JRS2(3UA) series thermal overload relay are suitable for overload and phase-failure protection of AC motors with frequency of 50/60Hz,voltage up to 690-1000v,current up to 0.1-400A under 8-hours duty or uninterrupted duty. Several functions provided by these relays are: phase-failure protection, temperature compensation, ON/OFF indication and manual/automatic reset. The relays can be mounted onto contactors or installed as single units.