Ensto’s comprehensive ABC protection solutions for low voltage

There are many reasons for fault situations and service breaks in the power grid. They can cover trees falling on an overhead line, extreme weather conditions, birds and small animals, and excavation or maintenance work, to mention some.

The aim of Ensto’s ABC (Aerial Bundled Cable) protection solutions for low voltage networks is to minimize the faulty area, shorten the cut-off time and finally, guarantee uninterrupted power distribution to the end users even during malfunction of the line. Ensto’s international solutions are suitable for various aerial bundled cable systems and are designed to meet the local conditions and requirements considering various conditions in urban, rural, and forested areas, the density of population and climate.

Same challenges, various solutions, one Ensto umbrella

There are many ways of protecting the low voltage overhead line networks in various countries, but everywhere, the challenge is the same: how to prevent the power from cutting in fault situations. Ensto’s protection solution umbrella covers it all by short circuit protection, overload protection, section switch, and temporary earthing place. Our solutions offer products and integrated product packages for every specification and type of protection, and hence, the customer can select the alternative that best suits his needs.

Unbeatable benefits of low voltage ABC protection

The protection of low voltage ABC saves money, time, and the environment. Our products are easy to install and use, and their reliability and safety has been proved in numerous tests in accordance with IEC and national standards. The life-cycle impact of the products on the environment has been minimized. The most unbeatable benefit are the happy end users of electricity: the consumers.

Ensto has decades of thorough knowledge and experience of building and protecting low voltage overhead line networks in several countries worldwide and together with hundreds of customers. As result of vigorous product development, the ABC protection products meet even the most demanding local and international requirements.

Pole fuse switch disconnectors for safe and easy protection

Ensto’s pole fuse switch disconnectors, combine the functions of a fuse, a switch, and a disconnector, which makes them a versatile choice. The products are favored by line installation professionals as thanks to a visible phase/fuse marking and operating rod they are easy to operate from the ground.

Topi Virtanen, Ensto’s Product Manager for overhead line networks tells, that the SZ160 and SZ400 products families are super popular.

"Our customers appreciate that our products have separate terminal covers, which together with installation videos guarantee a safe and easy installation". He continues:


“The product structure and locking mechanism are robust which stand for proven, long lifetime in the grid, even in the most severe conditions. The disconnectors save the customers’ money!”

Mr Virtanen states that it cannot be taken for granted that the product today is type-tested. “Our products are - and that is a huge benefit for the customers. The materials like solid aluminum and glass fiber reinforced plastic are of high-quality and have high-quality characteristics like resistance to UV radiation and abnormal heat and fire.”

The Ensto pole fuse switch disconnector product assortment has been widened to cover various needs and types of protecting the grid from service breaks. Our another pole fuse switch disconnector RY150450 is tailor-made for the UK and Ireland grids, but they are also suitable for other markets. The products are like pole fuse switches presented above. As the fourth pole is a fixed solid neutral connection, it is opened and closed together with the other phase-poles. The low voltage ABC protection products are ideally complemented with durable Ensto overhead line accessories.

Cost-efficiency for transformer protection with circuit breakers

Ensto's pole-mounted low voltage circuit breakers D165T and D265T with digital trip unit are used for protecting and managing overhead line medium/low voltage transformers in rural areas. They are adapted to significant load imbalances and guarantee the uninterrupted distribution of electricity to the end customers even in unbalance conditions.

Pascal Pedrinelli, Director, Products & Services Network Automation confirms that using the low voltage circuit breaker brings intelligence in the transformer protection.

“The main advantage of circuit breakers with digital trip is that the device observes the transformer behavior by following the thermal image of it and switching the power off when the load reaches the limit level.”

After inspecting the defected line, the power is switched on again with a rod by a utility technician.

The devices use air-break technology with chambers with metal partitions to cut the arc. Mr Pedrinelli continues: “Utilities’ investments in their transformers are truly optimized with our circuit breakers. As the low voltage circuit breaker brings reactivity to trip when needed without any damage to the transformer, the operating life of the transformer will be longer, and the return on investment better.”

When compared to fuse protection in a cabinet, the circuit breaker saves money as the fuses don’t need to be changed. The fuseless solution is also safe as there is no risk of incorrect replacing of fuses.

The circuit breakers are easy to install and maintenance-free.

The devices can be selected based on customer needs regarding the size of the transformer, fixing support, type of rod assembly, trip unit type, and load indicator option.

What comes to environmental aspects, the circuit breaker is a compact solution. It can easily be re-used and due to less raw material used in design, it is lighter in weight. In addition, it produces less waste as there are no used fuses to be thrown away and at the end of the lifecycle, can be fully recycled.