Terminal blocks for boats & yachts – professional terminal strips for onboard electrics
Terminal blocks are the central distribution and connection unit of the onboard electrical system. They bring all the cables of the electrical installation together clearly, allow structured wiring and form the interface between switch panel, loads and supply cables. For onboard systems, terminal blocks are available for cable cross-sections from 4 mm² to 35 mm², as well as custom builds.
Selection at a glance
| Type | Load terminals | Main terminals + / – | Dimensions L × W × H | Price |
|---|
| RKL 10 | 10 terminal pairs: 6 × 4 mm² / 4 × 6 mm² | + 1 × 16 mm² / – 1 × 35 mm² (Cu bar) | 235 × 60 × 60 mm | €105.00 |
| RKL 14 | 14 terminal pairs: 7 × 4 mm² / 7 × 6 mm² | 4 × 16 mm² for + and – pole | 335 × 60 × 55 mm | €135.00 |
| RKL 16/4 | 16 terminal pairs: 10 × 4 mm² + 6 × 6 mm²; 4 control terminals 4 mm² | + 2 × 16 mm² (bridged) / – 1 × 35 mm² (Cu bar) | 355 × 60 × 60 mm | €179.00 |
| RKL 20 | 20 terminals 4 mm² | + 2 × 35 mm² (bridged) / – 1 × 35 mm² (Cu bar) | 350 × 60 × 60 mm | €175.00 |
| RKL 30 | 30 terminal pairs: 20 × 4 mm² + 10 × 6 mm² | + 2 × 35 mm² (bridged) / – 1 × 35 mm² (Cu bar) | 525 × 60 × 63 mm | €275.00 |
Values from the product data, prices as of 23 Oct 2026.
In brief: A professionally built terminal strip makes every wire of the onboard electrical system clearly assigned and accessible at any time – without laboriously tracing cables during maintenance, fault-finding or extensions.
What are terminal blocks and what are they used for in onboard electrics?
Terminal blocks are connection terminals assembled on a mounting rail (DIN rail) to form a terminal strip. In onboard electrics they serve as the central distribution unit where supply cables, load connections and control cables are brought together in a structured way. The terminal strip connects all circuits to the switch panel and allows clear, accessible documentation of the entire electrical system.
Which types of terminal blocks are available for onboard systems?
| Terminal type |
Cable cross-section |
Application |
| Main current terminals |
16 mm² – 35 mm² |
Main circuits, battery cables |
| Load terminals |
4 mm² – 6 mm² |
Load connections, control cables |
| Control & signal terminals |
small |
Measuring, sensor and control cables |
| Negative busbar |
integrated |
Central ground distribution |
| Individually labelled terminals |
as required |
Custom builds |
How does the integrated negative busbar work on terminal blocks?
On single-pole terminal strips, the negative terminals are connected at the factory and form a common potential. They therefore also act as the central negative busbar for all load connections. This considerably reduces wiring effort and replaces separate ground distribution points – all ground distribution takes place directly via the terminal strip.
Why are terminal blocks better than direct cable connections in onboard electrics?
Direct cable connections without terminal blocks are hard to document, hard to reach and time-consuming during fault-finding or extensions. A structured terminal strip offers:
- Clear assignment of every wire
- Quick access to all connections without having to trace cables
- Easy extension of the onboard system with additional terminals
- Professional documentation of the entire electrical installation
- Greater operational safety through a clear structure
Custom terminal strips – made-to-measure strips for special applications
In addition to standard versions, terminal strips are also built individually to customer specification. Number, layout, terminal types and labelling can be matched exactly to the project – for sailing yachts, expedition vehicles, special vehicles and professional onboard installations with specific requirements.
Frequently asked questions about terminal blocks for boats and yachts
Which cable cross-sections do terminal blocks for onboard systems cover?
The range includes terminals for cross-sections from 4 and 6 mm² (load connections) up to 35 mm² (main circuits).
Are terminal blocks suitable for 12 V and 24 V systems?
Yes. The terminal blocks are suitable for 12 V and 24 V systems and can be used in mixed installations.
What is a negative busbar and do I need a separate one?
On single-pole terminal strips, the negative terminals are connected at the factory and take over the function of the negative busbar directly. A separate ground distribution bar is not needed in most cases.
Can terminal blocks be extended later?
Yes. The modular system can be extended at any time with additional terminals on the mounting rail – without rebuilding the existing installation.
Which vehicles and boats are terminal blocks suitable for?
Terminal blocks are used in sailing yachts, motorboats, catamarans, expedition vehicles, motorhomes and special vehicles – wherever structured, safe and easy-to-maintain onboard electrics are required.
Are custom builds possible?
Yes. Terminal strips are built individually to customer specification on request – with defined assembly, labelling and terminal types.
