3RV Molded Case Motor Starter Protectors up to 800 A General data Function Trip units The 3RV1 molded case motor starter protectors for up to 800 A are available with four different trip units. 1) TU = Trip unit Protection function R Against rotor lockin Protection function I For instantaneous short- circuit protection Protection function L Against overloading of the motor Protection function U Against phase failure or phase unbalance Specifying the mode of operation Always set to CB CLASS Trip classes of motor according to IEC 60047-4-1 MAN/ELT Always set to MAN Choice between:
- input for PTC 1) temperature sensor - generic input 1/0 1) A special input is available for connecting a PTC temperature sensor which can be inserted in the motor to be protected. NSB0_01987a 3RV10 molded case motor starter protectors with trip unit TU 4 Trip classes Safe switch position The trip classes of thermally delayed trip units are based on the tripping time ( t A ) at 7.2 times the set current in cold state (ex- cerpt from IEC 60947-4): CLASS 10A: 2 s t A CLASS 10: 4 s t A CLASS 20: 6 s t A CLASS 30: 9 s t A The toggle lever indicates tripping by adopting the "Tripped" po- sition.
To prevent switching onto an existing fault, the lever must be moved by hand to the 0 position prior to switching on again. Only then can the molded case motor starter protector be swit- ched on again. The molded case motor starter protector must trip within this time! With the 3RV1 molded case motor starter protectors (100 A to 630 A) which are equipped with the TU 4 trip unit, all four trip classes are possible. 44 Siemens · 2009 Type1) Tripping method For molded case motor starter protectors Function Setting range External overload relay required for overload protection TU 1 Purely magnetic 1 ... 12.5 A Short-circuit protection Non-adjustable:
13 x I N Yes TU 2 Purely magnetic 20 A, 32 A Short-circuit protection Adjustable: 6 ... 13 x IN Yes TU 3 Electronic (for starter combi- nations) 100 ... 800 A Short-circuit protection Adjustable: 1 ... 10 x IN Yes TU 4 Electronic (for motor protec- tion) 100 ... 630 A Adjustable: No Overload protection I1 = 0.4 ... 1 x IN Short-circuit protection 6 ... 13 x IN Protection in the event of rotor blockage 3 ... 10 x I1