The www.abb.com/substationautomation portal provides information on the entire range of distribution automation products and services.
The latest relevant information on the RET615 protection and control relay is found on the new.abb.com/medium-voltage/distribution-automation/numerical-relays/transformer-protection-and-control/transformer-protection-and-control-ret615-iec. Scroll down the page to find and download the related documentation.