Some time ago, ABB started the work of planning the renewal of low voltage switchgears at Altia's Rajamäki plant in Finland. In the scope of this project, an update of the protection relays was also included. When ABB took inventory on the equipment in use at the time, we were very pleased to discover that the relays still in use were two SCAU-type relays. The SCAU relays were in large-scale production in the early 1970s, which meant they had worked flawlessly for 40 years. For a protection relay that is a very respectable age.
"It's unusual to hear about 40-year-old static relays still in use, as the estimated life span for electronic components is on average 25 years. For the relay components, air temperature and humidity are very important factors affecting the life of the products. Thanks to the favorable installation environment at this plant, these relays almost doubled their life span", says Timo Vedenjuoksu, area sales manager at ABB.
Image 1. The label for the 40-year-old switchgear's layout drawing
Altia has confidence in ABB products
The resilience and longevity of these relays ensured customer confidence in ABB's products and when the time came to renew the 400 Volt main power centers' equipment at the Rajamäki plant, Altia chose to replace the 40 year old relays with ABB's CM phase balance current relays.
Tero Okkonen, real estate technician at Altia, comments "We expect that the new relays will be durable, functional and easy to maintain. I believe that these new relays will also have a long life span. However, replacing these relays is likely to take place before 40 years has passed."
At the Rajamäki plant, Altia manufactures and packages alcoholic beverages. The production at this plant started in 1888 and today it produces over 65 million liters of beverages annually on its seven bottling lines.
History and retirement plans for the SCAU relays
The manufacturing of the SCAU relays were originally started by the company Strömberg, which later became part of ABB. The development of static protective relays started at Strömberg in the mid-1960s. The SCAU relays are part of the J-series.
The retired SCAU relays are now showcased at the Relay Hall of Fame at ABB's Medium Voltage Product unit's factory in Vaasa, Finland.
Image 2. The relays will spend their retirement days showcased at the Relay Hall of Fame
ABB's life cycle services for protection relays
There are over one million ABB distribution protection relays of different age in use at utilities and industries all around the world. ABB provides product support for the users throughout the products' entire life cycle. One example is the preventive maintenance concept for selected relays, which has been developed to prolong the relay's life and maintain protection capability. Relays that have gone through systematic life cycle service operations maintain their efficiency and have a long life.
