Mounting & Installation - K2 Systems - Flat Roof
The ‘Assembly & Installation’ section covers the materials used to turn modules, inverters and air conditioners into a complete system: the roof substructure, solar cables and MC4 connectors, crimping and assembly tools, as well as brackets and copper pipework for split air conditioners. The majority of these are supplied by K2 Systems (assembly systems) and Stäubli (connectors, cable assembly and tools).
Important to note in advance: This category offers PV mounting materials and installation materials for sale; it does not include any services. ACTEC does not offer any assembly or installation services. You are responsible for organising the installation yourself. The electrical connection and work on the refrigerant circuit must always be carried out by a specialist contractor.
Three areas: roof, cabling, air conditioner
The substructure for PV systems connects the modules to the building. For pitched roofs, there are roof hooks for various types of roofing, including specific hooks for slate and metal roofs, as well as hanger bolts and the SingleRail 36 and SolidRail Light rails in lengths from 2.40 to 5.95 m. On double-seam standing seam roofs, the CF:x seam clamp secures the rail without piercing the sheet metal. The MiniRail and BasicRail 22 systems are available for trapezoidal sheet metal. On flat roofs, the east-west mounting system D-Dome 6.10 is used, which is also available as pre-assembled installation kits for 2 to 12 modules.
PV installation materials cover the cabling from the module to the inverter and on into the house: H1Z2Z2-K solar cables with cross-sections of 4 and 6 mm², a green-and-yellow cable with a 16 mm² cross-section for equipotential bonding, in-line fuses and Y-splitters from Stäubli, connection cables for storage systems from Growatt and SAJ, and Schuko connection cables for micro inverters. The connectors are from Stäubli: plugs and sockets from the MC4 and MC4-Evo 2 systems for conductor cross-sections from 4 to 10 mm², branch connectors and sealing caps. Crimping pliers, wire strippers, assembly wrenches and test probes are all available in the tools section for MC4 connectors.
For split air conditioners, the installation kit for air conditioners includes wall brackets for the outdoor unit and installation kits with brackets and copper pipework in various lengths.
What should be clarified before ordering
Three factors determine the bill of materials for the substructure. The roof covering determines which roof hook or fastening is suitable. The frame height of the modules determines the clamps: the centre and end clamps in the range are designed for specific ranges, such as 25 to 40, 30 to 42 or 30 to 50 mm. Finally, the number and orientation of the modules determine how many metres of rail, connectors and end caps are required.
When it comes to cabling, the cross-section and connector system are key. The cross-section is determined during the planning stage based on current and cable length; a larger cross-section minimises losses over long runs. Connectors may only be connected to counterparts from the same manufacturer and the same series, and they are crimped using the tool specific to that system. Neither of these features is visible from the outside of the finished connection, which is why the appropriate tool must be included in the order.
What the kits do not include
The complete PV sets consist of modules, an inverter and, depending on the set, a storage unit. The substructure and DC solar cables are not included in any set, as they depend on the type of roof, roof pitch and cable routing. Depending on the version, the balcony power plant sets include either a Schuko connection cable or a Y-splitter, but under no circumstances do they include a mounting bracket. A mounting bracket for balcony railings from Hantech is listed under ‘Support structure’.
This is not the case with the flat-roof kits from K2 Systems: these include base profiles (Base Set), mounting brackets, end clamps and ballast supports in quantities suitable for 2, 4, 6, 8, 10 or 12 modules; from four modules upwards, they also include centre clamps and cable ties. The ballast blocks themselves are not included; the quantity required is determined by the planning for the specific roof.
Installation, connection and registration
A structural analysis determines whether the roof can bear the additional load, particularly in the case of a ballasted mounting system on a flat roof. The connection of a photovoltaic system to the domestic electricity supply is carried out by a qualified electrical contractor registered with the network operator. The contractor also registers the system with the network operator.
Split air conditioners are filled with fluorinated refrigerant. Work on the refrigerant circuit must be carried out by personnel certified in accordance with the F-Gas Regulation (EU) 2024/573. The documentation required when purchasing an air conditioner kit is set out on the page Professional installation of your air conditioner.
For photovoltaic systems and their essential components, no value added tax is charged where the conditions of Section 12 (3) of the German VAT Act (UStG) are met. You state during the ordering process whether they apply to you. Installation materials for air conditioners are not included.
Frequently asked questions about fitting and installation
Does ACTEC offer fitting or installation services?
No. ACTEC supplies the materials for assembly, but does not provide an assembly or installation service. You must commission a specialist contractor of your choice to carry out the assembly, the electrical connection and, in the case of air conditioners, work on the refrigerant circuit.
Which substructure is suitable for my roof?
This depends on the type of roof covering. On a pitched roof, the rails are supported by roof hooks or anchor bolts; on a double-seam standing seam roof, the CF:x seam clamp is used; on trapezoidal sheet metal, the MiniRail and BasicRail 22 systems are used; and on a flat roof, the east-west mounting system D-Dome 6.10, with ballast, is used.
Are the substructure and cables included in the complete PV kits?
No. The kits contain modules, inverters and, where specified, the storage unit. You select the substructure and solar cables to suit your roof and cable routing.
What cross-section do solar cables need?
Our range includes solar cables with cross-sections of 4 and 6 mm². The appropriate size depends on the current and the length of the cable run. For equipotential bonding, there is a green-and-yellow cable with a cross-section of 16 mm².
What tools do I need for MC4 connectors?
A crimping tool with the correct insert and locator, a wire stripper, a spanner for tightening the screws, and a test probe. Stäubli also offers all of these items together in a tool kit at MC4 and MC4-Evo 2.
Can I connect the photovoltaic system myself?
Connection to the domestic mains supply and registration with the network operator must be carried out by a registered electrical contractor. It is best to clarify with this contractor which tasks you can carry out yourself beforehand.