AION EMS Zeus Smart Control takes the next step beyond monitoring.
Instead of only showing where your energy is going, Zeus can use live energy conditions, available solar surplus, device measurements, temperatures and configured safety limits to intelligently control supported devices.
Smart Control is designed around one important principle:
Zeus observes first. Control is only enabled when you explicitly allow it.
Currently, Smart Control has been real-world validated with the my-PV AC ELWA 2. Additional controllable devices should only be documented as supported after their control path has been properly tested.
Before You Start
Do not enable Smart Control until the basic Zeus energy system has been verified.
Before continuing, make sure:
- Grid import/export is correct
- Solar production is correct
- House consumption is correct
- The controlled device reports the correct Power
- Required temperature sensors are correct
- The device operates normally without Zeus
- The Verify Your System steps have been completed
Smart Control should never be used to compensate for incorrect mappings.
Observe Only vs Zeus Permitted
A newly registered controllable device starts safely.
Zeus distinguishes between:
Observe Only
Zeus can monitor and analyze the device, but it cannot control it.
This is the recommended state while configuring and verifying a new device.
Zeus Permitted
The user has explicitly granted Zeus permission to control the device.
Permission does not mean Zeus should blindly switch or change the device. The configured control logic, operating limits and safety conditions must still allow the action.
You decide which devices Zeus is allowed to control.
Step 1 — Open Smart Control & Safety
Open:
AION EMS Zeus → Device Manager
Find the device you want Zeus to control and choose:
Edit Device
Open:
Smart Control & Safety
For a supported Water Heater such as ELWA, Zeus will provide the control profile and required configuration fields.
Step 2 — Select the Control Profile
Choose the appropriate Smart Control profile for the device.
For the currently validated ELWA implementation, select:
my-PV ELWA
The profile tells Zeus which control method and safety model apply to this device.
Do not select a control profile simply because another device appears similar.
Only use profiles intended for the actual hardware.
Step 3 — Mark the Device as Controllable
Enable:
Mark this device as controllable
This tells Zeus that the device has a supported control path.
This alone does not give Zeus permission to execute commands.
Step 4 — Grant Zeus Control Permission
After verifying the configuration, enable:
Grant Zeus control permission
The device can now move from:
Observe Only
to:
Zeus permitted
This is an explicit safety boundary.
If you do not grant permission, Zeus continues monitoring the device without controlling it.
ELWA Smart Control
The my-PV AC ELWA 2 can act as a flexible solar-surplus load.
Instead of exporting all available surplus electricity to the grid, Zeus can direct part of that energy toward domestic hot-water production.
The objective is not simply to turn the heater on whenever solar is available.
Zeus considers:
Available surplus
Grid reserve
Minimum useful power
Maximum allowed power
Boiler temperature
Heating-element temperature
Backup requirements
Safety limits
before deciding what the device should do.
Step 5 — Configure the Actuator
Zeus needs a validated method for sending commands to the controlled device.
For ELWA, this can use the configured Modbus target.
Depending on your Home Assistant configuration, this includes information such as:
Modbus Hub
Unit / Slave ID
Register Address
These values must match your actual ELWA/Home Assistant Modbus configuration.
Do not copy Modbus addresses from another installation unless you have confirmed that your device uses the same configuration.
An incorrect Modbus target can result in commands being sent to the wrong register.
Step 6 — Configure Power Limits
Set the operating range Zeus is allowed to request.
For example:
Minimum Power
The lowest useful operating power for the controlled device.
Maximum Power
The highest power Zeus is allowed to request.
Zeus must keep requested power inside these configured limits.
The maximum Smart Control value does not need to equal the absolute hardware maximum. You may deliberately configure a lower limit.
Step 7 — Configure Solar Control
Solar Control determines when available surplus is sufficient to operate the device.
Important settings can include:
Solar Start Threshold
The amount of available surplus required before Zeus considers starting the device.
This prevents the heater from repeatedly starting for very small or unstable amounts of surplus.
Grid Export Reserve
Zeus can deliberately leave part of the surplus available for export instead of consuming everything.
For example:
Available surplus: 2,000 W
Configured reserve: 400 W
Zeus should not request the entire 2,000 W for the controlled device.
The reserve provides headroom for changing household loads and helps reduce unnecessary grid import caused by rapid fluctuations.
Step 8 — Configure Boiler Temperature Limits
Temperature limits prevent Zeus from continuing solar heating when the hot-water tank is already sufficiently warm.
A typical configuration uses:
Stop Temperature
When the boiler reaches this temperature, Zeus stops requesting additional solar heating.
Restart Temperature
Heating is allowed again after the boiler temperature falls below this value.
The difference between the two temperatures prevents unnecessary rapid switching.
Choose temperature limits appropriate for your own hot-water system.
Step 9 — Configure Element Temperature Protection
If the device provides a heating-element temperature sensor, Zeus can use it as additional safety evidence.
Useful limits include:
Taper Temperature
As the heating element approaches a high temperature, Zeus can reduce requested power.
This allows the system to approach the final temperature more gently.
Hard Stop Temperature
At this temperature, Zeus stops requesting heating.
This is an additional control layer and does not replace the device manufacturer’s internal safety protections.
Step 10 — Configure Grid Backup
Solar surplus is not always available.
If desired, Zeus can allow limited grid-powered water heating when the boiler becomes too cold.
For example:
Backup Start Temperature
Below this temperature, grid heating may be allowed.
Backup Stop Temperature
Once the minimum comfort temperature has been restored, backup heating stops.
This creates a simple principle:
Use surplus solar whenever possible. Use the grid only when hot-water comfort requires it.
Grid Backup is optional.
If you do not want Zeus to use grid electricity for water heating, keep the corresponding control behavior disabled.
Step 11 — Active Command Keepalive
Some controllable devices require the requested operating value to be refreshed periodically.
Zeus can maintain an active command using a configured Keepalive interval.
This helps ensure that the device continues receiving the intended operating target while Smart Control remains active.
The keepalive does not bypass the normal Zeus safety logic.
If conditions change — for example the boiler reaches its stop temperature — Zeus should change or stop the command accordingly.
How Zeus Makes a Decision
A simplified Smart Control decision can look like this:
Is Zeus permitted to control the device?
↓ YES
Are the required measurements available?
↓ YES
Is the device inside its configured safety limits?
↓ YES
Is useful solar surplus available?
↓ YES
Calculate safe requested power
↓
Apply configured reserve and power limits
↓
Send the command
At every stage, a failed safety or permission condition can prevent execution.
Example — Solar Surplus
Imagine:
Solar production: 7.0 kW
House demand: 3.5 kW
Available surplus: 3.5 kW
The ELWA Smart Control configuration allows:
Maximum ELWA power: 2.0 kW
Grid reserve: 400 W
Zeus can request up to the configured ELWA limit while still maintaining the required reserve.
If household demand suddenly increases, Zeus can reduce the ELWA request accordingly.
This is why Smart Control uses live energy conditions, not a fixed timer.
Example — Boiler Already Hot
Imagine:
Solar surplus: 3.0 kW
Boiler temperature: at the configured stop temperature
Even though plenty of solar energy is available, Zeus should not continue heating simply because surplus exists.
The temperature limit takes priority.
Available energy does not override safety and operating limits.
Example — No Solar and Cold Water
Imagine:
Solar surplus: 0 W
Boiler temperature: below the configured Backup Start temperature
If Grid Backup is enabled, Zeus may temporarily use grid energy to restore the configured minimum hot-water temperature.
Once the Backup Stop temperature is reached, grid heating stops.
The purpose is to maintain minimum comfort without turning Grid Backup into normal unrestricted electric heating.
Control Ownership
A device should have a clear control owner.
Before granting Zeus control, check whether another Home Assistant automation, script or external controller is already sending commands to the same device.
Two independent controllers attempting to manage the same power target can conflict.
If Zeus becomes the active controller for a device, avoid running another automation that continuously writes competing commands to the same actuator.
Manufacturer Safety Remains Primary
Zeus Smart Control is an additional energy-management layer.
It does not replace:
- Manufacturer safety systems
- Temperature protection
- Electrical protection
- Device firmware limits
- Correct installation
- Required professional safety equipment
Never disable manufacturer safety mechanisms in order to allow Zeus to control a device.
Verify Smart Control
After enabling Smart Control, watch the system during real operation.
Compare:
Available surplus
Requested device power
Actual device power
Grid import/export
Boiler temperature
Element temperature
When Zeus requests power, the real device measurement should respond accordingly.
If Zeus requests approximately:
1,200 W
the device should eventually report approximately:
1,200 W
allowing for normal control and measurement delays.
Watch the Grid
One of the easiest ways to validate surplus control is to watch the Grid measurement.
When Zeus increases a flexible load, it should not unnecessarily push the home into significant grid import if the control objective is solar-surplus operation.
Small temporary changes are normal because sensors and devices do not update simultaneously.
Persistent unexpected grid import should be investigated.
Emergency Stop / Disable Control
You should always know how to return a device to monitoring-only operation.
If you do not want Zeus to control a device:
Remove/revoke Zeus control permission
The device should return to:
Observe Only
You can then investigate the configuration without Zeus actively controlling the hardware.
Start Conservatively
For a first Smart Control setup, use conservative power and temperature limits.
Watch several real operating cycles before increasing the permitted operating range.
A good Smart Control configuration is not the one that consumes the maximum possible surplus at every second.
It is the one that operates predictably, safely and without fighting the rest of the home’s energy system.
Smart Control Is Ready
Once you have confirmed that:
- Zeus detects surplus correctly
- requested power respects the configured limits
- the real device follows the requested power
- temperature limits stop/restart heating correctly
- Grid Backup behaves as intended
- control permission can be revoked
- no competing automation is controlling the same device
your Smart Control setup is ready for normal use.
For now, the public guide should present my-PV AC ELWA 2 as the validated Smart Control implementation. As we validate additional controllable hardware, we can add dedicated device guides rather than implying that every registered Zeus device can already be controlled.
Observe first. Verify the evidence. Grant control deliberately. Let Zeus optimize within the limits you define.