Overload Relays 3RB2 Solid-State Overload Relays 3RB22, 3RB23 for high-feature applications Recovery time With the 3RB22/3RB23 solid-state overload relays the recovery time after inverse-time delayed tripping is approx. 3 minutes re- gardless of the selected reset mode. The recovery time allows the load to cool down. Auxiliary contacts The 3RB22/3RB23 solid-state overload relays have two outputs, each with one NO contact and one NC contact. Their basic assig- nment/function may be influenced by function expansion mo- dules.
However, in the event of temperature-dependent tripping by means of a connected PTC sensor circuit, the device can only be manually or automatically reset once the winding temperature at the installation location of the PTC thermistor has fallen 5 Kelvin below its response temperature. The 3RB22 and 3RB23 differ with respect to the tripping characte- ristics of their auxiliary contacts – monostable or bistable: The monostable 3RB22 solid-state overload relays will enter the "tripped" state if the control voltage fails (> 200 ms), and return to the original state they were in before the control supply voltage fai- led when the voltage returns.
These devices are therefore espe- cially suited for plants in which the control voltage is not strictly monitored. After a ground-fault tripping the 3RB22/3RB23 solid-state over- load relay trips can be reset immediately without a recovery time. TEST function The combined TEST/RESET button can be used to check whether the relay is working correctly. The test can be aborted at any time by letting go of the TEST/RESET button. The bistable 3RB23 overload relays do not change their "tripped" or "not tripped" status if the control voltage fails. The auxiliary con- tacts only switch over in the event of an overload and if the supply voltage is present.
These devices are therefore especially suited for plants in which the control voltage is monitored separately. LEDs, the device configuration (this depends on which expansion module is plugged in) and the device hardware are tested while the button is kept pressed for 6 seconds. Simultaneously and for another 18 seconds a direct current proportional in size to the ma- ximum phase of the main current is fed in at the terminals I(+) and I(-). By comparing the analog signal, which is to be measured, with the main current, the accuracy of the current measurement can be determined. In this case 4 mA corresponds to 0 % and 20 mA to 125 % of the current setting.
After 24 seconds the auxi- liary contacts are switched and the feeder switch off as the result, bringing the test to an end. Response if the control supply voltage fails If the control supply voltage fails for more than 0.2 s, the output re- lays respond differently depending on the version: monostable or bistable. After a test trip a faultless relay is reset by pressing the TEST/ RESET button. If a hardware fault is detected, the device trips and cannot be reset. Self-monitoring The 3RB22/3RB23 solid-state overload relays have a self-monito- ring feature, i. e. the devices constantly monitor their own basic functions and trip if an internal fault is detected.
The particular operating state of the 3RB22/3RB23 solid-state overload relays is displayed by means of four LEDs: Green " READY " LED: A continuous green light signals that the overload relay is ready for operation. The 3RB22/3RB23 over- load relays are not ready (LED "OFF") if there is no control sup- ply voltage or if the function test was negative. Red " GND FAULT " LED: A continuous red light signals a ground fault. Red " THERMISTOR " LED: A continuous red light signals a tempe- rature-dependent trip. Red " OVERLOAD " LED: A continuous red light signals an inverse- time delayed trip; a flickering red light signals an imminent in- verse-time delayed trip (overload warning).
Display of the operating state Monostable and bistable responses of the output relays & ' ( ) * ' + , - . . + / 0 ' + ) 1 2 3 + - * . * 3 ' * ) 4 * 3 , ) ' * ' * ' 0 * 6 - * * ( ) ) * 3 . . 3 ( Control supply voltage 0 1 t monostable NC NO bistable NO NC & ' ( ) * ' + , - . . + / 0 ' + ) 1 2 3 + - * . * 3 ' * ) 4 * 3 , ) ' * ' * ' 0 * 6 - * * ( ) ) * 3 . . 3 ( 1 monostable NO bistable NO NC NC ' ) ' * ) . ) ' ' 4 3 1 4 9 0 3 6 ) * 3 . & ' ( ) * ' , - . . + / 0 ' + ) 1 2 3 + - * ) - * ( ' 2 6 ' ( ) * ' , - . . + / 0 ' + ) 1 ( - + - ) ' * , ) 2 ) * 5 3 ( ' * 2 ) * ) 4 * 3 , ) ' * 4 , 6 ' ' + 9 9 ' : NSB0_01628 & ' ( ) 6 ) ' * ' .
& ' ( ) 6 ) ' * 6 + ' , 32 Siemens · 2009 Response of the output relays in the event of Monostable 3RB22 Bistable 3RB23 Failure of the control supply voltage The device trips No change of the swit- ching state of the auxiliary contacts Return of the control supply voltage without previous trip- ping The device resets No change of the swit- ching state of the auxiliary contacts Return of the control supply voltage after previous tripping The device remains trip- ped Reset: • For overload tripping, after 3 minutes • For thermistor tripping, after the temperature has fallen 5 K below the response temperature • For ground-fault trip- ping, immediately The device remains trip- ped Reset:
• For overload tripping, after 3 minutes • For thermistor tripping, after the temperature has fallen 5 K below the response temperature • For ground-fault trip- ping, immediately