.05
     AND abs(mat - oa_t) < 2.0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

VLV-1 — Cooling valve leakage

Family: ahu · Equipment: ahu
Equation: Cooling valve ≤ 5% AND (SAT < sat_sp − sat_err OR SAT < MAT − mat_leak_delta). Fan proven on when fan_status/fan_cmd present (operational gate).
Default confirmation: 900 s

Param Label Unit Default Range
sat_err SAT vs SP leak ΔT °F 2.0 0.5–8.0
mat_leak_delta SAT vs MAT leak ΔT °F 2.0 0.5–12.0 
-- confirmation_seconds: 900
SELECT
  timestamp, equipment_id, clg_valve_pct, sat, sat_sp, mat,
  CASE
    WHEN clg_valve_pct IS NULL OR sat IS NULL THEN false
    WHEN (CASE WHEN clg_valve_pct > 1.0 THEN clg_valve_pct / 100.0 ELSE clg_valve_pct END) <= 0.05
     AND (
       (sat_sp IS NOT NULL AND sat < sat_sp - 2.0)
       OR (mat IS NOT NULL AND sat < mat - 2.0)
     ) THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

VAV terminals

VAV-1 — Zone comfort band

Family: vav · Equipment: vav, zone
Equation: Zone temp < 70°F or > 75°F.
Default confirmation: 900 s

Param Label Unit Default Range
zone_lo Zone low °F 70.0 55.0–72.0
zone_hi Zone high °F 75.0 72.0–85.0 
-- confirmation_seconds: 900
-- param: comfort_low_f = 70 ; comfort_high_f = 75
SELECT
  timestamp, equipment_id, zone_t, occ_mode,
  CASE
    WHEN zone_t IS NULL THEN false
    WHEN lower(COALESCE(occ_mode, 'occupied')) = 'occupied'
     AND (zone_t < 70.0 OR zone_t > 75.0) THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-vav'

VAV-2 — Night setback miss

Family: vav · Equipment: vav, zone
Equation: Unoccupied AND zone temp > setback_hi (default 68°F).
Default confirmation: 900 s

Param Label Unit Default Range
setback_hi Setback high °F 68.0 55.0–72.0 
-- confirmation_seconds: 900
-- See sql_rules/vav2_night_setback.sql
SELECT equipment_id, fault_hours FROM vav2_night_setback_result

VAV-3 — Excessive reheat during warm weather

Family: vav · Equipment: vav
Equation: Air flowing AND OAT > 78°F AND reheat valve > 52%.
Default confirmation: 300 s

Param Label Unit Default Range
reheat_oat Warm OAT °F 78.0 65.0–90.0
reheat_pct Reheat frac frac 0.52 0.1–1.0
flow_on_min Airflow-on min cfm 25.0 0.0–200.0 
-- confirmation_seconds: 300
-- rule: VAV-3 — Excessive reheat during warm weather
-- equation: Air flowing AND OAT > 78°F AND reheat valve > 52%.

SELECT
  timestamp,
  equipment_id,
  outside_air_temp,
  reheat_valve,
  CASE
    -- Implement VAV-3 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

VAV-4 — Damper stuck at full open

Family: vav · Equipment: vav
Equation: Air flowing AND damper > 97.5% sustained across the window.
Default confirmation: 900 s

Param Label Unit Default Range
full_open_pct Full open frac frac 0.975 0.8–1.0
sustain_hours Sustain window h 1.5 0.5–6.0
flow_on_min Airflow-on min cfm 25.0 0.0–200.0 
-- Sequential: (1) sustain full-open streak (2) confirm that mask — not max(sustain, confirm).
-- See sql_rules/vav4_damper_full_open.sql
SELECT equipment_id, fault_hours FROM vav4_damper_full_open_result

VAV-5 — Airflow sensor bias

Family: vav · Equipment: vav
Equation: Airflow > 50 cfm while damper < 10% (implausible flow).
Default confirmation: 900 s

No tunable thresholds beyond confirmation delay.

-- confirmation_seconds: 900
-- rule: VAV-5 — Airflow sensor bias
-- equation: Airflow > 50 cfm while damper < 10% (implausible flow).

SELECT
  timestamp,
  equipment_id,
  zone_airflow,
  damper,
  CASE
    -- Implement VAV-5 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

VAV-6 — Reheat when cooling available

Family: vav · Equipment: vav
Equation: OAT < 65°F AND reheat valve > 25% (optional cooling-available).
Default confirmation: 900 s

Param Label Unit Default Range
free_cool_oat Free-cool OAT °F 65.0 45.0–75.0
reheat_pct Reheat frac frac 0.25 0.05–1.0 
-- confirmation_seconds: 900
-- See sql_rules/vav6_reheat_free_cool.sql
SELECT equipment_id, fault_hours FROM vav6_reheat_free_cool_result

VAV-REHEAT — Reheat valve stuck / no temp rise

Family: vav · Equipment: vav
Equation: Air flowing AND reheat valve > 30% AND box discharge temp rises < 3°F above duct inlet (air from AHU) — stuck or failed reheat valve/coil.
Default confirmation: 900 s

Param Label Unit Default Range
reheat_cmd Reheat open frac frac 0.3 0.1–1.0
min_rise Min temp rise °F 3.0 0.5–15.0
flow_on_min Airflow-on min cfm 25.0 0.0–200.0 
-- confirmation_seconds: 900
-- rule: VAV-REHEAT — Reheat valve stuck / no temp rise
-- equation: Air flowing AND reheat valve > 30% AND box discharge temp rises < 3°F above duct inlet (air from AHU) — stuck or failed reheat valve/coil.

SELECT
  timestamp,
  equipment_id,
  reheat_valve,
  vav_discharge_air_temp,
  vav_inlet_air_temp,
  CASE
    -- Implement VAV-REHEAT against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

VAV-AHU-LEAVE — VAV leave vs parent AHU SAT (fedBy)

Family: vav · Equipment: vav
Equation: Air flowing AND |VAV discharge − parent AHU SAT| > band. Needs package topology (vav_to_ahu) so ahu_sat is enriched from the fedBy AHU; otherwise SKIPPED_MISSING_ROLES. Flags broken reheat, bad sensors, or rogue zones.
Default confirmation: 900 s

Param Label Unit Default Range
delta_f Leave Δ vs AHU SAT °F 8.0 2.0–25.0
flow_on_min Airflow-on min cfm 25.0 0.0–200.0 
-- confirmation_seconds: 900
-- rule: VAV-AHU-LEAVE — VAV leave vs parent AHU SAT (fedBy)
-- equation: Air flowing AND |VAV discharge − parent AHU SAT| > band. Needs package topology (vav_to_ahu) so ahu_sat is enriched from the fedBy AHU; otherwise SKIPPED_MISSING_ROLES. Flags broken reheat, bad sensors, or rogue zones.

SELECT
  timestamp,
  equipment_id,
  vav_discharge_air_temp,
  ahu_discharge_air_temp,
  CASE
    -- Implement VAV-AHU-LEAVE against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

VAV-7 — Min airflow / fixed high flow

Family: vav · Equipment: vav
Equation: Flow below min SP (when mapped), OR airflow stays flat (low rolling std) at a high mean while air is on (mins too high / box never modulates), OR min_flow_sp itself is excessively high.
Default confirmation: 900 s

Param Label Unit Default Range
flow_on_min Airflow-on min cfm 25.0 0.0–200.0
fixed_flow_max_std Fixed-flow max std cfm 15.0 1.0–80.0
fixed_flow_min_mean Fixed-flow min mean cfm 200.0 50.0–2000.0
high_min_flow_sp High min-flow SP cfm 250.0 50.0–2000.0 
-- confirmation_seconds: 900
-- Three pandas branches: under-min OR fixed-high rolling std/mean OR high min_flow_sp.
-- SQL: sql_rules/vav7_min_airflow.sql (timestamp-ordered windows).
SELECT equipment_id, fault_hours FROM vav7_min_airflow_result

Central plant / condenser water

CHW-NOLOAD-1 — Chiller running with no building load

Family: plant · Equipment: chiller
Equation: Chiller/plant proven running while building load is satisfied: all mapped zones inside comfort band OR all mapped AHU SAT within sat_band of setpoint. Default confirm 30 min.
Default confirmation: 1800 s

Param Label Unit Default Range
comfort_low_f Comfort low °F 70.0 60.0–78.0
comfort_high_f Comfort high °F 75.0 68.0–85.0
sat_band_f AHU SAT≈SP band °F 2.0 0.5–6.0 
-- confirmation_seconds: 1800
-- rule: CHW-NOLOAD-1 — Chiller running with no building load
-- equation: Chiller/plant proven running while building load is satisfied: all mapped zones inside comfort band OR all mapped AHU SAT within sat_band of setpoint. Default confirm 30 min.

SELECT
  timestamp,
  equipment_id,
  CASE
    -- Implement CHW-NOLOAD-1 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

CHW-1 — Low chilled-water ΔT

Family: plant · Equipment: chiller
Equation: Pump on AND (CHWR − CHWS) < 4°F.
Default confirmation: 900 s

Param Label Unit Default Range
min_dt Min ΔT °F 4.0 1.0–12.0 
-- confirmation_seconds: 900
-- param: min_dt = 4.0
SELECT
  timestamp, equipment_id, chw_supply_t, chw_return_t, chw_pump_cmd,
  CASE
    WHEN chw_supply_t IS NULL OR chw_return_t IS NULL THEN false
    WHEN chw_pump_cmd IS NOT NULL
     AND (CASE WHEN chw_pump_cmd > 1.0 THEN chw_pump_cmd / 100.0 ELSE chw_pump_cmd END) <= 0.05 THEN false
    WHEN (chw_return_t - chw_supply_t) < 4.0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-chw-plant'

CHW-2 — DP below SP at max pump speed

Family: plant · Equipment: chiller
Equation: Pump ≥ 87% AND CHW DP < DP SP − 2.2.
Default confirmation: 300 s

Param Label Unit Default Range
dp_margin DP margin psi 2.2 0.5–6.0
pump_hi Pump high-speed threshold frac 0.87 0.5–1.0 
-- confirmation_seconds: 300
-- rule: CHW-2 — DP below SP at max pump speed
-- equation: Pump ≥ 87% AND CHW DP < DP SP − 2.2.

SELECT
  timestamp,
  equipment_id,
  chw_diff_pressure,
  chw_diff_pressure_sp,
  chw_pump_cmd,
  CASE
    -- Implement CHW-2 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

CHW-3 — Plant supply temp outside deadband

Family: plant · Equipment: chiller
Equation: Pump on AND |CHWS − CHWS SP| > 2.2°F.
Default confirmation: 300 s

Param Label Unit Default Range
sp_band SP band °F 2.2 0.5–6.0 
-- confirmation_seconds: 300
-- rule: CHW-3 — Plant supply temp outside deadband
-- equation: Pump on AND |CHWS − CHWS SP| > 2.2°F.

SELECT
  timestamp,
  equipment_id,
  chilled_water_supply_temp,
  chilled_water_supply_temp_sp,
  chw_pump_cmd,
  CASE
    -- Implement CHW-3 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

CHW-4 — Flow high at max pump

Family: plant · Equipment: chiller
Equation: Pump ≥ 87% AND CHW flow > 1100 gpm.
Default confirmation: 300 s

Param Label Unit Default Range
flow_hi Flow high gpm 1100 200–3000
pump_hi Pump high-speed threshold frac 0.87 0.5–1.0 
-- confirmation_seconds: 300
-- rule: CHW-4 — Flow high at max pump
-- equation: Pump ≥ 87% AND CHW flow > 1100 gpm.

SELECT
  timestamp,
  equipment_id,
  chw_flow,
  chw_pump_cmd,
  CASE
    -- Implement CHW-4 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

CW-OPT-1 — Condenser water not optimized vs wet-bulb

Family: plant · Equipment: chiller, cooling_tower
Equation: CW supply significantly colder than web wet-bulb + design approach (Stull WB) — tower over-cooling / not optimized.
Default confirmation: 900 s

Param Label Unit Default Range
cw_approach Design approach °F 7.0 3.0–15.0
cw_slack Slack below target °F 2.0 0.5–6.0 
-- confirmation_seconds: 900
-- rule: CW-OPT-1 — Condenser water not optimized vs wet-bulb
-- equation: CW supply significantly colder than web wet-bulb + design approach (Stull WB) — tower over-cooling / not optimized.

SELECT
  timestamp,
  equipment_id,
  condenser_water_supply_temp,
  CASE
    -- Implement CW-OPT-1 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

CW-APR-1 — High CW approach at full tower fan

Family: plant · Equipment: chiller, cooling_tower
Equation: At full tower fan speed, leaving CW − web wet-bulb exceeds approach_max (default 8°F, typically 5–10°F). Suspect OA→wet-bulb / CW sensor mismatch or cooling-tower performance degradation.
Default confirmation: 900 s

Param Label Unit Default Range
approach_max_f Max approach at full fan °F 8.0 5.0–15.0
tower_fan_hi Tower fan full-speed threshold frac 0.95 0.8–1.0 
-- confirmation_seconds: 900
-- rule: CW-APR-1 — High CW approach at full tower fan
-- equation: At full tower fan speed, leaving CW − web wet-bulb exceeds approach_max (default 8°F, typically 5–10°F). Suspect OA→wet-bulb / CW sensor mismatch or cooling-tower performance degradation.

SELECT
  timestamp,
  equipment_id,
  condenser_water_supply_temp,
  CASE
    -- Implement CW-APR-1 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

CW-FAN-1 — Excess tower fan energy vs wet-bulb limit

Family: plant · Equipment: chiller, cooling_tower
Equation: Tower fans at full speed while leaving CW is well above web wet-bulb + design approach (approach + excess_beyond). Fans are chasing a CW temp that is theoretically hard/impossible — excess fan energy.
Default confirmation: 900 s

Param Label Unit Default Range
cw_approach Design approach °F 7.0 3.0–15.0
excess_beyond_approach_f Excess beyond approach °F 5.0 2.0–20.0
tower_fan_hi Tower fan full-speed threshold frac 0.95 0.8–1.0 
-- confirmation_seconds: 900
-- rule: CW-FAN-1 — Excess tower fan energy vs wet-bulb limit
-- equation: Tower fans at full speed while leaving CW is well above web wet-bulb + design approach (approach + excess_beyond). Fans are chasing a CW temp that is theoretically hard/impossible — excess fan energy.

SELECT
  timestamp,
  equipment_id,
  condenser_water_supply_temp,
  CASE
    -- Implement CW-FAN-1 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

Heat pumps

HP-1 — Discharge cold when heating

Family: heatpump · Equipment: heatpump
Equation: Fan on, zone < 69°F, discharge SAT < 85°F.
Default confirmation: 600 s

Param Label Unit Default Range
min_sat Min heating SAT °F 85.0 70.0–110.0
zone_cold Zone cold °F 69.0 60.0–72.0 
-- confirmation_seconds: 600
SELECT
  timestamp, equipment_id, sat, zone_t, fan_cmd,
  CASE
    WHEN sat IS NULL OR zone_t IS NULL OR fan_cmd IS NULL THEN false
    WHEN (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05
     AND zone_t < 69.0 AND sat < 85.0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-heatpump'

Weather station

WX-1 — OA temperature spike

Family: weather · Equipment: weather
Equation: OAT sample-to-sample jump > 16°F.
Default confirmation: 300 s

Param Label Unit Default Range
spike_limit Spike limit °F 16.0 4.0–40.0 
-- confirmation_seconds: 300
SELECT
  timestamp, equipment_id, oa_t,
  CASE
    WHEN oa_t IS NULL THEN false
    WHEN abs(oa_t - lag(oa_t) OVER (ORDER BY timestamp)) > 16.0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:weather'

Trim & respond advisory

TRIM-1 — Duct static trim advisory

Family: trim · Equipment: ahu
Equation: Duct static high (> 1.35 in.w.c.) while VAV pressure requests are low.
Default confirmation: 1800 s

Param Label Unit Default Range
duct_hi Duct static high in. w.c. 1.35 0.5–3.0
request_lo Request sum low count 1.0 0.0–10.0 
-- confirmation_seconds: 1800
-- Advisory: duct static SP high while requests low (trim candidate)
SELECT
  timestamp, equipment_id, duct_static_sp, static_reset_request,
  CASE
    WHEN duct_static_sp IS NULL THEN false
    WHEN duct_static_sp > 1.2 AND COALESCE(static_reset_request, 0) <= 0 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

TRIM-3 — HWST trim advisory

Family: trim · Equipment: boiler
Equation: HW supply > 160°F while reset requests are low.
Default confirmation: 1800 s

Param Label Unit Default Range
hwst_hi HWST high °F 160.0 120.0–200.0
request_lo Request sum low count 1.0 0.0–10.0 
-- confirmation_seconds: 1800
-- rule: TRIM-3 — HWST trim advisory
-- equation: HW supply > 160°F while reset requests are low.

SELECT
  timestamp,
  equipment_id,
  hot_water_supply_temp,
  hw_reset_request_sum,
  CASE
    -- Implement TRIM-3 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

TRIM-4 — CHW plant reset advisory

Family: trim · Equipment: chiller
Equation: CHW supply < 45°F while reset requests are low.
Default confirmation: 1800 s

Param Label Unit Default Range
chw_lo CHWS low °F 45.0 35.0–55.0
request_lo Request sum low count 1.0 0.0–10.0 
-- confirmation_seconds: 1800
-- rule: TRIM-4 — CHW plant reset advisory
-- equation: CHW supply < 45°F while reset requests are low.

SELECT
  timestamp,
  equipment_id,
  chilled_water_supply_temp,
  chw_reset_request_sum,
  CASE
    -- Implement TRIM-4 against assigned Haystack → FDD columns
    -- NULL samples must not latch faults
    WHEN false THEN false  -- stub: never latch until equation is coded
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-id'

Schedule & occupancy

SCHED-1 — Unoccupied runtime

Family: schedule · Equipment: ahu
Equation: Fan running while occupancy is unoccupied (Overview calendar → occ_mode). When zone_t is mapped, also require zone inside comfort_low_f…comfort_high_f (defaults 70–75°F; synced from Overview zone band).
Default confirmation: 1800 s

Param Label Unit Default Range
comfort_low_f Comfort low °F 70.0 60.0–78.0
comfort_high_f Comfort high °F 75.0 68.0–85.0 
-- confirmation_seconds: 1800
SELECT
  timestamp, equipment_id, occ_mode, fan_status,
  CASE
    WHEN occ_mode IS NULL OR fan_status IS NULL THEN false
    WHEN lower(occ_mode) = 'unoccupied' AND fan_status THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

SCHED-247 — Always-on fan or pump runtime

Family: schedule · Equipment: ahu, vav, chiller, boiler, heatpump
Equation: Fan or pump (or similar motor proof/command) is on for ≥ always_on_pct of the analysis window — highlights equipment that appears to run 24/7. Applies to all fans and pumps regardless of equipment family when a status/cmd role is mapped.
Default confirmation: 3600 s

Param Label Unit Default Range
always_on_pct Always-on fraction frac 0.95 0.8–1.0
pressure_on_min Pressure-on evidence eng 0.2 0.05–2.0 
-- confirmation_seconds: 3600
-- Always-on screen: fan/pump command stays ON across the evaluation window
SELECT
  timestamp, equipment_id, fan_cmd,
  CASE
    WHEN fan_cmd IS NULL THEN false
    WHEN (CASE WHEN fan_cmd > 1.0 THEN fan_cmd / 100.0 ELSE fan_cmd END) >= 0.05 THEN true
    ELSE false
  END AS fault_raw
FROM telemetry_pivot
WHERE equipment_id = 'equip:your-ahu'

Not yet in validated catalog

Documented for continuity — not in the current validated vibe19 catalog.

ID Title Family
TOWER-1 Cooling tower approach high plant
CTRL-2 Generic control loop hunting control
OVR-1 Persistent override ahu
OA-2 DCV minimum OA not met ahu
PLANT-1 CHW DP reset missing plant
SP-HIGH Occupied setpoint too high vav
SP-LOW Occupied setpoint too low vav
KPI-1 Performance score (advisory) site
TRIM-2 Chiller plant enable advisory trim
WX-2 Gust lower than sustained wind weather

Framework & parity docs