Insulation class: E (120 max.) Ambient temperature: -20+45(+65) Storage temperature: -50+80 Test voltage:4KV 50Hz 1min Operating frequency: 50Hz/60Hz Rated secondary current: 5A or 1A Rated burden: 1VA, 1.5VA, 2.5VA, 3.75VA, 5VA, 7.5VA, 10VA, 12.5VA, 15VA, 20VA, 30VA, 45VA, 60VA Class of accuracy: 0.5 for exact measuring, (for kWh measuring), 1.0 for general measuring with switch board instruments, 3.0 for other not so exact measuring. Connection: the secondary terminals are with two connection (on the each side) connection is solved with M4(M5) screws which can be handled easily and secure low contact resistance. Accessories: the terminal cover is executed to assure the lead seal. this execution complies with the VGB4 protection of DIN 57106 standard.