Installing the inverter WIT The 4-15K-HU begins with grounding and ends with grid parameter verification—and this order is not arbitrary. The manufacturer requires that the protective conductor be connected before any other conductor, with a tightening torque of 50 kgf·cm. Correct inverter installation WIT It also requires maintenance clearances of 0,6 m on the sides, 0,6 m above and below the device, and 1 m in front. Below you'll find the complete procedure from unpacking to startup, with parameters from the manufacturer's manual and a list of errors that most often result in service calls.
Installing the inverter WIT — installation site conditions
The inverter has an IP66 rating, making it suitable for indoor and outdoor installation. The manufacturer specifies an ambient temperature range of -30°C to 60°C and a relative humidity range of 0% to 95%. The device can be mounted vertically or tilted backwards; horizontal, forward-tilted, or ceiling-mounted installations are not permitted.
A separate caveat concerns sunlight. The instructions explicitly advise against exposing the device to direct sunlight, as high temperatures can reduce power output. A south-facing facade without a roof is the worst possible choice, even though the protection level formally allows it. A north-facing wall, a shaded recess, or a roof solve the problem at no additional cost.
| Installation location parameter | Manufacturer's requirement |
|---|---|
| Level of security | IP66 - indoor or outdoor |
| Ambient temperature | -30 ° C to 60 ° C |
| Relative humidity | 0-95% RH |
| Position | vertical or tilted back |
| Space on the sides | 0,6 m |
| Clearance above and below the device | about 0,6 m |
| Front space | 1 m |
| Insolation | avoid direct sunlight |
| Surroundings | away from sources of strong interference, out of reach of children |
Cable cross-sections and material preparation
The manufacturer provides recommended cross-sections in the quick installation guide. Preparing them before departure shortens the inverter installation. WIT a good half a day, because you don't have to buy anything on site.
| Wire | Type | Recommended cross-section |
|---|---|---|
| PE protective conductor | multi-strand copper (yellow-green) | 6 mm² |
| Mains / generator / load | multi-strand copper | 10 mm² |
| Input PV | solar PV cable | 4-6 mm² |
| Battery input | multi-strand copper (orange-black) | 50 mm² / 120 mm² |
| Communication COM1 / COM2 | standard 568B network cable | not specified in the instructions |
| Communication COM3 | multi-strand copper | 22 AWG |
The battery wire cross-section seems excessive until you calculate the current. At 51,2 V and 10 kW, the current draws nearly 200 A, so 50 mm² is the minimum, and for longer routes and full warehouse expansion, 120 mm² is required. The instructions also stipulate that aluminum wires should not be used – if the diameter doesn't fit the terminal or aluminum is involved, the matter should be addressed by the manufacturer, not by on-site improvisation.
Another detail that's easy to miss: not all PV ports are active in every model . In 4 kW, 5 kW, and 6 kW units, ports 2 and 3 are used, leaving port 1 unused. In 8 kW and 10 kW models, port 3 is operational, leaving port 2 free. Connecting a string to the wrong port results in no production from that part of the installation even if voltage measurements are correct—a fault that can take hours to track down.
You will find the complete material table in quick installation guide WIT 4-15K, and the connection details in full user manual — we keep both documents together with the catalog cards.
Installing the inverter WIT on the wall - drilling and moments
The wall mount also serves as a template for tracing. The manufacturer provides specific parameters that should not be taken at face value:
- Place the mounting plate against the wall and mark the drilling points.
- Drill holes 12 mm in diameter and 70 mm deep.
- Install the expansion bolts and tighten the handle mounting to a torque of 396 kgf·cm.
- Hang the device on the bracket and secure it with a screw with a torque of 50 kgf·cm.
A torque of 396 kgf·cm corresponds to approximately 39 Nm, and 50 kgf·cm corresponds to approximately 5 Nm. Tightening by feel with a socket wrench usually exceeds these values, and when mounting on a hollow brick wall, this leads to the plug being pulled out. A torque wrench at this stage is cheaper than a single device failure.
Before starting work, check the load-bearing capacity of the partition. Installing the inverter WIT together with the energy storage on the same wall means a load of hundreds of kilograms, because the battery module itself is 14,3 kWh weighs less than 120 kg, but it is always a mass concentrated in a small area.
The order of electrical connections when installing the inverter WIT
The manual clearly states this: the protective conductor must be connected first, before all other conductors, to prevent personal injury and damage to the device. The protective conductor terminals are waterproof, and the screws are tightened to a torque of 50 kgf cm. In addition to the enclosure grounding, the device has an internal grounding rail, to which the cable runs inside the enclosure. If the building has a lightning protection system, also check the connections between it and the inverter's grounding—we summarized the rules in the article on lightning protection for PV installations.
Correct sequence when installing the inverter WIT looks like this:
- PE protective conductor — always first, torque 50 kgf cm, clamps protected against rain.
- AC side terminals — moment 20 kgf·cm, after removing the lower housing cover.
- Internal grounding — wire to the copper grounding bar inside the housing.
- AC Page — mains connection in a 3P3W+PE or 3P4W+PE system, with overcurrent protection selected for the output current of the model.
- Emergency exit — a separate section of the switchboard with its own protection.
- DC PV website — with DC disconnectors in the off position, with polarity check before tightening.
- Battery — power cables and communications BMS via RS485 or CAN, including the battery temperature sensor cable.
- Communication and meter — bidirectional meter or three current transformers required in Load First mode.
Once the connections are made, the PG cable glands are tightened—they are responsible for the enclosure's tightness, so skipping this step undermines the declared IP66 protection rating. The bottom cover is only replaced after all the cables have been inserted, not before.
DC disconnects must be turned off before connecting anything. The manual also warns against moving the thick wire after tightening the terminal—a loose connection at currents of around 200A on the battery side is the most common cause of local overheating.
First start and configuration
The inverter enters standby mode when the voltage on the PV side exceeds 150 V. The actual start occurs after a successful self-test, at a voltage of at least 165 V. If the device does not wake up after switching on the circuit breakers, first check the string voltage, not the device itself. The switching order is fixed: first the battery circuit breaker, then the DC circuit breakers of the strings, and finally the AC protection – switching off is performed in reverse. This allows the inverter to recognize the storage before the voltage from the modules appears and does not report a communication failure. BMS.
The manufacturer emphasizes the importance of setting the date and time. An inverter stored for longer than a month may have an incorrect time, which must be set before connecting to the grid. An incorrect date later corrupts production monitoring data and complicates analysis of events during warranty claims.
The operating mode is also determined during the configuration stage. Load First requires a meter or three current transformers – without them, the inverter doesn't know how much the house is drawing, and the mode won't function as expected. The island operation parameters also need to be set: 50 Hz frequency and 230 V voltage for installations in Poland.
The device features AFCI (Arc Fault Detection) functionality on the DC side. The algorithm monitors the installation for arc faults, which can occur due to insulation breakdown or loose connections. This feature is optional in configuration, and it makes sense to enable it for rooftop installations on residential buildings.
Post-launch verification
Installing the inverter WIT ends only after verification, not when the device shows the first production. The practical scope of verification includes:
- measurement of voltage and current of each string separately and comparison with the design,
- control of communication with the battery and reading of the charge status,
- island operation test by disabling the main protection,
- checking the flow direction on a bidirectional meter,
- verification of the correctness of the date, time and time zone,
- registering the device in the monitoring portal and providing access to the client.
Installing the inverter WIT ends in the app, not at the terminals. Registering the device in ShinePhone Providing the customer with access to monitoring is part of the commissioning process: without it, the customer calls the installer with any questions, and the service center has no remote access to events. The account is created with the customer's details, not the installer's. When changing contractors, the production history remains with the installation owner.
It's a good idea to supplement as-built documentation with the serial numbers of the inverter and battery modules, as well as the software versions. This information can save you one trip to the facility during future warehouse expansion.
From the installer's practice
Don't shorten service intervals. The required meter of free space at the front is often the first thing to disappear when installing in a tight boiler room. When the casing needs to be removed or the device replaced after two years, the cost of the modification far outweighs the space savings. Plan to use two people to hang the device on the bracket, and check the weight of the specific model in the catalog before leaving.
Double-check the battery polarity. With low voltage and high current, a mistake can be costly. Reverse polarity protection is included in the device, but it does not eliminate the need to measure the battery with a multimeter before powering it on.
In practice, we often encounter installations in which the installation of an inverter WIT It was done correctly, but the Load First meter was forgotten. The customer calls after a week to ask why the energy is going to the grid instead of the battery, and the reason is a lack of measurement at the connection.
Take photos before closing the housing. Photographing the terminals, wire markings, and nameplate takes a minute and, with remote diagnostics, can replace a service visit.
FAQ
Is it possible to install an inverter WIT outdoors is acceptable?
Yes, the IP66 rating allows for outdoor installation. However, the manufacturer recommends avoiding direct sunlight, as high temperatures can reduce power output.
What tightening torques apply when fastening?
The wall bracket expansion bolts are tightened to a torque of 396 kgf·cm, the screw securing the device to the bracket and the protective conductor terminals to a torque of 50 kgf·cm.
What to connect first?
Protective earth. The instructions require that the earth be connected before all other conductors, with the DC disconnect switches turned off.
Why doesn't the inverter start after being turned on?
Most often, this is due to insufficient voltage on the module side. Standby mode activates above 150V, and start requires at least 165V after a successful self-test.
Assembly checklist
- Plan your inverter installation WIT: check the completeness of the delivery and the condition of the packaging before starting work.
- Verify the load-bearing capacity of the wall and maintain clearances of 0,6 m on the sides and 1 m in front.
- Drill 12mm holes to a depth of 70mm and install the bracket with a torque of 396kgf·cm.
- Connect the protective conductor first, with a torque of 50 kgf cm.
- Make AC, emergency output, DC and battery connections with circuit breakers turned off.
- Install a meter or current transformers if Load First mode is provided.
- Set the date, time, operating mode and island operation parameters.
- Perform an island test, register the device in the monitoring system and provide the documentation to the client.
8 kW models, as WIT 8K-HU, and ready Magazine Sets 10 kWh with complete wiring shorten assembly time because the components are factory-selected.
We have complete documentation for this series on our website: catalog card WIT 4-15K with full parameters and user manual with service proceduresThe source versions are also published producer.
