Siemens 3SE5050-0GA00 Accessories and spare parts. Siemens 3SE5050-0GA00 is the exact printed commercial reference for a limit or safety switch in the SIRIUS 3SE range. Siemens' official product description is: Contact block IP20 for position switch 3SE5250 open type design 1 NO/1 NC quick action contact 2 x 2 mm contact clearance.