Keep a site within its electrical limits

Ten 22 kW chargers behind a 63 A supply cannot all run flat out at once, and they don't need to. Flowion shares each circuit's current between the cars that are actually charging, moves it as cars arrive and leave, and keeps the total within the ratings you gave it. You install more chargers on the same fuse instead of paying for a bigger connection.

It starts from your circuit tree: once the circuits are rated and each outlet is attached to its circuit, sharing runs on its own. There is nothing to switch on.

Not supported on every charger: a charger has to accept the limits Flowion sends it. See which.

How Flowion shares a circuit

Every 30 seconds, for every circuit tree, Flowion:

• Shares what is free equally between the cars that want more.

• Respects every circuit above a car. A car's allowance is capped by the tightest circuit between it and the grid, line by line. A single-phase charger on a recorded line only uses capacity on that line.

• Takes back what a car is not using. A car that tapers off as its battery fills, or draws 6 A of a 16 A allowance, gives the rest back to the others.

• Always sends a reduction. A lower limit goes out even to a charger that has been refusing higher ones.

• Never hands out less than 6 A. Cars cannot charge below that, and some end the session if asked to. When there is not enough to go round, a car is paused at 0 A rather than given a trickle.

Leave room for the rest of the building

On a circuit that also feeds lights, heat pumps or a kitchen, add an energy monitor to it. Flowion then reserves what the rest of the building is measured drawing, line by line, and shares only what is left.

If the monitor's readings stop arriving, Flowion pauses the chargers under that circuit until they come back, rather than guess at what the building is drawing.

Watch it work

GET /locations/{locationId}/supply shows every circuit's draw per line and, for each charger, what it draws, what Flowion allows it and why. The allocation log records every change. Both are described in Model a site's circuits.

To give some sessions room ahead of others, see Let flexible sessions wait.

Set a fixed ceiling on a charger

A charging limit is a ceiling you install on one charger yourself — for example, at most 16 A for eight hours every night from 20:00 UTC, whatever the circuit has to spare:

curl -X POST "$API/charging-stations/$CHARGER/charging-limits" \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"scope": {"type": "stationLimit"},
       "priority": 10,
       "recurrence": "daily",
       "schedule": {"unit": "amps",
                    "anchor": "2026-10-01T20:00:00Z",
                    "durationSeconds": 28800,
                    "periods": [{"offsetSeconds": 0, "limit": 16}]}}'

{
  "accepted": true,
  "limit": {
    "id": "7d0b3e9a-41c6-4f2e-9a85-c3e1d6b2f740",
    "scope": {"type": "stationLimit"},
    "priority": 10,
    "recurrence": "daily",
    "schedule": {
      "unit": "amps",
      "anchor": "2026-10-01T20:00:00Z",
      "durationSeconds": 28800,
      "periods": [{"offsetSeconds": 0, "limit": 16}]
    }
  }
}

What the fields mean:

The call waits for the charger's answer, for up to about 35 seconds:

• 201 — the charger accepted it, and limit is the installed limit.

• 200 with accepted: false — the charger refused it; nothing was installed.

• 409 notConnected — the charger is offline. Try again once it is back.

• 422 exceedsCapability — the limit is more than this charger says it can hold; 422 invalidSchedule — recurrence and anchor disagree.

• 504 — no answer in time. Retry with the same Idempotency-Key: the retry never installs a second copy.

List what you installed (this answers from Flowion's record, so it works while the charger is offline), and remove a limit by id:

curl "$API/charging-stations/$CHARGER/charging-limits" \
  -H "Authorization: Bearer $TOKEN"

curl -X DELETE "$API/charging-stations/$CHARGER/charging-limits/$LIMIT" \
  -H "Authorization: Bearer $TOKEN"

DELETE /charging-stations/{id}/charging-limits without an id removes every limit matching optional scope, connectorId and priority filters — or all of them.

Cap one session

A charging limit caps the rate. To cap the total — energy, time or state of charge — set a session limit instead. Both can be set as you start a session: see Start and stop sessions remotely.

When a charger stops taking limits

A charger that refuses several limits in a row is marked as not accepting them: actuationStatus.acceptsLimits on the charger reads notAccepting. Flowion keeps sending it lower limits, holds back higher ones, and tries a higher one again every 30 minutes.

Once you have fixed the cause — new firmware, a replaced unit — clear the mark so Flowion tries again on its next pass:

curl -X DELETE "$API/charging-stations/$CHARGER/actuation-status" \
  -H "Authorization: Bearer $TOKEN"

If a breaker trips

Check the model against the site:

1. Does the circuit tree match the wiring? Ratings, phases and which circuit feeds which.

2. Is every outlet attached to its circuit? An outlet on no circuit is not balanced.

3. Are single-phase outlets on the lines you recorded? A wrong line puts the load where Flowion is not counting it.

4. Does the circuit feed anything besides chargers? Then it needs an energy monitor, or a rating that leaves room for the rest.

5. Is any charger marked notAccepting? Limits it refuses do not apply to it.

Endpoints

Locations & Circuits · Charging Limits · Charging Priority