Fronius Ohmpilot Operating Instructions

1. Safety rules

1. Safety rules

• Serious or fatal injury to the operator or third parties
• Damage to the device and other material assets belonging to the operating company

• Be suitably qualified
• Have knowledge of and experience in dealing with electrical installations
• Read and follow these Operating Instructions carefully

In addition to the Operating Instructions, all applicable local rules and regulations regarding accident prevention and environmental protection must also be followed.

• Must be kept in a legible state
• Must not be damaged
• Must not be removed
• Must not be covered, pasted or painted over

• Serious or fatal injury to the operator or third parties
• Damage to the device and other material assets belonging to the operating company

Any safety devices that are not fully functional must be repaired by an authorized specialist before the device is switched on.

Never bypass or disable protection devices.

For the location of the safety and danger notices on the device, refer to the chapter headed "Warning notices on the device" in the Operating Instructions for your device.

Faults that could compromise safety must be remedied before switching on the device.

1. Safety rules

Operation or storage of the device outside the stipulated area will be deemed as not in accordance with the intended purpose. The manufacturer accepts no liability for any damage resulting from improper use.

1. Safety rules

The servicing information contained in these operating instructions is intended only for the use of qualified service engineers. An electric shock can be fatal. Do not carry out any actions other than those described in the documentation. This also applies to qualified personnel.

All cables and leads must be secured, undamaged, insulated and adequately dimensioned. Loose connections, scorched, damaged or inadequately dimensioned cables and leads must be immediately repaired by authorised personnel.

Maintenance and repair work must only be carried out by an authorised specialist.

It is impossible to guarantee that bought-in parts are designed and manufactured to meet the demands made on them, or that they satisfy safety requirements. Use only original spare parts (also applies to standard parts).

Do not carry out any alterations, installations, or modifications to the device without first obtaining the manufacturer's permission.

Components that are not in perfect condition must be changed immediately.

1. Safety rules

In certain cases, even though a device complies with the standard limit values for emissions, it may affect the application area for which it was designed (e.g., when there is equipment that is susceptible to interference at the same location, or if the site where the device is installed is close to either radio or television receivers). If this is the case, then the operator is obliged to take action to rectify the situation.

1. Safety rules

• backing up any changes made to the factory settings
• saving and retaining personal settings

1. Safety rules

Copyright of these operating instructions remains with the manufacturer.

The text and illustrations are all technically correct at the time of printing. We reserve the right to make changes. The contents of the operating instructions shall not provide the basis for any claims whatsoever on the part of the purchaser. If you have any suggestions for improvement, or can point out any mistakes that you have found in the instructions, we will be most grateful for your comments.

The Fronius Ohmpilot is an addition to the Fronius product portfolio in the field of energy management. The device controls the heating of hot water using surplus energy from a photovoltaic system. Any other use is considered improper.

1. General information

The Fronius Ohmpilot is an addition to the Fronius product portfolio in the field of energy management. The device controls the heating of hot water using surplus energy from a photovoltaic system. Any other use is considered improper.

1. General information
2. General

The Fronius Ohmpilot is an addition to the Fronius product portfolio in the field of energy management. The device controls the heating of hot water using surplus energy from a photovoltaic system. Any other use is considered improper.

1. General information
2. General

• GEN24 inverter
  • Fronius Primo / Symo GEN24
• Fronius SnapINverter
  • Fronius Symo / Galvo / Eco or Primo (from Fronius Datamanager 2.0 software version 3.8.1-x onwards) or Fronius Symo Hybrid (from Fronius Hybridmanager software version V1.8.1.x onwards)
• Fronius Smart Meter
• Fronius Ohmpilot
• Resistive load (e.g. boiler with heating element)

1. General information
2. General

To operate the Ohmpilot, a Fronius Smart Meter is required to measure the surplus energy. On the user interface of the inverter, it is necessary to set whether the Fronius Smart Meter is installed at the feed-in point or in the consumption branch.

1. General information
2. General

The Ohmpilot uses pulse width modulation to regulate the surplus power from the photovoltaic system for one phase. With one phase, it is possible to control a heating element with a continuously variable output of up to 3 kW for example. The Ohmpilot has two additional outputs for switching further phases. This means that heating elements with an output of 300 W to 9 kW can be controlled.

For a heating element with 9 kW output, the surplus power of 0 - 3 kW is controlled in phase 1. If more power is available, the Ohmpilot switches to phase 2. Phase 1 can therefore be continuously adjusted between 3 and 6 kW. If the available power is > 6 kW, the Ohmpilot adds phase 3. Phase 1 is again continuously adjusted between 6 and 9 kW

Other resistive loads such as infra-red heaters and towel dryers can also be controlled.

1. General information
2. General

1. General information
2. General

Safety symbols and warnings are located on the left-hand side of the Ohmpilot. These warning notices and safety symbols must not be removed or painted over. They warn against incorrect operation, as this may result in serious injury and damage.

Safety symbols:
	Danger of serious injury and damage due to incorrect operation
	Do not use the functions described here until you have fully read and understood the following documents: These Operating Instructions All the Operating Instructions for the system components, especially the safety rules
	Dangerous electrical voltage
	Before opening the machine, wait for the capacitors to discharge!
	Hot surface

Text of the warning notices:

WARNING!
An electric shock can be fatal. Before opening the device, it must be disconnected at the input and output. Wait for the capacitors to discharge (15 seconds).

WARNING!
The device must not be covered and nothing may be hung over the device or cable.

1. General information

		Function key	1x WPS 2x ACCESS POINT 3x BOOST MODE
		Press 1x	WPS (Wi-Fi Protected Setup) opens for 2 minutes or until successful pairing with the router. Pressing the WPS button on the router sends the WLAN password to the Ohmpilot.
		Press 2x	WLAN access point is activated for 30 minutes so that settings can be implemented on the Ohmpilot via the Fronius Solar.web app.
		Press 3x	Boost mode - dimmer level is activated at 100% for 4 hours, switching takes place through phases 2 and 3. This may result in electricity being sourced from the grid.
		Press again	Ohmpilot is returned to the standard operating mode; boost mode, access point or WPS are deactivated.
		Press for 7 seconds	Ohmpilot restarts
	Heater indication	Unlit	No power supply to the Ohmpilot.
		Flashing green (permanently)	The faster the flashing frequency, the greater the heat output. The LED flashes slowly at 0 W heat output and quickly at full output.
		Flashing green (twice)	The heating element output is being measured. The Ohmpilot recognises whether a 1-phase or 3-phase heating element is connected.
		Lights up green	Minimum temperature undershot or Legionella prevention system active (full heat output).
	LAN / WLAN connection indicator	Unlit	No connection
		Flashing blue (once)	WPS (Wi-Fi Protected Setup) open
		Flashing blue (twice)	WLAN access point open
		Lights steady blue	Connection with network
	Error indication	Unlit	No error
		Flashing red (once)	No connection to the inverter
		Flashing red (twice)	Temperature measurement faulty
		Flashing red (three times)	Heating element faulty
		Flashing red (four times)	Ohmpilot faulty
		Flashing red (five times)	Minimum temperature not reached
		A detailed description of the error is provided in Fronius Solar.web.

1. General information
2. Control elements and connections

		Function key	1x WPS 2x ACCESS POINT 3x BOOST MODE
		Press 1x	WPS (Wi-Fi Protected Setup) opens for 2 minutes or until successful pairing with the router. Pressing the WPS button on the router sends the WLAN password to the Ohmpilot.
		Press 2x	WLAN access point is activated for 30 minutes so that settings can be implemented on the Ohmpilot via the Fronius Solar.web app.
		Press 3x	Boost mode - dimmer level is activated at 100% for 4 hours, switching takes place through phases 2 and 3. This may result in electricity being sourced from the grid.
		Press again	Ohmpilot is returned to the standard operating mode; boost mode, access point or WPS are deactivated.
		Press for 7 seconds	Ohmpilot restarts
	Heater indication	Unlit	No power supply to the Ohmpilot.
		Flashing green (permanently)	The faster the flashing frequency, the greater the heat output. The LED flashes slowly at 0 W heat output and quickly at full output.
		Flashing green (twice)	The heating element output is being measured. The Ohmpilot recognises whether a 1-phase or 3-phase heating element is connected.
		Lights up green	Minimum temperature undershot or Legionella prevention system active (full heat output).
	LAN / WLAN connection indicator	Unlit	No connection
		Flashing blue (once)	WPS (Wi-Fi Protected Setup) open
		Flashing blue (twice)	WLAN access point open
		Lights steady blue	Connection with network
	Error indication	Unlit	No error
		Flashing red (once)	No connection to the inverter
		Flashing red (twice)	Temperature measurement faulty
		Flashing red (three times)	Heating element faulty
		Flashing red (four times)	Ohmpilot faulty
		Flashing red (five times)	Minimum temperature not reached
		A detailed description of the error is provided in Fronius Solar.web.

1. General information
2. Control elements and connections

1. General information

Controlled in a continuously variable manner from 0.3 to 3 kW

• Resistive load (no electronic temperature limiters, fans, etc.)

1. General information
2. Selection of heater

Controlled in a continuously variable manner from 0.3 to 3 kW

• Resistive load (no electronic temperature limiters, fans, etc.)

1. General information
2. Selection of heater

Controlled in a continuously variable manner from 0.3 to 9 kW.

• Equal load distribution on all 3 phases (e.g. 3 x 3 kW).
• If a mechanical temperature switch is being used, it must switch all 3 phases simultaneously.
• Purely resistive load (no electronic temperature limiters, fans, etc.)
• Neutral conductor must be connected

Temperature limitation
A mechanical temperature switch simplifies commissioning and use. If no mechanical temperature switch is available, a temperature sensor can also be connected to the Ohmpilot. This limits the maximum temperature (see chapter "Temperature limitation" on page).

1. General information
2. Selection of heater

500 l boiler, heater is fitted at the very bottom of the boiler,
temperature spread 45 - 60 °C = 15 °C
4.5 kW heater

Possible stored energy = 500 l (storage tank capacity) x 1.16 Wh (energy requirement per litre) x 15 °C (temperature spread) = 8.7 kWh. If the heater at full power (4.5 kW), heating up takes approximately 2 hours.

For optimum utilisation of the surplus power and rapid reheating of the hot water, adjust the output of the heating system to the output of the photovoltaic system, e.g. 5 kWp system output => 4.5 kW heating

Please note the following criteria when choosing a location for the Ohmpilot:

Install only on a solid surface.
		Max. ambient temperatures: 0 °C / +40 °C
		Relative humidity: 0 - 99%
		The airflow within the Ohmpilot is from the bottom to the top.
If the Ohmpilot is installed in an enclosed space, forced-air ventilation must be provided to ensure adequate heat dissipation.

1. Installation and commissioning

Please note the following criteria when choosing a location for the Ohmpilot:

Install only on a solid surface.
		Max. ambient temperatures: 0 °C / +40 °C
		Relative humidity: 0 - 99%
		The airflow within the Ohmpilot is from the bottom to the top.
If the Ohmpilot is installed in an enclosed space, forced-air ventilation must be provided to ensure adequate heat dissipation.

1. Installation and commissioning
2. Choice of location and installation position

Please note the following criteria when choosing a location for the Ohmpilot:

Install only on a solid surface.
		Max. ambient temperatures: 0 °C / +40 °C
		Relative humidity: 0 - 99%
		The airflow within the Ohmpilot is from the bottom to the top.
If the Ohmpilot is installed in an enclosed space, forced-air ventilation must be provided to ensure adequate heat dissipation.

1. Installation and commissioning
2. Choice of location and installation position

		The Ohmpilot is suitable for indoor installation. The housing satisfies protection class IP 54 and is protected against splashing water on all sides.
		In order to minimise heating up of the Ohmpilot, do not expose it to direct sunlight. Install the Ohmpilot in a protected position. The Ohmpilot must only be installed and operated at an ambient temperature of 0-40 °C.
		IMPORTANT! The Ohmpilot must not be installed or used at altitudes above 2000 m.
		Do not install the Ohmpilot: In areas where ammonia, corrosive vapours, acids or salts are present (e.g. fertiliser stores, ventilation openings from cattle sheds, chemical plants, tanneries, etc.)
		Do not install the Ohmpilot in: Places where there is an increased risk of damage from farm animals (horses, cattle, sheep, pigs, etc.) Stables or adjoining areas Storage areas for hay, straw, chaff, animal feed, fertilisers, etc.
		Do not install the Ohmpilot in rooms or environments where there is a lot of dust. All Ohmpilot units are designed to be dust-tight. However, in areas with a heavy build-up of dust, the thermal efficiency may still be impaired by dust forming on the cooling surfaces. Regular cleaning is necessary in such situations.
		Do not install the Ohmpilot in: Greenhouses Storage or processing areas for fruit, vegetables or viticulture products Areas used in the preparation of grain, green fodder or animal feeds

1. Installation and commissioning
2. Choice of location and installation position

The Ohmpilot must be installed level, with the connections facing downwards, on a vertical wall. All inclined and horizontal installation positions are prohibited.

1. Installation and commissioning

IMPORTANT! The IP 54 protection class only applies if the cover is firmly screwed to the back.

1. Installation and commissioning
2. Wall mounting

IMPORTANT! The IP 54 protection class only applies if the cover is firmly screwed to the back.

1. Installation and commissioning
2. Wall mounting

IMPORTANT! Different fixings may be required to fit the Ohmpilot, depending on the type of surface. The fixings are not included in the scope of supply. The installer is responsible for selecting the right type of fixing. The underlying surface must be load-bearing.

To install the Ohmpilot in masonry, Fronius recommends the use of steel screws with a diameter of 4 - 6 mm.

1. Installation and commissioning
2. Wall mounting

1

Undo the 4 screws and remove the housing cover.

2

Mark drill holes, drill and insert wall plugs

3Attach the Ohmpilot to the wall with 4 screws

1. Installation and commissioning

Stripping lengths of terminals for power stage set (L1, L2, etc.) and terminals for data communication area (D+, D-, PT1000)

1. Installation and commissioning
2. Installation

Stripping lengths of terminals for power stage set (L1, L2, etc.) and terminals for data communication area (D+, D-, PT1000)

1. Installation and commissioning
2. Installation

IMPORTANT! Electrical connection work must be carried out by a specialist.

1. Installation and commissioning

IMPORTANT! Plug & Play - no further settings are required for this application after successful connection to the inverter.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot. Surplus energy is consumed using the heating element in a continuously variable manner.

If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can ensure the minimum temperature. To do this, a temperature sensor must be connected so that the Ohmpilot can measure the temperature. This may result in electricity being sourced from the grid.

The maximum temperature must be set on the heating element thermostat. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

1. Installation and commissioning
2. 1-phase heating element up to 3 kW

IMPORTANT! Plug & Play - no further settings are required for this application after successful connection to the inverter.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot. Surplus energy is consumed using the heating element in a continuously variable manner.

If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can ensure the minimum temperature. To do this, a temperature sensor must be connected so that the Ohmpilot can measure the temperature. This may result in electricity being sourced from the grid.

The maximum temperature must be set on the heating element thermostat. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

1. Installation and commissioning

IMPORTANT! Plug & Play - no further settings are required for this application after successful connection to the inverter.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot. This means that the surplus energy is consumed in a continuously variable manner by the heating element.
Depending on the surplus power, the individual phases are switched on or off and the remaining power is consumed at L1. As a result, the heating element output is divided by three.

If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can ensure the minimum temperature. To do this, a temperature sensor must be connected so that the Ohmpilot can measure the temperature. This may result in electricity being sourced from the grid.

The maximum temperature must be set on the heating element thermostat. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

IMPORTANT! A neutral conductor must be connected to the heating element!

1. Installation and commissioning
2. 3-phase heating element 900 W up to 9 kW

IMPORTANT! Plug & Play - no further settings are required for this application after successful connection to the inverter.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot. This means that the surplus energy is consumed in a continuously variable manner by the heating element.
Depending on the surplus power, the individual phases are switched on or off and the remaining power is consumed at L1. As a result, the heating element output is divided by three.

If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can ensure the minimum temperature. To do this, a temperature sensor must be connected so that the Ohmpilot can measure the temperature. This may result in electricity being sourced from the grid.

The maximum temperature must be set on the heating element thermostat. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

IMPORTANT! A neutral conductor must be connected to the heating element!

1. Installation and commissioning

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot and by targeted switching on of the heat pump.

For activation, the heat pump must have a control input (SG Ready or approval from grid operator). The heat pump can be switched from normal operation to boost mode by activating input 2 of the heat pump with the relay. The heat pump can also be switched from grid operator-blocked operation to normal operation by activating input 1 of the heat pump with the relay. Information on the compatibility of the heat pump with this control unit can be found in the operating instructions for the respective device.

Relatively small surpluses are consumed by the heating element in a continuously variable manner. The heat pump should be activated above a certain surplus output due to the higher efficiency. The average COP (coefficient of performance) for water heating up to 53 °C is 2.5. This means that 1 kW of electrical energy is converted into 2.5 kW of thermal energy.

The optimum switching times depend on the following factors:

• Heat pump COP. The higher the temperature to which the hot water is heated, the lower the COP.
• The electrical heat pump output.
• Feed-in tariff and the costs for purchasing energy.
• Reduction of the heat pump's start-up cycles = increase in service life of the heat pump.
• Thermal losses from the heat pump and the pipes.

If no temperature sensor is fitted, the heat pump must ensure the minimum temperature is met. As an alternative, the Ohmpilot can also ensure the minimum temperature by activating the heat pump. This may result in electricity being sourced from the grid. The maximum temperature must be set on the heating element thermostat and on the heat pump. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

This function can also be combined with a 3-phase heating element.

1. Installation and commissioning
2. 1-phase heating element up to 3 kW with heat pump control

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot and by targeted switching on of the heat pump.

For activation, the heat pump must have a control input (SG Ready or approval from grid operator). The heat pump can be switched from normal operation to boost mode by activating input 2 of the heat pump with the relay. The heat pump can also be switched from grid operator-blocked operation to normal operation by activating input 1 of the heat pump with the relay. Information on the compatibility of the heat pump with this control unit can be found in the operating instructions for the respective device.

Relatively small surpluses are consumed by the heating element in a continuously variable manner. The heat pump should be activated above a certain surplus output due to the higher efficiency. The average COP (coefficient of performance) for water heating up to 53 °C is 2.5. This means that 1 kW of electrical energy is converted into 2.5 kW of thermal energy.

The optimum switching times depend on the following factors:

• Heat pump COP. The higher the temperature to which the hot water is heated, the lower the COP.
• The electrical heat pump output.
• Feed-in tariff and the costs for purchasing energy.
• Reduction of the heat pump's start-up cycles = increase in service life of the heat pump.
• Thermal losses from the heat pump and the pipes.

If no temperature sensor is fitted, the heat pump must ensure the minimum temperature is met. As an alternative, the Ohmpilot can also ensure the minimum temperature by activating the heat pump. This may result in electricity being sourced from the grid. The maximum temperature must be set on the heating element thermostat and on the heat pump. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

This function can also be combined with a 3-phase heating element.

1. Installation and commissioning
2. 1-phase heating element up to 3 kW with heat pump control

General settings, symbolic representation

Example 1: If you have selected "Consume" under the switch-off threshold and a power of 500 W has been entered, the heat pump will be switched off as soon as the power being drawn from the grid exceeds 500 W.

Example 2: If you have selected "Feed-in" under the switch-off threshold and entered a power of 500 W, the heat pump will be switched off as soon as the power being fed in is less than 500 W.

1. Installation and commissioning

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot. Surplus energy is consumed using the heating element in a continuously variable manner.

The temperature is measured by the Ohmpilot. If the temperature falls below the minimum, then an external source (e.g. gas-fired heating) will be activated until the minimum temperature is reached again, so that the Ohmpilot only uses surplus energy and does not draw any energy from the grid.

The maximum temperature must be set on the heating element thermostat. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

The heating element is used for the Legionella prevention program.

This function can also be combined with a 3-phase heating element.

1. Installation and commissioning
2. 1-phase heating element up to 3 kW and external source

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot. Surplus energy is consumed using the heating element in a continuously variable manner.

The temperature is measured by the Ohmpilot. If the temperature falls below the minimum, then an external source (e.g. gas-fired heating) will be activated until the minimum temperature is reached again, so that the Ohmpilot only uses surplus energy and does not draw any energy from the grid.

The maximum temperature must be set on the heating element thermostat. If the heating element does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see "Optional settings" section Optional settings on page (→)).

The heating element is used for the Legionella prevention program.

This function can also be combined with a 3-phase heating element.

1. Installation and commissioning
2. 1-phase heating element up to 3 kW and external source

General settings, symbolic representation

1. Installation and commissioning

Many heating systems consist of a boiler and a buffer, whereby the central heating supplies the buffer, and a control system feeds the hot water boiler via a pump. As with thermal photovoltaic systems, the Ohmpilot is also capable of heating the hot water boiler first and then the buffer, so that the maximum amount of photovoltaic surplus energy can be stored.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. This takes place by continuously adjusting the heating element connected to the Ohmpilot.

For this application, two heating elements are installed, with preference being given to activation of the first heating element (5). Only once the maximum temperature in the boiler (3) has been reached is the second heating element activated in a continuously variable manner, so that the remaining energy can, for example, be stored in a buffer.

If no temperature sensor is connected to the Ohmpilot, after 30 minutes the Ohmpilot attempts to output energy via the first heating element once again. If a temperature sensor is present, the system switches back to the first heating element from a temperature difference of 8 °C (to the temperature measured before switching over).

This switching can also be used for layering in a boiler/buffer, so that the maximum temperature is reached in the top part of the boiler using minimal energy and the remaining energy is stored in the lower part of the boiler. By using layering in a storage tank, it is also possible to store significantly more energy, as a minimum temperature is normally maintained in the top part of the boiler. This means that the temperature difference and thus the amount of energy is rather small. In the lower part of the boiler, a high temperature difference of 50 °C, for example, can be used.

Both the first and the second heating element can be 1-phase or 3-phase. For two 3-phase heating elements, see Application example 6. If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can also ensure the minimum temperature. This may result in electricity being sourced from the grid. The maximum temperature must be set on the heating element thermostat. If heating element 1 (5) does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see chapter Optional settings on page (→)). However, heating element 2 (7) must have a thermostat.

1. Installation and commissioning
2. Two heating elements - 3-phase and 1-phase

Many heating systems consist of a boiler and a buffer, whereby the central heating supplies the buffer, and a control system feeds the hot water boiler via a pump. As with thermal photovoltaic systems, the Ohmpilot is also capable of heating the hot water boiler first and then the buffer, so that the maximum amount of photovoltaic surplus energy can be stored.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. This takes place by continuously adjusting the heating element connected to the Ohmpilot.

For this application, two heating elements are installed, with preference being given to activation of the first heating element (5). Only once the maximum temperature in the boiler (3) has been reached is the second heating element activated in a continuously variable manner, so that the remaining energy can, for example, be stored in a buffer.

If no temperature sensor is connected to the Ohmpilot, after 30 minutes the Ohmpilot attempts to output energy via the first heating element once again. If a temperature sensor is present, the system switches back to the first heating element from a temperature difference of 8 °C (to the temperature measured before switching over).

This switching can also be used for layering in a boiler/buffer, so that the maximum temperature is reached in the top part of the boiler using minimal energy and the remaining energy is stored in the lower part of the boiler. By using layering in a storage tank, it is also possible to store significantly more energy, as a minimum temperature is normally maintained in the top part of the boiler. This means that the temperature difference and thus the amount of energy is rather small. In the lower part of the boiler, a high temperature difference of 50 °C, for example, can be used.

Both the first and the second heating element can be 1-phase or 3-phase. For two 3-phase heating elements, see Application example 6. If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can also ensure the minimum temperature. This may result in electricity being sourced from the grid. The maximum temperature must be set on the heating element thermostat. If heating element 1 (5) does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see chapter Optional settings on page (→)). However, heating element 2 (7) must have a thermostat.

1. Installation and commissioning
2. Two heating elements - 3-phase and 1-phase

General settings, symbolic representation

1. Installation and commissioning

Many heating systems consist of a boiler and a buffer, whereby the central heating supplies the buffer, and a control system feeds the hot water boiler via a pump. As with thermal photovoltaic systems, the Ohmpilot is also capable of heating the hot water boiler first and then the buffer, so that the maximum amount of photovoltaic surplus energy can be stored.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot.

For this application, two heating elements are installed, with preference being given to activation of the first heating element (5). Only once the maximum temperature in the boiler (3) has been reached is the second heating element (7) activated in a continuously variable manner, so that the remaining energy can, for example, be stored in a buffer.

If no temperature sensor is connected to the Ohmpilot, after 30 minutes the Ohmpilot attempts to output energy via the first heating element once again. If a temperature sensor is present, the system switches back to the first heating element from a temperature difference of 8 °C (to the temperature measured before switching over).

This switching can also be used for layering in a boiler/buffer, so that the maximum temperature is reached in the top part of the boiler using minimal energy and the remaining energy is stored in the lower part of the boiler. By using layering in a storage tank, it is also possible to store significantly more energy, as a minimum temperature is normally maintained in the top part of the boiler. This means that the temperature difference and therefore the amount of energy is rather small. In the lower part of the boiler, a high temperature difference of 50 °C, for example, can be used.

Switching must be realised by an external contactor. If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can also ensure the minimum temperature. This may result in electricity being sourced from the grid.

The maximum temperature must be set on the heating element thermostat. If heating element 1 (5) does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see chapter Optional settings on page (→)). However, heating element 2 (7) must have a thermostat.

1. Installation and commissioning
2. Two 3-phase heating elements up to 9 kW

Many heating systems consist of a boiler and a buffer, whereby the central heating supplies the buffer, and a control system feeds the hot water boiler via a pump. As with thermal photovoltaic systems, the Ohmpilot is also capable of heating the hot water boiler first and then the buffer, so that the maximum amount of photovoltaic surplus energy can be stored.

The Fronius Smart Meter records the current power at the feed-in point and transfers the data to the inverter. By controlling the Ohmpilot, the inverter adjusts any surplus energy that is available to zero. Specifically, this takes place by continuously adjusting the heating element connected to the Ohmpilot.

For this application, two heating elements are installed, with preference being given to activation of the first heating element (5). Only once the maximum temperature in the boiler (3) has been reached is the second heating element (7) activated in a continuously variable manner, so that the remaining energy can, for example, be stored in a buffer.

If no temperature sensor is connected to the Ohmpilot, after 30 minutes the Ohmpilot attempts to output energy via the first heating element once again. If a temperature sensor is present, the system switches back to the first heating element from a temperature difference of 8 °C (to the temperature measured before switching over).

This switching can also be used for layering in a boiler/buffer, so that the maximum temperature is reached in the top part of the boiler using minimal energy and the remaining energy is stored in the lower part of the boiler. By using layering in a storage tank, it is also possible to store significantly more energy, as a minimum temperature is normally maintained in the top part of the boiler. This means that the temperature difference and therefore the amount of energy is rather small. In the lower part of the boiler, a high temperature difference of 50 °C, for example, can be used.

Switching must be realised by an external contactor. If no temperature sensor is fitted, an external source (e.g. gas-fired heating) must be used to ensure the minimum temperature is met.

As an alternative, the Ohmpilot can also ensure the minimum temperature. This may result in electricity being sourced from the grid.

The maximum temperature must be set on the heating element thermostat. If heating element 1 (5) does not have a thermostat, the Ohmpilot can also carry out this task as an alternative (see chapter Optional settings on page (→)). However, heating element 2 (7) must have a thermostat.

1. Installation and commissioning
2. Two 3-phase heating elements up to 9 kW

General settings, symbolic representation

1. Installation and commissioning

The Ohmpilot can also control a circulating pump in a heating system in parallel to a heating element via the floating contact of the device control. This is possible with all circulating pumps that have an auxiliary relay.

The designation of the floating contact on the Ohmpilot is NC W NO. When the contact is activated, the switching rocker (W) switches from the "normally open" (NO) position to "normally closed" (NC).

In heating mode, this contact is activated and the circulating pump runs as "HEATER 2" in parallel to the heating element, which is operated via the "HEATER 1" output.

To prevent the auxiliary relay of the circulating pump from switching on and off continuously in case of low or fluctuating PV power, the Ohmpilot is equipped with a delay. This has a positive effect on the wear and service life of the relay and the pump.

1. Installation and commissioning
2. 1-phase heating element up to 3 KW / 3-phase heating element and circulation pump

The Ohmpilot can also control a circulating pump in a heating system in parallel to a heating element via the floating contact of the device control. This is possible with all circulating pumps that have an auxiliary relay.

The designation of the floating contact on the Ohmpilot is NC W NO. When the contact is activated, the switching rocker (W) switches from the "normally open" (NO) position to "normally closed" (NC).

In heating mode, this contact is activated and the circulating pump runs as "HEATER 2" in parallel to the heating element, which is operated via the "HEATER 1" output.

To prevent the auxiliary relay of the circulating pump from switching on and off continuously in case of low or fluctuating PV power, the Ohmpilot is equipped with a delay. This has a positive effect on the wear and service life of the relay and the pump.

1. Installation and commissioning
2. 1-phase heating element up to 3 KW / 3-phase heating element and circulation pump

General settings, symbolic representation

1. Installation and commissioning

The data connection is required for communication between the inverter and the Ohmpilot. The inverter mainly sends default values to the Ohmpilot. For some applications, it is necessary to make settings via the Ohmpilot user interface.

There are 3 possible communication channels:

• Modbus RTU (via RS 485)
• LAN (Ethernet)
• WLAN

1. Installation and commissioning
2. Establishing the data connection

The data connection is required for communication between the inverter and the Ohmpilot. The inverter mainly sends default values to the Ohmpilot. For some applications, it is necessary to make settings via the Ohmpilot user interface.

There are 3 possible communication channels:

• Modbus RTU (via RS 485)
• LAN (Ethernet)
• WLAN

1. Installation and commissioning
2. Establishing the data connection

Each inverter with a Fronius Smart Meter automatically connects to the Ohmpilot. If there are several inverters with Fronius Smart Meter in the network, the Ohmpilot must be paired manually on the user interface of the inverter to be paired under "Device Configuration".

Information on how to access the user interface of the inverter can be found in the operating instructions for the respective device.

1. Installation and commissioning
2. Establishing the data connection

DIP switch settings

1. Installation and commissioning
2. Establishing the data connection

As standard, the Ohmpilot obtains its IP address automatically from the DHCP server, meaning that no settings are generally necessary.

The inverter automatically searches for the Ohmpilot, and the search process may take up to 5 minutes. If the red LED is not lit and the green LED is flashing, the Ohmpilot is working correctly.

A static IP address can be assigned to the Ohmpilot via the user interface.

Set Up Network, symbolic representation

To set the IP address manually, the "Static" option must be selected. Then enter the desired IP address.

The Ohmpilot can then be reached at http://ohmpilotL.local or at the fixed IP address assigned.

1. Installation and commissioning
2. Establishing the data connection

There are two options for connecting the Ohmpilot to an existing WLAN network:

Set Up Navigation, symbolic representation

A static IP address can be assigned to the Ohmpilot via the user interface.

The Ohmpilot can then be reached at http://ohmpilotW.local or at the fixed IP address assigned. Alternatively, the Ohmpilot can also be searched on the network using the Fronius Solar.web App.

1. Installation and commissioning

Boost Mode is used to supply the load at the "Heater 1" output with 100% of the available power for a short time. The dimming level is set to 100% over a maximum period of 4 hours; switching through phases L2 and L3 takes place. This may result in electricity being sourced from the grid.

Boost Mode can be activated and deactivated by pressing the function key on the Ohmpilot (see Indications/controls on the device ) or via the user interface.

1. Installation and commissioning
2. Boost Mode

Boost Mode is used to supply the load at the "Heater 1" output with 100% of the available power for a short time. The dimming level is set to 100% over a maximum period of 4 hours; switching through phases L2 and L3 takes place. This may result in electricity being sourced from the grid.

Boost Mode can be activated and deactivated by pressing the function key on the Ohmpilot (see Indications/controls on the device ) or via the user interface.

1. Installation and commissioning
2. Boost Mode

Boost Mode, symbolic representation

1. Installation and commissioning

Status display, symbolic representation

1. Installation and commissioning
2. User interface

Status display, symbolic representation

1. Installation and commissioning

General settings, symbolic representation

1. Installation and commissioning
2. Optional settings

General settings, symbolic representation

1. Installation and commissioning
2. Optional settings

When the Legionella prevention system is activated, the hot water is heated to 60 °C at a set interval.

1. Installation and commissioning
2. Optional settings

This function ensures that the user-specified temperature is not undershot. If there is insufficient surplus current, the external source (if activated) is controlled or power is drawn from the grid to ensure a minimum temperature.

Up to four time periods and minimum temperatures can be defined. For example, higher hot water temperatures are available in the evening. During the day, more potential for the surplus is then possible by selecting a lower minimum temperature.

1. Installation and commissioning
2. Optional settings

If heater 1 does not have a configurable thermostat, this function can be used to limit the temperature.

• Errors are saved in Fronius Datamanager 2.0 and can be sent via Fronius Solar.web.
• Possible error outputs:

1. Appendix

• Errors are saved in Fronius Datamanager 2.0 and can be sent via Fronius Solar.web.
• Possible error outputs:

1. Appendix
2. Status Codes

• Errors are saved in Fronius Datamanager 2.0 and can be sent via Fronius Solar.web.
• Possible error outputs:

1. Appendix

1. Appendix
2. Technical data

1. Appendix

Tests/specifications per EN60730 Section 1 Table 7.2

1. Appendix
2. Tests/specifications

Tests/specifications per EN60730 Section 1 Table 7.2

1. Appendix

Detailed, country-specific warranty conditions are available on the internet
www.fronius.com/solar/garantie

1. Appendix
2. Warranty terms and conditions, and disposal

Detailed, country-specific warranty conditions are available on the internet
www.fronius.com/solar/garantie

1. Appendix
2. Warranty terms and conditions, and disposal

Waste electrical and electronic equipment must be collected separately and recycled in an environmentally responsible manner in accordance with the EU Directive and national law. Used equipment must be returned to the distributor or through a local, authorised collection and disposal system. Correct disposal of the used device promotes sustainable recycling of resources and prevents negative effects on health and the environment.

• Collect separately
• Observe locally valid regulations
• Compress the cardboard box to reduce volume

1. Appendix
2. Warranty terms and conditions, and disposal

CE mark
The devices conform to all the requisite and relevant standards and guidelines that form part of the relevant EU directive, and are therefore permitted to display the CE mark.