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hems

The hems section configures external control of consumption and feed-in power. This is used e.g. for implementing German §14a EnWG or §9 EEG regulations. For background and setup details, see External Control.

Note

When hems is configured, an "External Limit" circuit (gridcontrol) is automatically created. No manual circuit configuration is required.

SMA Sunny Home Manager & SEMP Protocol

The SMA Sunny Home Manager (SHM) integration is active by default and no longer needs to be configured under hems:. For details and configuration options, see Configuration > Sunny Home Manager.

Required Parameters​

type​

Defines the type of external control.

Possible values:

  • relay: Connection via switch contact
  • eebus: Connection via the EEBus protocol

type: relay​

Connection via a switch contact (e.g. control box). The contact signals whether a power limitation is active.

hems:
  type: relay
  maxPower: 8400 # Total power limit when signal is active (in watts)
  limit:
    source: gpio
    function: read
    pin: 17

Parameters​

maxPower​

Total power limit in watts that is applied when the signal is active.

limit​

Plugin configuration for reading the switch contact. Expected return value: true/1 = limited, false/0 = normal.

passthrough​

Optional plugin configuration for passing the limitation signal through to an external system.

interval​

Polling interval for the switch contact. Default: 10s.

For more examples of different connections (GPIO, MQTT, HTTP), see External Control.

type: eebus​

Connection via the EEBus protocol. The control box automatically transmits the power limit.

hems:
  type: eebus
  ski: "1234-5678-90AB-CDEF" # SKI of the control box

Parameters​

ski​

SKI (Subject Key Identifier) of the control box. Required for pairing.

Advanced Limits​

The following optional parameters can be set for EEBus communication:

  • contractualConsumptionNominalMax: Contractual maximum consumption power (in watts)
  • failsafeConsumptionActivePowerLimit: Failsafe limit for consumption power (in watts)
  • failsafeProductionActivePowerLimit: Failsafe limit for feed-in power (in watts)
  • failsafeDurationMinimum: Minimum failsafe duration (e.g. 2h)

passthrough​

Optional plugin configuration for passing the limitation signal through to an external system.

interval​

Polling interval. Default: 10s.

For setup and pairing details, see External Control.