Modes of operation Growatt WIT 4-15K-HU - Load First, Battery First, TOU and zero export

Modes of operation Growatt this is where the same installation can make or lose money - not because of the hardware, but because of the configuration. WIT The 4-15K-HU offers eight basic modes and four system strategies, and the differences between them boil down to three questions: who has priority access to solar energy, can the battery feed energy into the grid, and can any energy flow into the grid at all. This article explains the entire chapter 7 of the user manual (rev. 2025-11, pp. 48-56 of the print; editorial translation from the English edition)—from initial startup, through the mode matrix, to TOU strategies and generator operation. Each mode description comes directly from the manual, and we mark the application scenarios as recommendations from practice.

Before you choose a mode: start-up and first settings

The sequence in chapter 7.1 is short, but two things are often omitted. First: the communication address. A single inverter operates at the default address of 1, but when operating in parallel with RS485 hand-in-hand communication, each unit must be assigned a different address in the range of 1-254—leaving two inverters at the default address of 1 is the shortest route to a communication conflict. Second: the time and date. An inverter stored for longer than a month may display an incorrect time, and the manual requires setting it correctly before connecting to the grid. You do this in the application: Control > Set Inverter Time, enter the password in the format "growatt” + date - for example, February 28, 2024, the password is “growatt20240228″. After connecting to the monitoring server, the time synis now protected automatically. If the inverter is started solely from the battery, the battery button must be held down until it fully wakes up.

Threshold	Value	Inverter behavior
Entering standby mode	PV voltage > 150 V	electronics power supply and system self-test
Full engagement	voltage ≥ 165 V	start of work after a positive self-test
Automatic shutdown	PV < 150 V or battery < 40 V	shutdown; the device waits for the conditions to return, drawing minimal energy (priority: PV > grid > battery)
Communication address	1-254, default 1	for parallel - unique address per unit

Modes of operation Growatt WIT 4-15K-HU - comparison matrix

Configuration Core. Operating Modes Growatt For this series, we've compiled all the variants from section 7.2.2 into a matrix. The "scenario" column is our practical recommendation, while the remaining columns are from the manual. A key rule that applies to most modes is that battery power is not fed back into the grid. The exception is Grid First, designed specifically for selling energy from the storage facility.

What to watch out for when reading the matrix: "surplus to grid" assumes that the export limit is disabled everywhere. With the limit enabled in Load First, nothing flows to the grid—neither from PV nor from batteries. This distinction determines net billing, so always consciously configure the mode and export limit as a pair of settings, not separately.

Zero export - how to work Growatt behave without exports?

Modes of operation Growatt The export limit can be linked to in two different ways, and a common mistake is to treat them interchangeably. The manual describes two mechanisms. The first option is "zero export to meter": the export limit is enforced by an external meter (or three CTs) that detects flow towards the grid and regulates generation to cover only the load and battery charging. A meter is mandatory, and the arrow on its housing must point to the inverter—reverse installation is a classic cause of incorrect flow readings. The second option is "zero export to GRID": the inverter outputs no power at all to the GRID port, and the energy from PV and batteries supplies only the primary load via the LOAD port; neither a meter nor CT is required.

Which one to choose? If the building's network is separated and critical loads rely on the LOAD port, the port variant is more robust—it doesn't depend on the meter being properly installed (a practical recommendation). The meter variant, on the other hand, can also power loads downstream of the metering point, so it's chosen wherever physical separation of circuits is impossible. In both cases, the operating modes Growatt they maintain their priorities – only what happens to the surplus changes.

System strategies: TOU, Smart Load, Peak Shaving and AC Couple

Above the basic modes there is a strategy layer - this is where the modes of operation work Growatt meet the tariff and schedule—and here the manual provides a clear hierarchy: demand management (Peak Shaving) takes precedence over the TOU schedule, and TOU takes precedence over parameter settings. In other words, if the settings "conflict" with each other, the one higher in the hierarchy wins—this is where to start diagnosing why the inverter "isn't following" the schedule.

A practical example for TOU in a low-cost night tariff (recommended from practice, price thresholds according to the customer's tariff): a night slot with Battery First and grid charging enabled, a day slot with Load First for self-consumption, and an evening peak slot with Grid First if the customer settles sales from the warehouse. Each slot is a complete set: the mode plus the AC Charging decision – half of the "TOU not working" reports represent the missing second half of this pair.

A separate chapter is AC Couple - connecting a grid inverter to the GEN port, e.g. when expanding an existing installation on-grid about the warehouse. The manual sets four strict conditions: the rated power of the connected inverter cannot exceed the lower value - the PCS power or the battery power; the inverter must be manufactured Growatt; the security certificate number must be identical to the PCS certificate; and the battery must be a lithium battery with communication. These second and third points invalidate the connection WIT-with a different brand inverter - before you promise a retrofit to a customer, check these four items on the list.

DI, DRMS, AC Couple and Micro-grid Contact - Details That Determine Your Reception

The four mechanisms at the end of Chapter 7 are overlooked during quick setup, and any of them can block the installation's reception. The first is a programmable DI contact: when user-defined mode is enabled, the inverter's AC active power and power factor follow the instructions from the digital input, with the user-defined contact and DRMS ​​sharing the same port—only one DI signal is supported at a time. If the operator requires DRMS, the port is occupied and user-defined control is eliminated.

The second mechanism is AC Couple with four hard conditions for the inverter connected to the GEN port: its rated power cannot exceed the lower of the PCS power and the battery power, it must be an inverter manufactured by Growatt, with the same safety certification number as PCS, and the battery in this mode must be a lithium battery with communication. Therefore, adding someone else's grid inverter to the GEN port is not configuration, but a violation of the manufacturer's terms and conditions.

The third is a micro-grid with a generator on the GEN port: during normal grid operation, the system operates on the grid, but in the event of a power outage, it switches to island mode, and the generator starts automatically when the battery SOC drops below the start threshold and disconnects when the stop threshold is exceeded. The fourth organizes all operating modes. Growatt into one hierarchy: demand side management takes precedence over TOU, and TOU takes precedence over parameter settings - when the inverter behavior "doesn't match" the setting, it is almost always overwritten by the layer above.

The practical consequence of this hierarchy is that the modes of operation Growatt Configuration is done from the top down: first, decide whether the facility uses demand-side management or TOU, and only then tune the basic mode parameters. The reverse order ends with hours of searching for "why Battery First isn't working," which simply overrides the tariff schedule at certain times. In practice: upon delivery, show the customer in the app which layer is currently active—a single hierarchy demonstration eliminates most reports of "arbitrary" inverter behavior and also documents that the configuration matches the requested strategy.

LED panel, fault mode and auto shutdown

Regardless of how the operating modes are set Growatt, you can read the system status from the panel with an OLED screen and eight indicators - from PV status, through the network and GEN port, to communication and battery operation direction; a button below the panel toggles the information on the screen. The indicator layout is from Table 7.1: system, PV, network/GEN, off-grid, battery, communication, and battery direction (charge/discharge). For the service technician, the last two are most valuable: the communication indicator also signals "other system faults," and the battery direction indicator allows you to confirm at a glance whether the selected mode is actually working as it should—for example, whether the Battery First battery is actually charging at midday. In fault mode, the corresponding indicator lights red, and the OLED displays an alarm or fault; once the cause is removed, the indicators return to green. The meaning of the individual codes is described in a separate article in the error code knowledge base. WIT 4-15K-HU - From an operating modes perspective, one thing is important: the failure mode takes precedence over any user setting.

Automatic shutdown occurs when the battery SOC drops below the discharge cut-off threshold and the PV string power is insufficient for grid operation – and absolutely when the PV voltage is below 150 V or the battery voltage is below 40 V. In this state, the inverter is not "broken": it draws minimal energy (from PV, grid, and battery, respectively) and waits for the start conditions to return. Growatt have no influence on this - the shutdown thresholds operate regardless of the selected configuration. Winter calls "inverter turned off in the evening" mostly describe this mechanism precisely.

Finally, a documentation issue: Chapter 7 of the manual in revision 2025-11 describes all of the above behaviors across nine pages (48–56), and we'll refer to them for each number in this article. If you're configuring a unit with a different firmware or from a different batch, first compare the mode names visible in the app with those in the manual before transferring any settings one-to-one to the new unit—the menu system is updated more frequently than the document itself, and a name mismatch is the first sign that you're looking at a different logic revision.

What NOT to do when configuring modes

Incorrectly set operating modes Growatt They rarely damage equipment—they damage bills and customer trust. The four configuration errors that return most frequently during service are all direct violations of the manual:

• Do not leave two inverters at address 1. When working in parallel with RS485, each unit requires a unique address in the range 1-254 - a duplicate address means chaos in the communication of the entire chain.
• Do not connect another brand inverter via AC Couple. The manual requires an inverter Growatt with the same security certificate number as PCS - the promise "we will achieve any on-grid to GEN" ends with disassembly.
• Do not skip setting the time after storage. After more than a month in storage, the inverter may have the wrong time, which needs to be set before connecting to the grid - otherwise the TOU schedules execute at the wrong times.
• Don't count on exporting battery power outside of Grid First. In Load First, ECO and Self-consumption, the battery does not release energy into the grid - if the customer wants to sell from the warehouse, it is only Grid First.

From the installer's practice

• Modes of operation Growatt configure after connecting the meter, not before: Load First without a meter or three CTs there is no way to close the measurement loop and the export limit works blindly.
• When receiving the installation, take a screenshot of the set mode, export limit and TOU schedule - three screenshots that will determine whether anyone has changed the configuration in the event of any later complaints.
• You generate the password for time settings from the current date ("growatt” + YYYYMMDD) - do not save it permanently in the client's records, because tomorrow will be different.
• With the Peak Shaving strategy, select thresholds A and B from the customer's tariff, and remember the hierarchy from the instructions: Peak Shaving wins with TOU, TOU with parameters - start each diagnosis of "why the inverter does something different" from this order.

Frequently asked questions about operating modes Growatt (FAQ)

What password opens the time settings in WIT 4-15K-HU?

The password consists of the word "growatt” and the current date in the format YYYYMMDD — February 28, 2024 would be “growatt20240228″. You enter it in the application after selecting Control > Set Inverter Time.

Why does the inverter turn off in the evening?

This is a mechanism from the manual, not a fault: when the PV voltage drops below 150 V or the battery voltage below 40 V, WIT It automatically turns off and waits for the start-up conditions to return, drawing minimal energy. In the morning, after the string voltage exceeds 150 V, it returns automatically via standby mode and a self-test.

Which operating modes Growatt allow you to sell battery energy?

Grid First only – where excess battery energy is directed to the grid for revenue. Load First, ECO, and Self-consumption export only excess PV, and only when the export limit is disabled.

When are a meter or CT transformers needed?

The instruction requires a meter or three CTs in Load First mode and a meter in the "zero export to meter" variant. The "zero export to GRID" variant operates without metering—the inverter simply does not output power to the GRID port.

Why does a turned off inverter still consume energy?

The shutdown mode is not a shutdown: the inverter consumes a small amount of power while waiting for restart conditions and draws it in the order of PV, then grid, then battery. Automatic shutdown occurs when the SOC drops below the discharge cutoff threshold and the PV string power does not meet the grid operation requirements—this is the design behavior of all operating modes. Growatt, not a fault.

Step-by-step configuration checklist

1. Set communication address (parallel: unique 1-254 per unit).
2. Set the time and date with the password "growatt+data" or connect to the server and allow synchronicization.
3. Select a mode from the matrix above and consciously set the export limit - operating modes Growatt and export limit treat as a pair of settings.
4. Connect and check the meter/CT if the mode requires it (meter arrow towards the inverter).
5. Apply strategies (TOU, Peak Shaving) remembering the hierarchy: Demand management > TOU > parameters.
6. Make configuration screenshots for the acceptance documentation.

Complete set of materials: user manual WIT 4-15K-HU, quick guide i catalog card are in our documentation database, and the originals are also in download center GrowattThe selection of batteries for storage modes is described in the article about batteries for WIT 4-15K-HU, and he will count it inverter + battery configuratorWe keep the scope of the article strictly: the behaviors described above concern WIT 4-15K-HU according to the manual revision 2025-11 — in other series, the mode names may be similar, but check the priorities and thresholds in the appropriate document. You can find this equipment in our offer: Growatt WIT 5KW-HU, battery pack 5 kWh for WIT 4-15K and the entire category 3-phase hybrid inverters.

Sources

1. Growatt WIT 4-15K - User Manual (HU) — user manual WIT 4-15K-HU (rev. 2025-11), chapter 7, PDF pp. 52-60 (print 48-56)
2. Growatt WIT 4-15K - Quick Reference Guide (HU) — quick guide WIT 4-15K-HU
3. Growatt WIT 4-15K - Catalog Card — catalog card WIT 4-15K