Refurbishment programme for drives

An extensive low voltage AC drive refurbishment programme has been carried out by ABB on a series of drives used at UPM Shotton Paper's recycled fibre plant (RCF). The RCF is a critical process, feeding the paper machines which produce more than 500,000t of newsprint per year.

To improve the performance of its installed drives base, cut downtime and lower the cost of repairs, UPM initiated a Focus Improvement Team tasked with identifying reasons for downtime on low voltage AC drives.

ABB was invited to join the team.

It was found that the ABB drives were suffering from dry solder joints on the power semiconductor units.

Although natural degradation and a common occurrence with drives, it was happening outside normal warranty. However, ABB offered to support UPM with replacement units.

Using ABB's service workshop at St. Neots, the refurbishment, phased in over six months, included replacing power semiconductor modules and fans in 36 drives (from 160 to 560kW).

Any components identified as faulty were replaced after agreement with UPM Shotton.Up to four drives at a time were refurbished during shorttime shutdowns at the plant. Two standby drives were supplied to cover those being refurbished.