Case Study: Southern Peru Copper Corporation achieves better power quality and keeps mills online with Schweitzer Engineering Laboratories point-on-wave controlled closing

Southern Peru Copper Corporation cuts transformer inrush current from 2.5 pu to less than 1 pu with Schweitzer Engineering Laboratories

Southern Peru Copper Corporation, one of the largest copper producers in Peru, faced a challenge with power quality at a key substation. Their existing control device for point-on-wave closing was malfunctioning, causing high inrush currents and voltage drops whenever transformers were re-energized after maintenance. This resulted in the loss of sensitive rock-crushing mill loads, which are critical for their around-the-clock mining operations.

Schweitzer Engineering Laboratories (SEL) implemented a solution using an SEL-352 Breaker Failure Relay to provide precise point-on-wave closing control. This technology reduced transformer inrush current from 2.5 pu to less than 1 pu, minimizing voltage drops and keeping the mills online. The improved power quality preserved operations availability and prevented significant production and revenue losses for the mining company.

Southern Peru Copper Corporation