Arcteq delivered the AQ 2000 medium voltage arc quenching system to Stora Enso’s Anjala paper mill located in Inkeroinen, Finland. The 6kV switchgear retrofit project was implemented using the AQ 100 series arc protection system detecting the arc flash and triggering the arc quenching device. The Thompson coil based AQ 2000 system extinguishes the starting arcing fault by creating a controlled low impedance path for arc fault current to flow. The implemented system provides as fast as 5ms total arc elimination time.

“We were impressed by the re-usability of Arcteq’s quenching device “, says Harri Mörsäri – Engineering Manager at Stora Enso.

The project was initiated as the short circuit capacity of the circuit breakers was exceeded after removal of short circuit limiter due to power quality issues. Goal of the investment was to prolong the lifetime of the switchgear originally installed in 1976. As an alternative investment model Stora Enso considered replacing the entire switchgear lineup by a new one.

“The cost of implemented circuit breaker retrofit, and arc quenching technology was significantly less than brand-new switchgear lineup. Also need for shut down was shorter.”, says Harri Mörsäri.

Arcteq scope of supply in the project included also AQ-M215 motor and AQ-V211 voltage protection relays, commissioning services and training of Stora Enso specialists. The project was completed and commissioned in August 2017.

Stora Enso’s very first acquaintance with Arcteq was installation of Arcteq’s revolutionary Motor Commander, for protecting and controlling two of their 8 MVA synchronous motors.

“We were the first ones to buy and apply the Motor Commanders. The very first one was commissioned in December 2016”, Mr. Mörsäri adds.

Since then Arcteq has also supplied 2 and 3-winding transformer protections to the facility. This retrofit project was completed and commissioned in May 2018. The third Motor Commander installation is due in August 2018.

The 6kV switchgear from 1970’s is made safer by installing the AQ 2000 arc quenching device in the VT section.

AQ 100 arc protection and AQ-M215 motor protection relays in the 6kV switchgear