Parikkalan Valo and Norelco: the best product development ideas result from collaboration

The electrical network of Parikkalan Valo Oy covers Parikkala, Savonlinna, Rautjärvi, Ruokolahti and Kitee in South-East Finland. The company has been Norelco’s customer for more than a decade, and the two companies have been co-operating on the product development of transformers all this time. 

The distribution system operator Parikkalan Valo has approximately 10,000 customers. The network maintained by Parikkalan Valo totals around 3,000 km. 

“Here, the network length per consumption point is 300 metres, whereas in southern Finland the figure is around 17 metres per consumption point, which illustrates well the special nature of our operating area. In this operating environment, reliability of distribution as per the Electricity Market Act and security and safety covering all our operations are important factors,” says Parikkalan Valo’s Network Manager Hannu Ahokas.

Safe operation: continuous product development and standardised solutions in production

Parikkalan Valo’s kiosk-type transformers feature several technical solutions that have been standardised in the delivered transformers. An example of these is the net ceiling that is suspended above the MV network space to further increase safety inside the transformer.

“The net ceiling is a safety element between the transformer space and the disconnector cells. It prevents anyone working inside the transformer from accidentally coming into contact with the live disconnector cells by ensuring that limbs and tools stay inside the transformer space. The ceiling is also easier to remove, when replacing a – possibly live – transformer,” Ahokas explains. 

The safety and flow of work has also been improved in other ways; sometimes with small solutions, such as developing luminaires that are better suited to the workspace. Other standardised solutions in Parikkalan Valo’s transformers include worker protection for each disconnector and over-voltage protection in all cable outputs. 

“Our development work is based on safety and reliability in use. We get product development ideas through feedback from the installers and in connection with inspections. Every issue, big or small, is worth exploring together,” Ahokas says.

Targeting long-term transformer reliability: a robust concrete plinth guarantees that the transformer remains intact

This year, Parikkalan Valo has installed only arc fault tested kiosk-type transformer substations of the type 310 in its operating area. To this purpose, Norelco engineered a concrete plinth to replace the standard steel plinth. Concrete plinths were used in Finland in all kiosk-type transformers until roughly the late 1990s. Since then, they have been phased out to a large extent. 

“However, our view is that it is worth paying a little extra for the concrete plinth, since in the long term, say 30 to 40 years, a transformer installed on a concrete plinth is more resistant to the Finnish weather conditions. It prevents deformation damage caused by ground frost, among other things. It means that, for example, the doors work better,” Ahokas explains.

“Our customer relationship with Norelco is built on excellent communication with all the contact persons. We share our experiences and make product improvement proposals, and Norelco has always listened to us and taken our proposals to production,” Ahokas adds. 

Kiosk-type transformers delivered directly to the site

Parikkalan Valo’s 3,000-kilometre electrical network has around 200 transformer substations, and the company chose Norelco to deliver the products. Hannu Ahokas mentions two strong arguments for the choice. 

The first is Norelco’s local presence and delivery reliability. The second is the quality of the products and strong co-operation with a heavy focus on product development.

“We order the kiosk-type transformers from Norelco as just-in-time deliveries. We receive them at exactly the right time when everyone working at the site is ready to receive the transformer. This helps us avoid unnecessary storage costs or double transportation costs,” Ahokas says. 

For Norelco, delivery reliability is just as important as for the DSOs in terms of their own customers. 

“When the deal is closed, we manufacture the products to an agreed schedule and deliver them according to the situation at the customer’s worksite. This operating model has been honed in co-operation with the customer. After all, you can never be sure how, for example, the weather conditions affect the progress of the customer’s project,” says Joonas Pentikäinen, who works as Product Manager at Norelco and is a contact person for Parikkalan Valo.