Current monitoring relay Siemens SIRIUS 3RR2142-1AW30
SIRIUS 3RR2242, 3RR2142, 3RR2243 current monitoring relays
The SIRIUS 3RR2 current monitoring relays are suitable for load monitoring of motors or other loads. In two or three phases they monitor the rms value of AC currents for overshooting or undershooting of set threshold values.
Whereas apparent current monitoring is used above all in connection with the rated torque or in case of overload, the active current monitoring option can be used to observe and evaluate the load factor over a motor’s entire torque range.
The 3RR2 current monitoring relays can be integrated directly in the feeder by mounting on the 3RT2 contactor; separate wiring of the main circuit is therefore superfluous. No separate transformers are required.
For a line-oriented configuration or simultaneous use of an overload relay, terminal supports for stand-alone installation are available for separate standard rail mounting.
The basic versions with 2-phase apparent current monitoring, a CO contact output and analog adjustability provide a high level of monitoring reliability especially in the rated and overload range.
The standard versions monitor the current in three phases with selectable active current monitoring. They have additional diagnostics options such as residual-current monitoring and phase sequence monitoring, and they are also suitable for monitoring motors below the rated torque. These devices have an additional independent semiconductor output, an actual value indicator, and are digitally adjustable.
Both versions are available optionally with screw terminals or spring-loaded terminals, in each case for sizes S00 and S0. With variants of size S2 the main conducting paths always have screw terminals; the control current side can have screw or spring-loaded terminals.
In addition to the features of the standard versions, the 3RR24 monitoring relays for mounting on 3RT2 contactors for IO-Link also offer the possibility of transmitting the measured values and diagnostics data to a controller via an IO-Link. Furthermore, the devices can be parameterized on the devices themselves or via IO-Link.
For more information, see .
3RR21 and 3RR22 overview table
— Not available
Possible combinations of 3RR21/3RR22 monitoring relays with 3RT2 contactors
Article No. scheme
The Article No. scheme shows an overview of product versions for better understanding of the logic behind the article numbers. For your orders, please use the article numbers quoted in the selection and ordering data.
- Directly mountable onto 3RT2 contactors and 3RA23 reversing contactor assemblies, i.e. no additional wiring outlay in the main circuit
- Optimally coordinated with the technical characteristics of the 3RT2 contactors
- No separate current transformer required
- Versions with wide voltage supply range
- Variably adjustable to overshoot, undershoot or range monitoring
- Freely configurable delay times and RESET response
- Display of ACTUAL value and status messages
- All versions with removable control current terminals
- All versions with screw terminals or spring-loaded terminals
- Simple determination of the threshold values through direct reference to actually measured values for setpoint loading
- Range monitoring and selectable active current measurement mean that only one device for monitoring a motor is required along the entire torque curve.
- In addition to current monitoring it is also possible to monitor for broken cables, phase failure, phase sequence, residual current and motor blocking.
- Monitoring of current overshoot and undershoot
- Monitoring of broken conductors
- Monitoring of no-load operation and load shedding, e.g. in the event of a torn V-belt or no-load operation of a pump
- Monitoring of overload, e.g. on conveyor belts or cranes due to a high load
- Monitoring of functionality of electrical loads such as heaters
- Monitoring of incorrect phase sequences on mobile equipment such as compressors or cranes
- Monitoring of high-impedance faults to ground, e. g. caused by damaged insulation or moisture
Function diagrams of 3RR214.-.A.30 basic variants, analogically adjustable
Closed-circuit principle upon application of the control supply voltage
Function diagrams of 3RR224.-.F.30 standard versions, digitally adjustable
With the closed-circuit principle selected upon application of the control supply voltage
Current undershoot with residual-current monitoring
Phase sequence monitoring
Monitoring relay, can be mounted to Contactor 3RT2, Size S0 basic, analog adjustment Apparent current monitoring 4…40 A, 50…60 Hz, 2-phase Supply 24-240 V AC/DC 1 change-over contact Monitoring for Current overshoot and undershoot Phase failure, Cable break with or without fault buffer ON delay 0-60 s Noise pulse suppression 0-30 s Switching hysteresis 6% Screw connection system