JRS8(T) series thermal relays are suitable for elec．power system with rated insulating voltage upto 660V，rated current upto 500A for overload and phase failure protection．
　　It can be matched with B series AC contactors to form AC magnetic starters．
Structure
　　JRS8(T)-16，25 series thermal relays are friction type tripping mechanism with protecion of phase failure；JRS8(T)-45，85 series are spring type with protection of phase failure，JRS8(T)-105，170 series backpack type，and JRS8(T)-250，370 series are jumping type with C.T.