Product Description
Benshaw RB2-1-S-302A-15C Open-Chassis Soft Starter — 302A, Integral Bypass, MX2
The Benshaw RB2-1-S-302A-15C is a 302-amp low-voltage open-chassis soft starter with integral bypass and Benshaw MX2 control technology. It is rated for standard-duty starting at 250 HP @ 460 V and 125 HP @ 230 V, and combines Benshaw's rugged, compact RB-series integral-bypass power section with the MX2 platform's programmable starting modes, metering, and motor protection. The integral bypass contactors carry the motor current once the motor is up to speed, allowing efficient operation without external cooling fans.
- Part Number: RB2-1-S-302A-15C
- Brand: Benshaw
- Type: Open-chassis low-voltage soft starter, integral bypass
- Control Technology: Benshaw MX2
- Amp Rating: 302 A
- Horsepower: 250 HP @ 460 V / 125 HP @ 230 V (standard duty)
- Duty: Standard duty
- Style: Open chassis
- Weight: 51 lbs
- Dimensions: 24 × 13 × 11 in (H × W × D)
- Warranty: Benshaw 3-year parts warranty
- Availability: Ships in 24 hours — see stock status on this page
Ratings & Specifications
| Specification | Value |
|---|---|
| Amp Rating | 302 A |
| Horsepower | 250 HP @ 460 V | 125 HP @ 230 V |
| Duty Rating | Standard duty — 350% for 30 seconds, 115% continuous |
| Control Technology | Benshaw MX2 |
| Style | Open chassis, integral bypass |
| Weight | 51 lbs |
| Dimensions (H × W × D) | 24 × 13 × 11 in |
| Warranty | Benshaw 3-year parts warranty |
Understanding the Part Number
Benshaw RediStart part numbers are built from a model code that identifies the chassis, control, duty, and rating.
| Segment | Meaning |
|---|---|
| RB2 | RediStart integral-bypass chassis with MX2 control |
| S | Standard duty |
| 302A | 302-amp rating |
| C | Open chassis construction |
MX2 Starting Modes & Motor Protection
The included MX2 control package provides multiple user-selectable starting modes — voltage ramp, current ramp, torque ramp (TruTorque), and power ramp — giving flexibility across a wide range of applications. Setup and commissioning are handled through the MX2 Quick Start Menu. On the protection side, the MX2 platform provides motor thermal overload, phase reversal, phase loss, overcurrent, and undercurrent protection, among other protective functions, to help safeguard the connected motor.
Key Advantages of the RB Series
- Compact integral-bypass design: Integral bypass contactors carry current at full speed, eliminating the need for external cooling fans.
- Modular power stack: Modular assembly simplifies maintenance and service.
- Communications: Modbus standard, with other Fieldbus protocols optional.
- Flexible starting: Multiple starting ramps and dual-ramp capability for loaded and unloaded applications.
- Integrated metering & diagnostics: Built-in metering and motor protection reduce the need for external devices.
Frequently Asked Questions
What is the Benshaw RB2-1-S-302A-15C?
It is a 302-amp low-voltage open-chassis soft starter with integral bypass and Benshaw MX2 control technology, rated for standard-duty starting at 250 HP @ 460 V and 125 HP @ 230 V. It is part of Benshaw's RediStart RB2 series.
What horsepower and amp rating does it support?
The RB2-1-S-302A-15C is rated at 302 amps, supporting 250 HP at 460 V and 125 HP at 230 V in standard-duty service. Because horsepower depends on supply voltage and duty class, confirm the rating against your motor's nameplate before ordering.
What does "integral bypass" mean on this soft starter?
Integral bypass means the starter includes built-in bypass contactors that carry the motor current once the motor reaches full speed. This removes the SCRs from the current path during running, reduces heat, and eliminates the need for external cooling fans — giving a more compact, efficient package.
What is the difference between the RB2 and RB3 versions?
The RB2 uses Benshaw's MX2 control technology, while the RB3 uses the next-generation MX3 platform, which adds features such as a real-time clock, expanded programming, an event log, and RTD support. The RB3-1-S-302A-15C is the MX3 equivalent of this starter. Contact Kent Electrical Supply if you need help choosing between them.
What starting modes does the MX2 control offer?
The MX2 control package offers multiple user-selectable starting modes, including voltage ramp, current ramp, torque ramp (TruTorque), and power ramp, along with dual-ramp capability for loaded and unloaded applications. Setup is handled through the MX2 Quick Start Menu.
Is the RB2-1-S-302A-15C in stock, and what is the warranty?
Current stock status is shown on this page; when not in stock, this starter typically ships within 24 hours from Kent Electrical Supply in Emmaus, PA. It carries Benshaw's 3-year parts warranty. For lead time, quantity pricing, or application help, call 800.222.5129 or text an RFQ to 484.425.0652.
