Overload relay 0.32...1.25 a for motor protection size s00, class 10 contactor ass. main circuit screw conn. aux.circuit screw conn. manual-autom.-reset
Modified Industry Description
.32 TO 1.25A SOLID STATE OVERLOAD RELAY, 3 PHASE, SELECTABLE AUTO/MANUAL RESET
SIRIUS 3RB30161NB0 Solid State Overload Relay, 1NO-1NC Contact Form
The 3RB20 and 3RB21 solid state overload relays up to 630 A with internal power supply have been designed for inverse time delayed protection of loads with normal and heavy starting (see technical information LV 1 T, "Function") against excessive temperature rises due to overload, phase unbalance or phase failure. An overload, phase unbalance or phase failure result in an increase of the motor current beyond the set rated motor current. This current rise is detected by the current transformers integrated into the devices and evaluated by corresponding solid state circuits which then output a pulse to the auxiliary contacts. The auxiliary contacts then switch off the load by means of a contactor. The break time depends on the ratio between the tripping current and current setting Ie and is stored in the form of a long term stable tripping characteristic.