Product Overview for the 3RW4435-6BC44 Soft Starter

The 3RW4435-6BC44 is a SIRIUS soft starter from Siemens. Firstly, this device is designed for high feature soft starting applications. Specifically, it includes an integrated bridging contact system and thyristors for reliable operation. In addition, the 3RW4435-6BC44 supports both standard and inside-delta circuit configurations. Consequently, this soft starter delivers 134A at 400V for 75kW motors in standard mode. Moreover, inside-delta circuit operation provides 232A for 132kW motors at the same voltage. Therefore, the 3RW4435-6BC44 offers exceptional flexibility for various motor starting requirements.

Circuit Configurations and Power Ratings

Standard Circuit Operation
The 3RW4435-6BC44 delivers impressive power in standard circuit mode. Firstly, the operating current is 134A at 40°C ambient temperature. In addition, the emitted mechanical power reaches 75kW at 400V. Specifically, the motor power rating is 37kW at 230V for lower voltage systems. Consequently, standard circuit mode suits most conventional motor starting applications.

Inside-Delta Circuit Operation
The 3RW4435-6BC44 provides higher current in inside-delta mode. Firstly, the operating current reaches 232A at 40°C, which is significantly higher than standard mode. In addition, the emitted mechanical power achieves 132kW at 400V. Specifically, the motor power rating is 75kW at 230V for this configuration. Consequently, inside-delta connection allows starting larger motors with the same soft starter unit.

Temperature Derating Performance
The 3RW4435-6BC44 maintains high output across elevated temperatures. Firstly, at 50°C, the operating current is 117A in standard mode and 203A in inside-delta mode. In addition, at 60°C, the current ratings are 100A and 173A respectively. Therefore, the 3RW4435-6BC44 performs reliably even in warm industrial environments.

Protection and Control Features

Comprehensive Motor Protection
The 3RW4435-6BC44 includes multiple integrated protection functions. Firstly, intrinsic device protection guards the soft starter itself against faults. In addition, motor overload protection prevents damage to connected motors from excessive current. The device also supports evaluation of thermal resistor motor protection for accurate temperature monitoring. Consequently, the 3RW4435-6BC44 provides complete motor starting and protection in one compact unit.

Adjustable Current Limitation
The 3RW4435-6BC44 features flexible current adjustment capabilities. Firstly, the minimum adjustable rated current is 26A for smaller motor applications. In addition, the device operates continuously at 115% of rated current at 40°C without tripping. Specifically, this adjustment range covers various motor sizes from 26A up to the maximum rating. Consequently, the 3RW4435-6BC44 can be tuned precisely to your motor's specific characteristics.

External Reset Capability
The 3RW4435-6BC44 supports remote reset functionality. Firstly, this feature allows operators to clear faults from a control room location. In addition, it reduces downtime by eliminating the need for local manual resets. Specifically, the external reset input connects to a push button or PLC output. Therefore, the 3RW4435-6BC44 integrates easily into automated control systems.

Integrated Bridging System

Bypass Contactor Integration
The 3RW4435-6BC44 includes a built-in bridging contact system. Firstly, this system automatically bypasses the thyristors after successful motor start-up. In addition, it significantly reduces power loss and heat generation during continuous running operation. Specifically, the typical active power loss is only 76W at full operating current. Consequently, the 3RW4435-6BC44 operates efficiently without requiring external bypass contactors.

Energy Efficiency Benefits
The integrated bridging system delivers measurable energy savings. Firstly, thyristor losses are eliminated during steady-state running. In addition, the reduced heat dissipation lowers cabinet cooling requirements. Therefore, the 3RW4435-6BC44 reduces overall system operating costs compared to non-bypassed soft starters.

Electrical Specifications

Voltage and Frequency Ratings
The 3RW4435-6BC44 operates across broad electrical ranges. Firstly, the operating voltage range is 200 to 460V AC for both circuit configurations. In addition, the operating frequency range is 50 to 60 Hz with ±10% tolerance. Specifically, the control supply voltage is 230V AC at both 50 Hz and 60 Hz. The voltage tolerance is -15% to +10% for reliable operation. Therefore, the 3RW4435-6BC44 works in many global electrical systems without modification.

Current Ratings and Limits
The 3RW4435-6BC44 handles substantial motor currents safely. Firstly, the minimum load requirement is 8% of motor rated current for proper operation. In addition, the adjustable rated current range starts at 26A for smaller motors. Specifically, the continuous operating current capacity is 115% of Ie at 40°C. Consequently, the 3RW4435-6BC44 provides ample overload margin for demanding applications.

UL/CSA Horsepower Ratings
The 3RW4435-6BC44 carries full UL/CSA certifications for North America. Firstly, in standard circuit mode at 220/230V, the rating is 40 hp. At 460/480V in standard mode, the rating reaches 75 hp. In inside-delta mode at 460/480V, the rating is an impressive 150 hp. Therefore, the 3RW4435-6BC44 is suitable for installations requiring UL/CSA approval.

Mechanical Specifications

Physical Dimensions and Weight
The 3RW4435-6BC44 has a robust industrial enclosure. Firstly, the width is 170 mm for standard cabinet mounting. In addition, the height is 200 mm and the depth is 270 mm. Specifically, the protection class is IP00 for installation inside control cabinets. The device mounts using screw fixing for secure attachment. Therefore, the 3RW4435-6BC44 occupies moderate panel space for its power rating.

Clearance Requirements
Proper clearance around the 3RW4435-6BC44 ensures adequate cooling. Firstly, maintain 100 mm clearance above the device for hot air exhaust. In addition, keep 5 mm clearance on both sides for airflow. Specifically, the required clearance below the device is 75 mm. Consequently, these spacing guidelines prevent overheating and ensure reliable long-term operation.

Mounting Flexibility
The 3RW4435-6BC44 offers flexible mounting orientations. Firstly, the device can be rotated ±90° on a vertical mounting plane. In addition, it can be tilted ±22.5° forward and backward from vertical. Specifically, this flexibility accommodates various cabinet layouts and space constraints. Therefore, installation is possible even in non-standard control panels.

Electrical Connections

Main Circuit Connections
The 3RW4435-6BC44 uses busbar connections for the main power circuit. Firstly, stranded conductors from 16 to 70 mm² are supported for flexible wiring. In addition, the device has three poles for three-phase motor connections. Specifically, front clamping, back clamping, or both clamping points can be used. For DIN cable lugs, conductors from 16 to 95 mm² are accepted. Therefore, the 3RW4435-6BC44 accommodates various wiring preferences and practices.

Auxiliary Contact Configuration
The 3RW4435-6BC44 includes four auxiliary contacts for status signaling. Firstly, three NO (normally open) contacts are provided for run or fault indication. In addition, one changeover contact is included for flexible control wiring. Specifically, no NC (normally closed) contacts are present on this model. The UL contact rating is B300 / R300 for reliable performance. Consequently, the 3RW4435-6BC44 integrates easily with external control circuits.

Auxiliary Circuit Wiring
The auxiliary circuits use screw-type terminals for secure connections. Firstly, solid conductors from 2x (0.5 to 2.5 mm²) are accepted directly. In addition, finely stranded conductors with end processing from 2x (0.5 to 1.5 mm²) are supported. For AWG conductors, sizes 2x (20 to 14) are compatible. Therefore, the 3RW4435-6BC44 accepts common industrial control wiring.

Environmental Specifications

Temperature and Altitude Ratings
The 3RW4435-6BC44 operates in demanding environmental conditions. Firstly, the maximum operating temperature is 60°C with appropriate derating. In addition, the storage temperature range is -25°C to +80°C for warehouse conditions. Specifically, derating begins at 40°C ambient temperature. The maximum installation altitude is 5,000 meters above sea level. Therefore, the 3RW4435-6BC44 suits installations in high-temperature and high-altitude locations.

Cable Length Limitations
The 3RW4435-6BC44 supports long motor cable runs. Firstly, the maximum cable length between soft starter and motor is 500 meters. In addition, longer cables may require output filters for reduced reflected wave voltage. Therefore, consult Siemens application guidelines for installations approaching this limit.

Installation Guide for the 3RW4435-6BC44

Follow these steps for a proper installation of the 3RW4435-6BC44.

Step 1: Mounting Location Preparation
Firstly, ensure the mounting surface is vertical, flat, and stable. Then, maintain 100 mm clearance above the 3RW4435-6BC44 for cooling airflow. In addition, keep 5 mm clearance on both sides and 75 mm clearance below. Consequently, proper heat dissipation will be maintained during full load operation.

Step 2: Device Mounting
After that, secure the 3RW4435-6BC44 using screw fixing through the mounting holes. The device can be rotated ±90° on a vertical mounting plane if needed. It can also be tilted ±22.5° forward and backward for flexible installation. Then, tighten all mounting screws to the recommended torque specifications.

Step 3: Main Circuit Wiring
Then, connect the main power cables to the 3RW4435-6BC44 using busbar connections. Use stranded conductors from 16 to 70 mm² for optimal current-carrying capacity. For DIN cable lugs, use 16 to 95 mm² finely stranded conductors instead. Consequently, the main circuit will handle the full rated current safely.

Step 4: Control Circuit Wiring
Furthermore, connect the 230V AC control supply voltage to the designated terminals. The 3RW4435-6BC44 accepts screw-type terminals for all auxiliary circuits. Connect external reset wiring if remote fault clearing capability is needed. Then, connect thermal resistor motor protection leads if motor temperature monitoring is required.

Step 5: Configuration and Testing
Finally, set the adjustable rated current between 26A and the motor's full load current value. Select either standard circuit or inside-delta circuit mode based on your motor configuration. Then, apply power and test the 3RW4435-6BC44 with your connected motor. Verify smooth acceleration without excessive current draw or unexpected tripping.

Packaging List for the 3RW4435-6BC44

• 3RW4435-6BC44 SIRIUS soft starter (1 unit)

• Mounting hardware and screws (1 set)

• Product documentation and quick start guide (1 copy)

Frequently Asked Questions (FAQs) About the 3RW4435-6BC44

Q1: What is the difference between standard and inside-delta circuit for the 3RW4435-6BC44?

In standard circuit, the 3RW4435-6BC44 delivers 134A for 75kW motors at 400V. In inside-delta circuit, it delivers 232A for 132kW motors at the same voltage. Therefore, inside-delta connection allows starting larger motors with the same soft starter unit.

Q2: What protection functions does the 3RW4435-6BC44 include?

The 3RW4435-6BC44 includes intrinsic device protection and motor overload protection. In addition, it supports thermal resistor motor protection evaluation for accurate temperature monitoring. The device also features adjustable current limitation and external reset capability. Consequently, separate external overload relays are not required.

Q3: What is the maximum operating temperature for this soft starter?

The 3RW4435-6BC44 operates at full rating up to 40°C ambient temperature. From 40°C to 60°C, current derating applies as shown in the specifications table. Therefore, ensure adequate cabinet cooling for high-temperature installations.

Q4: What are the clearance requirements around the 3RW4435-6BC44?

The 3RW4435-6BC44 requires 100 mm clearance above the device for hot air exhaust. In addition, 5 mm clearance is needed on both sides for airflow. The required clearance below the device is 75 mm. Consequently, these spacing guidelines ensure proper cooling and reliable operation.

Q5: Does the 3RW4435-6BC44 have UL/CSA certification?

Yes, it does. The 3RW4435-6BC44 carries full UL/CSA ratings for both standard and inside-delta circuits. The UL horsepower ratings range from 40 hp to 150 hp depending on voltage and circuit configuration. Therefore, this soft starter is suitable for North American installations requiring formal safety approvals.