Control via Homey Script

[0ge]

I was trying to make a load balancer and figured it would be easiest to do this via Homey Script.
I ran into some issues with controlling the Zaptec though: it seems you cannot set the current. (Either the installation or per phase)

Phase currents are not listed as a capability, and if I try to set the available_installation_current, it says it is not setable.

Is HomeyScript the wrong approach?
It felt a little cumbersome to do this with cards, especially if you want to add more complexity such as electricity prices or power tariff avoidance.

log(box.capabilitiesObj);
await box.setCapabilityValue("available_installation_current", i_limit)
  .then(() => log("OK!"))
  .catch(error => log(error));

Capabilities

{
  'meter_power.current_session': {
    value: null,
    lastUpdated: 2026-04-15T04:54:30.726Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Energy current session',
    desc: 'Energy usage in kilowatt-hour (kWh)',
    units: 'kWh',
    decimals: 2,
    chartType: 'spline',
    id: 'meter_power.current_session',
    options: { title: [Object] }
  },
  meter_power: {
    value: 0.08,
    lastUpdated: 2026-04-14T13:03:09.820Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Energy this year',
    desc: 'Energy usage in kilowatt-hour (kWh)',
    units: 'kWh',
    decimals: 2,
    chartType: 'spline',
    id: 'meter_power',
    options: { title: [Object] }
  },
  'meter_power.last_session': {
    value: 0.08,
    lastUpdated: 2026-04-14T13:03:10.791Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Energy previous session',
    desc: 'Energy usage in kilowatt-hour (kWh)',
    units: 'kWh',
    decimals: 2,
    chartType: 'spline',
    id: 'meter_power.last_session',
    options: { title: [Object] }
  },
  measure_power: {
    value: 0,
    lastUpdated: 2026-04-14T13:03:10.566Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Power',
    desc: 'Power in watt (W)',
    units: 'W',
    decimals: 2,
    chartType: 'stepLine',
    id: 'measure_power',
    options: {}
  },
  charging_button: {
    value: false,
    lastUpdated: 2026-04-14T13:04:31.153Z,
    type: 'boolean',
    getable: true,
    setable: true,
    title: 'Charging',
    desc: null,
    units: null,
    id: 'charging_button',
    options: {}
  },
  cable_permanent_lock: {
    value: null,
    lastUpdated: null,
    type: 'boolean',
    getable: true,
    setable: true,
    title: 'Cable locked',
    desc: null,
    units: null,
    id: 'cable_permanent_lock',
    options: {}
  },
  charge_mode: {
    value: 'Disconnected',
    lastUpdated: 2026-04-14T13:03:10.739Z,
    type: 'enum',
    getable: true,
    setable: false,
    title: 'Charger operation mode',
    desc: null,
    units: null,
    values: [ [Object], [Object], [Object], [Object], [Object] ],
    id: 'charge_mode',
    options: {}
  },
  'alarm_generic.car_connected': {
    value: false,
    lastUpdated: 2026-04-14T13:03:10.751Z,
    type: 'boolean',
    getable: true,
    setable: false,
    title: 'Car connected',
    desc: 'Generic alarm',
    units: null,
    id: 'alarm_generic.car_connected',
    options: {
      title: [Object],
      insightsTitleTrue: [Object],
      insightsTitleFalse: [Object]
    }
  },
  available_installation_current: {
    value: 16,
    lastUpdated: 2026-04-14T20:28:30.547Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Current limit',
    desc: 'Set the amount of current available for an installation of chargers.',
    units: 'A',
    decimals: 0,
    min: 0,
    max: 40,
    step: 1,
    iconObj: {
      id: '90dc388b015d75b858870078c06f8936',
      url: '/icon/90dc388b015d75b858870078c06f8936/icon.svg'
    },
    chartType: 'stepLine',
    id: 'available_installation_current',
    options: { title: [Object] }
  },
  'measure_current.phase1': {
    value: 0.02,
    lastUpdated: 2026-04-14T13:03:10.427Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Current L1',
    desc: 'Electric current (A)',
    units: 'A',
    decimals: 2,
    chartType: 'stepLine',
    id: 'measure_current.phase1',
    options: { title: [Object] }
  },
  'measure_current.phase2': {
    value: 0.02,
    lastUpdated: 2026-04-14T13:03:10.448Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Current L2',
    desc: 'Electric current (A)',
    units: 'A',
    decimals: 2,
    chartType: 'stepLine',
    id: 'measure_current.phase2',
    options: { title: [Object] }
  },
  'measure_current.phase3': {
    value: 0.03,
    lastUpdated: 2026-04-14T13:03:10.550Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Current L3',
    desc: 'Electric current (A)',
    units: 'A',
    decimals: 2,
    chartType: 'stepLine',
    id: 'measure_current.phase3',
    options: { title: [Object] }
  },
  'measure_voltage.phase1': {
    value: 2.76,
    lastUpdated: 2026-04-14T13:03:10.180Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Voltage L1',
    desc: 'Voltage (V)',
    units: 'V',
    decimals: 2,
    chartType: 'stepLine',
    id: 'measure_voltage.phase1',
    options: { title: [Object] }
  },
  'measure_voltage.phase2': {
    value: 0.36,
    lastUpdated: 2026-04-14T13:03:10.192Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Voltage L2',
    desc: 'Voltage (V)',
    units: 'V',
    decimals: 2,
    chartType: 'stepLine',
    id: 'measure_voltage.phase2',
    options: { title: [Object] }
  },
  'measure_voltage.phase3': {
    value: 0.61,
    lastUpdated: 2026-04-14T13:03:10.204Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Voltage L3',
    desc: 'Voltage (V)',
    units: 'V',
    decimals: 2,
    chartType: 'stepLine',
    id: 'measure_voltage.phase3',
    options: { title: [Object] }
  },
  measure_humidity: {
    value: 24.25,
    lastUpdated: 2026-04-15T04:15:00.742Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Humidity',
    desc: 'Humidity in percent (%)',
    units: '%',
    decimals: 2,
    chartType: 'spline',
    id: 'measure_humidity',
    options: {}
  },
  measure_temperature: {
    value: 23.2,
    lastUpdated: 2026-04-15T04:15:00.736Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Temperature',
    desc: 'Temperature in degrees Celsius (°C)',
    units: '°C',
    decimals: 1,
    chartType: 'spline',
    id: 'measure_temperature',
    options: {}
  },
  'meter_power.signed_meter_value': {
    value: 0.08,
    lastUpdated: 2026-04-14T13:03:10.725Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Signed meter value',
    desc: 'Energy usage in kilowatt-hour (kWh)',
    units: 'kWh',
    decimals: 2,
    chartType: 'spline',
    id: 'meter_power.signed_meter_value',
    options: { title: [Object], uiComponent: 'none' }
  },
  measure_signal_strength: {
    value: -72,
    lastUpdated: 2026-04-14T23:57:00.918Z,
    type: 'number',
    getable: true,
    setable: false,
    title: 'Signal strength',
    desc: 'The signal strength in decibels.',
    units: '%',
    decimals: 2,
    chartType: 'spline',
    id: 'measure_signal_strength',
    options: { title: [Object], units: '%' }
  },
  communication_method: {
    value: null,
    lastUpdated: null,
    type: 'string',
    getable: true,
    setable: false,
    title: 'Communication method',
    desc: 'Communication technology, LTE or Wifi',
    units: null,
    iconObj: {
      id: '90dc388b015d75b858870078c06f8936',
      url: '/icon/90dc388b015d75b858870078c06f8936/icon.svg'
    },
    id: 'communication_method',
    options: {}
  },
  charging_mode: {
    value: '0',
    lastUpdated: 2026-04-14T13:03:10.043Z,
    type: 'enum',
    getable: true,
    setable: true,
    title: 'Charging mode',
    desc: 'Set the charging mode of the charger. Available modes are: Default charging, Scheduled charging, and Automatic charging.',
    units: null,
    values: [ [Object], [Object], [Object] ],
    id: 'charging_mode',
    options: {}
  }
}

Set capability log

[HomeyAPIError: An unknown error has occurred [not_setable]] {
  statusCode: 500,
  description: 'An unknown error has occurred [not_setable]'
}

[TMBom]

The available_installation_current is a reading that the app retrieves from the Zaptec API and therefore it is not settable. In the current version of the app, I think you cannot set the current limit using Homeyscript. You could potentially work around this to let the Homeyscript calculate the current limit and then pass it to an advanced flow that uses a flow card to set the current.

[0ge]

Ok, that makes sense. But is there a technical reason why the phase currents are only available in flows and not in HomeyScript?

[TMBom]

The capability is implemented as a sensor in this app and does not pass any changes back to the charger.

I just discovered that you can also trigger flow cards from Homey Script. The following script works for me:

const response = await Homey.flow.runFlowCardAction({
      uri: 'homey:flowcardaction:homey:device:379f15e0-cb3e-4500-f636-a98e319a9e5b:go2_installation_current_control',
      id: 'homey:device:379f15e0-cb3e-4500-f636-a98e319a9e5b:go2_installation_current_control',
      args: {current1:12,current2:12,current3:12}
    });

console.log(response);

Make sure to replace the device ID with the device ID of your charger. You can find this in the Homey developer portal.