Use Beuth.de for the legal PDF link. Avoid "free download" sites to protect your computer and comply with copyright laws.
Free preview versions or archival copies are often hosted on community platforms like Scribd or CivilNode , though these may not always be the most current 2014 revisions. din 19704 pdf link
The standard is divided into three distinct sections to cover the lifecycle of a hydraulic project: DIN 19704-3: Electrical Equipment Standards - Scribd Use Beuth