Operating Modes

ACRouter has seven operating modes. Set one with POST /api/mode {"mode":"<name>"}, the web app, or the serial console (see Terminal Commands).

4.1 Modusübersicht

The grid and solar roles are assigned per rbAmp channel during Commissioning. The grid role must be a voltage-capable module so it reports signed power (import vs. export).

The Dashboard exposes six mode buttons; GRID_LIMIT is reached only through the API.

The web app exposes six mode buttons (OFF/AUTO/ECO/OFFGRID/MANUAL/BOOST). GRID_LIMIT is an advanced mode reached through the device API, not a Dashboard button.

Seven modes, from full automatic solar routing (AUTO) to manual and grid-cap control.

4.2 OFF

The system stops regulating and de-energizes the whole cascade — all dimmers go to 0% and all relays open. Measurement, web app, and serial keep working. Use for maintenance or to disconnect the load.

curl -X POST http://192.168.4.1/api/mode -d '{"mode":"off"}'

4.3 AUTO — Automatic Solar Router (primary)

Balances grid power to zero: it raises the dimmer when you'd otherwise export, and lowers it when you'd import, so all solar surplus is consumed locally.

AUTO regulates in both directions to zero; ECO only trims import; GRID_LIMIT caps grid current.

The controller nudges the level proportionally toward P_grid → 0 each cycle (~5 Hz) and holds inside a small balance dead-zone. (Advanced: the proportional control_gain and the balance_threshold dead-zone are tunable via POST /api/config; defaults suit most installs.)

With multiple loads, AUTO runs a priority cascade: it fills the highest-priority dimmer first and spills surplus to the next dimmer as each saturates; for large surpluses it also switches on GPIO relays (by priority). Set per-device priority with dimmer-priority / relay-priority.

In AUTO, surplus fills the highest-priority dimmer first and spills to the next device; relays switch on for large surpluses.

Example — solar surplus

PV 3000 W, house 800 W, a 3 kW heater  →  surplus 2200 W (would export), dimmer 0%
AUTO raises the dimmer until the heater draws ~2200 W (≈ 73% of 3 kW)
→ P_grid ≈ 0 W  ✅ balanced — all surplus heats water

Example — a cloud passes

Balanced: PV 2500 W, house 500 W, heater ~2000 W, P_grid ≈ 0 W
Cloud:    PV drops to 1500 W → the load starts pulling from the grid
AUTO lowers the heater to ~1000 W (surplus = 1500 − 500)  →  P_grid ≈ 0 W  ✅ new balance

curl -X POST http://192.168.4.1/api/mode -d '{"mode":"auto"}'

4.4 ECO — Anti-Import

ECO avoids drawing from the grid but allows export. When the site is importing it lowers the dimmer to stop buying power; when exporting or balanced it holds and does not chase the surplus (that surplus is exported).

AUTO vs. ECO: AUTO drives P_grid → 0 in both directions and consumes all surplus locally; ECO only trims on import and leaves export untouched (goal P_grid ≤ 0), and responds more gently (slower than AUTO for stability). Use ECO when export is acceptable (you have a feed-in tariff) but you don't want to pay for grid import under the diverted load.

Example

Exporting (PV 2000 W, house 1000 W → P_grid −1000 W): ECO HOLDS the dimmer — the surplus exports (fine in ECO).
Importing (dimmer already ~60%, a cloud pushes P_grid to +400 W): ECO LOWERS the dimmer until the import
stops (P_grid ≈ 0). It never raises the dimmer to chase export.

curl -X POST http://192.168.4.1/api/mode -d '{"mode":"eco"}'

Lose the regulating sensor and the controller ramps the load down to zero (~20 s) rather than holding it.

🔴 Sensor-loss failsafe (AUTO / ECO / GRID_LIMIT). If the regulating sensor goes stale or is lost (grid power in AUTO/ECO, grid current in GRID_LIMIT), or all sources fall silent, the controller does not hold the last level — it decays the dimmer toward 0% (≈ −1% per control cycle, ~20 s to zero on the 5 Hz path). OFFGRID decays the same way when solar is lost; OFF / MANUAL / BOOST hold their setpoints. Still keep a reliable CT connection and an external emergency disconnect (a contactor) as defense-in-depth.

4.5 OFFGRID — Autonomous

For systems with no grid connection. OFFGRID needs a solar measurement channel (not grid; it can be an rbAmp or an ESP-NOW node) and ignores the grid.

OFFGRID ramps the load up toward 80% of solar and holds high while the sun lasts, decaying to zero only when solar is lost.

How it regulates (one-way ramp). While solar generation is above a small threshold (~10 W), it ramps the dimmer up each cycle toward using 80% of the measured solar power (a hardcoded 20% headroom, not configurable), climbing to 100% if solar allows. It only ramps down when solar falls below the threshold — then it decays to 0. So under steady sun it sits near the top of its range rather than tracking a moving 0.8 × solar setpoint. It tracks solar only — it does not sense battery charge, so on a battery system a heavy house load can still pull from the battery.

Example

Steady sun (PV 1500 W): the dimmer ramps up toward 0.8 × 1500 ≈ 1200 W and holds high while sun lasts.
PV dips a bit (still above threshold): the dimmer stays up — it does NOT chase 0.8×PV down.
Solar gone (PV < ~10 W): the dimmer decays to 0%.

curl -X POST http://192.168.4.1/api/mode -d '{"mode":"offgrid"}'

4.6 MANUAL

The dimmer holds a fixed user level (0–100%) with no automation. Use for testing or a fixed schedule (e.g. 100% on a cheap night tariff).

curl -X POST http://192.168.4.1/api/manual -d '{"value":75}'   # sets level + switches to MANUAL

4.7 BOOST — Forced Heating

Dimmer forced to 100% regardless of sensors — maximum power to the load. Use for fast heating on a cheap tariff. ⚠️ High grid consumption; watch load temperature and don't leave unattended.

curl -X POST http://192.168.4.1/api/mode -d '{"mode":"boost"}'

4.8 GRID_LIMIT — Grid-Consumption Cap

GRID_LIMIT caps how much the site draws from the grid by current (current-based, no export). It keeps the grid current at or below grid_current_limit amps — useful to stay under a supply or breaker limit. Set the cap first, then the mode:

curl -X POST http://192.168.4.1/api/config -d '{"grid_current_limit": 16.0}'   # amps (default 16.0)
curl -X POST http://192.168.4.1/api/mode   -d '{"mode":"grid_limit"}'

How it regulates: GRID_LIMIT is bidirectional — it raises the dimmer to use up the headroom below the cap and backs it off when grid current exceeds the cap. It needs a grid current reading (no reading → it idles). If the house load alone already exceeds the cap, the dimmer goes to 0 (it can only shed the load it controls, not the house). It works on current magnitude and assumes no export / PV back-feed — using it on a site that exports is the user's responsibility.

GRID_LIMIT is an advanced mode reached through the API — it is not a Dashboard button.

4.9 Sensor Roles per Mode

Modes rely on rbAmp channel roles, not on wiring specifics (assign roles during Commissioning):

Voltage-capable vs. current-capable grid. AUTO and ECO need a voltage-capable grid module — they act on signed power, so they must tell import from export. GRID_LIMIT works on grid current magnitude only (no voltage, no direction), so a current-only rbAmp is enough; it assumes there is no export / PV back-feed (grid current = import) and reports 0 W for grid power.

Minimum solar-router config (AUTO/ECO): one voltage-capable rbAmp as grid, plus one DimmerLink (role=dimmer). Add a solar channel to enable OFFGRID.

Which kit unlocks which modes. The three ACRouter kits map directly onto this role model — every kit includes a temperature-controlled DimmerLink; the rbAmp channels are what add the closed-loop modes:

Both K1 and K2 ship a voltage-capable grid module, so both do AUTO / ECO / GRID_LIMIT (AUTO and ECO act on signed power — import vs. export — while GRID_LIMIT needs only grid current). K2 adds the solar channel that OFFGRID requires. See Overview §1.7 for the buyer-facing kit comparison.

4.10 Switching Modes

Switching is safe at any time — the controller resets its state and applies the new mode's logic. A few transitions to be aware of:

• → BOOST jumps straight to 100% (a sharp power spike).
• → OFFGRID relies on a solar channel; without one it can't regulate.

Set a mode via POST /api/mode, the web app's mode buttons, or the serial console (router-mode <name>; router-grid-limit <A> for the GRID_LIMIT cap — see Terminal Commands). Tuning parameters control_gain · balance_threshold · grid_current_limit go through POST /api/config; the MANUAL level goes through POST /api/manual (not /api/config) — see the Web API.

Setting a mode without its required sensor is not rejected. POST /api/mode returns 200 even if the required role is missing (e.g. OFFGRID with no solar channel, AUTO with no grid). The mode won't regulate — and because the required reading is absent, the failsafe decays the dimmer to 0 (it does not hold the load). Assign the required role first (see Commissioning) and verify the sign before relying on it.