Solid-State Overload Relays Block 3RB2123_63

Features and technical specifications:
1. Overload protection, phase failure protection and unbalance protection
2. Internal ground-fault detection (activatable)
3. Internal power supply
4. Auxiliary contacts 1 NO + 1 NC
5. Manual and automatic RESET
6. Electrical remote RESET integrated
7. Switch position indicators
8. TEST function and self-monitoring

This Solid-State Overload Relays Block is easily insert in your schematic diagram and connect as you like way.

(1)Connection for mounting onto contactors : Optimally adapted in electrical, mechanical and design terms to the
contactors and soft starters, these connecting pins can be used for direct mounting of the overload relays. Stand-alone installation is possible as an alternative (in some cases in conjunction with a stand-alone installation module).
(2)Selector switch for manual/automatic RESET and RESET button: With the slide switch you can choose between manual and automatic RESET. A device set to manual RESET can be reset locally by pressing the RESET button. On the 3RB21 a solid-state remote RESET is integrated.
(3)Switch position indicator and TEST function of the wiring: Indicates a trip and enables the wiring test.
(4)Solid-state test (device test): Enables a test of all important device components and functions.
(5)Motor current setting: Setting the device to the rated motor current is easy with the large rotary knob.
(6)Trip class setting/internal ground-fault detection (only 3RB21): Using the rotary switch you can set the required trip class and activate the internal ground-fault detection dependent on the start-up conditions.
(7)Connecting terminals (removable joint block for auxiliary circuits): The generously sized terminals permit connection of two conductors with different cross-sections for the main and auxiliary circuits. The auxiliary circuit can be connected with screw terminals and alternatively with spring-loaded terminals. The 3RB20/3RB21 solid-state overload relays are suitable for customers from all industries who want to guarantee optimum inverse-time delayed protection of their electrical loads (e. g. motors) under normal and heavy starting conditions (CLASS 5 to CLASS 30), minimize project completion times, inventories and power consumption, and optimize plant availability and maintenance management. The 3RB20/3RB21 solid-state overload relays have been designed for the protection of induction motors in sinusoidal 50/60 Hz voltage networks. The relays are not suitable for the protection of single-phase AC or DC loads. The 3RU11 thermal overload relay or the 3RB22/3RB23 solidstate overload relay can be used for single-phase AC loads. For DC loads we recommend the 3RU11 thermal overload relay.The devices are insensitive to external influences such as shocks, corrosive environments, ageing and temperature fluctuation. For the temperature range from –25 °C to +60 °C, the 3RB20/3RB21 solid-state overload relays compensate the temperature according to IEC 60947-4-1. For the 3RB20/3RB21 solid-state overload relays with the sizes S6, S10 and S12, the upper set value of the setting range must be reduced for ambient temperatures > 50 °C by a certain factor.