On the Siemens Sirius 3RW44 softstarter

The Siemens SIRIUS 3RW44 soft starter devices are designed to control the acceleration and braking modes of asynchronous electric motors in the power range from 15 to 710 kW, when switched on inside the "triangle" up to 1200 kW.
The use of Siemens SCP allows you to optimize and control the transient process and ensure a high degree of protection of the electric drive during operation. Modern algorithms for torque control and current limitation of an asynchronous electric motor do not allow parasitic phenomena in electrical networks, mechanical nodes, and hydrodynamic systems.
A wide range of functions and attractive cost make SIRIUS 3RW44 control devices an alternative option for using a frequency converter, leading to significant cost savings, unification of the formation of switchgear and ease of maintenance of the machine park.
The SIRIUS 3RW44 SCP supports the Profibus DP control protocol.
Technical characteristics of Siemens Sirius 3RW44 series soft starters
Rated power: 15 – 710 kW (up to 1200 kW when connected inside the "triangle");
Rated current: 29 – 1214 A (up to 2100 A when connected inside the "triangle");
Rated operating voltage: 220-690 V AC;
Voltage of the electronics supply: 24 V DC /115 V AC /230 V AC;
Acceleration/stop voltage level: 20...100%;
Acceleration and run-out time: 1...360c;
Start/stop time: 20...100%;
Torque limit: 20...200 s;
Line voltage change time: 1...360 s;
Temperature range: 0...+60°C;
Degree of protection: IP00.
A typical scheme for including a softstarter in the power supply and control circuit of an electric motor

For the entire list of possible options for including soft–start devices in the power supply and control circuit of an asynchronous electric motor, see the manual on page 9-1.
Built-in controls and options
Built-in information text display with Russian language support and push-button control module;
Programmable device control inputs 4 pcs. ("Manual on-site control", "Emergency start", "Creeping speed", "Quick stop", for more information, see the manual on pages 5-29);
Indicator of measured values, states and errors;
Programmable status relays (1NO+1NZ contacts) 3 pcs. ("Power on", "Ready to start", "Operation /Bypass", "Profibus bus error", for more information, see the manual on page 5-30);
Status relay 1 pc. ("General error");
Option – external display and control module;
Bypass/shunt contactor built into the device housing;
Option - protective coating of printed circuit boards for use in aggressive environments;
Analog input for connecting a PTC temperature sensor from an electric motor (thermal protection);
Soft Starter ES software for device parameterization;
Screw or spring terminals for connection of power and signal circuits;
The option is to connect to the Profibus industrial bus.
Built-in control, management and protection functions of the electric drive
The ability of the device to work when connected to a line or inside a "triangle";
Soft start and stop function of the electric motor;
Push mode for starting jammed and inert mechanisms;
The function of limiting the starting current of the electric motor;
The function of regulating the torque of the electric motor;
Direct current braking function (DC braking);
The "Combined braking" function;
The "Heavy start" and "Very heavy start" function;
Pump equipment stop control function;
"Creeping speed" function for forward and reverse switching;
The function of "Heating the electric motor";
The function of monitoring the maximum /minimum values of the operating parameters;
The function of protection against network voltage asymmetry;
Error and warning log;
The "Remote reset" function;
Thermal protection of the device thyristors;
The electronic protection function of the electric motor (based on measuring the current flowing through the electric motor during operation);
Thermistor protection of the electric motor (measuring the temperature of the electric motor windings using PTC sensors);
The "Standby recovery time" function (the time interval required to restore the normal temperature of the device /electric motor after the thermal protection is triggered).
Operating modes of Siemens Sirius 3RW44 soft starters and applications
Normal start-up conditions (Class 10): maximum start-up time is 10 seconds, starting current is 300%, 5 starts/hour;
Application: hydraulic pumps, presses, belt conveyors, roller conveyors, screw conveyors, escalators, reciprocating compressors, screw compressors, low-capacity fans, centrifugal fans, drives of auxiliary mechanisms.
Severe start-up conditions (Class 20): maximum start-up time is 10 seconds, starting current is 300%, 5 starts/hour;
Application: agitators, extruders, lathes, mills.
Very difficult start-up conditions (Class 30): maximum start-up time is 60 seconds, starting current is 350%, 1 start/hour;
Application: high-performance fans, circular saws, band saws, centrifuges, mills,
crushers.
Recommended parameters of Siemens soft starters for various applications

type of equipment	U start /Un,	T start, with	I limit /In	T stop, with	mode/class
Pumps	40	10	3 – 4	10	10
Hydraulic pumps	40	10	3 – 4	0	10
The press	40	10	5	0	10
Belt conveyors	70	10	5	5	10
Roller shutters	60	10	5	5	10
Screw conveyors	50	10	5	5	10
Escalators	60	10	4	0	10
Reciprocating compressors	40	10	4	0	10
Screw compressors	50	10	4	10	10
Standard fans	40	10	4	10	10
Centrifugal blowers	40	10	4	10	10
Auxiliary drives	40	10	4	10	10
Stirrers, mixers	40	30	3 – 4	10	20
Extruders, TPA	70	10	5	10	20
Lathes	40	30	3 – 4	10	20
Shredders	40	30	3 – 4	10	20
Large fans	40	60	3 – 4	10	30
Circular saws	40	60	3 – 4	10	30
Band saws	40	60	3 – 4	10	30
Centrifuges	40	60	3 – 4	10	30
Mills	40	60	3 – 4	10	30
Crushers	40	60	3 – 4	10	30

Un is the rated voltage of the electric motor, In is the rated current of the electric motor, U start is the value of the starting voltage, I limit is the value of the starting current limit, T start is the acceleration time, T stop is the braking time.
Designation of the registered number for the Siemens Sirius 3RW44 series SCP

3RW	44	22	-	6	B	C	4	4
I	II	III		IV	V	IV	VII	VIII

I – name of the device of the semiconductor motor control device;
II – model of the Siemens soft starter;
III – Rated operating power and rated operating current

parameter III	Pn, kW	In, And	parameter III	Pn, kW	In, And
22	15	29	45	160	323
23	18,5	36	46	200	356
24	22	47	47	250	432
25	30	57	53	315	551
26	37	77	54	355	615
27	45	93	55	400	693
34	55	113	56	450	780
35	75	134	57	500	880
36	90	162	58	560	970
43	110	203	65	630	1076
44	132	250	66	710	1214

Pn is the rated power, In is the rated current.

IV – connection type: 1 – threaded connection, 2 – conductive connection of the power circuit /spring connection of the auxiliary circuit, 3 – threaded connection of the power circuit /spring connection of the auxiliary circuit, 6 – conductive connection of the power circuit /screw connection of the auxiliary circuit;
V – special function (B – bypass/bypass contactor);
VI – the number of adjustable phases (C – all three phases are adjustable);
VII – rated control voltage Us: 3 – 115 V AC, 4 – 230 V AC;
VIII – rated operating voltage Ue: 4 – 200...460 V, 5 – 400...600 V, 6 – 400...690V.
Nominal characteristics of Siemens soft starter devices of the Sirius 3RW44 series
Operating voltage 200...460V, control voltage 230V AC, normal start-up, Class 10, line connection

Order No. (screw.)	order No. (springs)	Pn, kW (at 230V)	Pn, kW (at 400V)	In, And
3RW4422-1BC44	3RW4422-3BC44	5,5	15	29
3RW4423-1BC44	3RW4423-3BC44	7,5	18,5	36
3RW4424-1BC44	3RW4424-3BC44	11	22	47
3RW4425-1BC44	3RW4425-3BC44	15	30	57
3RW4426-1BC44	3RW4426-3BC44	18,5	37	77
3RW4427-1BC44	3RW4427-3BC44	22	45	93
3RW4434-6BC44	3RW4434-2BC44	30	55	113
3RW4435-6BC44	3RW4435-2BC44	37	75	134
3RW4436-6BC44	3RW4436-2BC44	45	90	162
3RW4443-6BC44	3RW4443-2BC44	55	110	203
3RW4444-6BC44	3RW4444-2BC44	75	132	250
3RW4445-6BC44	3RW4445-2BC44	90	160	313
3RW4446-6BC44	3RW4446-2BC44	110	200	356
3RW4447-6BC44	3RW4447-2BC44	132	250	432
3RW4453-6BC44	3RW4453-2BC44	160	315	551
3RW4454-6BC44	3RW4454-2BC44	200	355	615
3RW4455-6BC44	3RW4455-2BC44	200	400	693
3RW4456-6BC44	3RW4456-2BC44	250	450	780
3RW4457-6BC44	3RW4457-2BC44	250	500	880
3RW4458-6BC44	3RW4458-2BC44	315	560	970
3RW4465-6BC44	3RW4465-2BC44	355	630	1076
3RW4466-6BC44	3RW4466-2BC44	400	710	1214

Pn is the rated power of the electric motor, In is the maximum rated operating current of the SCP

Operating voltage 400...600V, control voltage 230V AC, normal start-up, Class 10, line connection