IEC/EN 61810-1, UL 508, CSA C22-2 n° 14. UL, CSA. Schneider Electric Zelio RSB Series Relays. A range of Schneider Electric interface relays from the Zelio series. These plug in Relays are suitable for standard applications. Simple installation and operation Contacts material silver alloy (Ag/Ni) DC or AC coil Operating temperature -40 70 °C Ingress protection IP40