Accessing official IEC standards for free is generally not possible because they are copyrighted and sold to fund the standardization process. However, you can access the standard through several authoritative platforms:
The standard applies to traction fixed installations, rolling stock, and auxiliary devices across a wide range of systems: Both passenger and freight lines. iec 60850 pdf free download link
You can obtain it from various national distributors like NEN (Netherlands) or SIS (Sweden) . Accessing official IEC standards for free is generally
This includes tramways, light rail, trolleybuses, and underground/elevated railways. and underground/elevated railways.