Triangular Ring Main Unit

The internal structure of a ring main unit is carefully designed for efficient layout and cable management. The unit consists of a large metal enclosure with multiple cabinet sections arranged in a structured configuration.
A typical setup includes one DTU cabinet installed on the side, and eight cabinets arranged in the front section. Among these, one is a PT cabinet, while the remaining seven are feeder cabinets. Specifically, two are incoming feeder cabinets and five are outgoing feeder cabinets, forming a 2-in, 5-out configuration.
This triangular ring main unit design can be customized according to project requirements. The arrangement sequence of the cabinets is also important, as a well-planned layout ensures clear cable routing and minimizes electrical interference.

The incoming feeder cabinets manage power input and loop distribution, while the outgoing feeder cabinets supply power to downstream loads. One of the key advantages of this triangular ring main unit is its high system reliability.
Most modern units adopt gas-insulated technology, in which key components such as circuit breakers are installed in a sealed compartment filled with insulating gas. This significantly reduces the overall size of the equipment, saving space and simplifying installation.
The internal electrical components include circuit breakers, isolating earthing switches, current transformers, and voltage transformers. We provide a 1-year warranty for every triangular ring main unit.

The green component shown in the diagram is a three-position switch. This design is highly efficient, as it combines the isolator and earthing switch into a single operating mechanism, reducing space requirements and simplifying operation.
When the operating handle is in the middle position, both switches are open. When turned to the right, the isolator closes. When turned to the left, the earthing switch closes.
We manufacture this triangular ring main unit in our own factory. You can start with just one unit for evaluation. If any issue occurs, we will assess the problem and provide replacement parts promptly-no excuses. Contact us for your next project.