Benshaw RB3 Series Open Chassis Soft Starters combine our advanced MX3 motor control technology with a rugged, compact, integral bypass RB series power section.
The RB3 Open Chassis Soft Starter is a rugged compact, simple to use soft starter with built-in motor protection that gives you greater control in starting and stopping of three phase motors. The integral bypass contactor reduces the watt loss of the soft starter allowing RB3 Series Open Chassis Soft Starters to be mounted in non-vented enclosures.
Benshaw’s MX3 control technology (included with RB3 Series Open Chassis Soft Starters) provides advanced motor protection with adjustable overload setting and available RTD monitoring … eliminating the need for a third party motor protection relay. A real time clock with an event recorder (up to 99 events) is also included with the MX3 control technology, along with adjustable motor ramp profiles that can be tailored to the motor load (allowing for a smooth ramp of the motor) and adjustable voltage control deceleration suitable for use in pumping applications.
The RB power section is a rugged, heavy duty solid state starter section designed with integral bypass contactors for a compact, efficient profile. The modular design includes separate poles for each phase for ease of maintenance.
Benshaw’s RB3 Series Open Chassis Soft Starters can be programmed using the provided remote mount LCD keypad or Modbus register mapping.
Key Features
Benshaw’s MX3 control technology provides all MX2 features, plus:
- 8 user-configurable inputs
- 2 fixed inputs for start and bypass confirm
- 6 user-configurable relay outputs
- 1 fixed output for bypass control
- Real-time clock
- Motor PTC input
- Zero sequence ground fault
- RTD module support
- Event log (99 events)
- Start per hour limiter
- Back spin timer
- Time between starts limiter
- Zero speed switch input
- Power outage ride through (PORT)
- Power factor trip
- Patented CYCLO control (0–40% speed)
MX3 Control Highlights
Benshaw’s next generation MX3 technology propels low voltage motor control to even greater levels of performance and functionality. With its real-time clock, enhanced programming capabilities, ease-of-use and a unique, flexible architecture — Benshaw’s MX3 controller delivers advanced motor control and protection with all of the rugged, dependable performance you’ve come to expect from the world leader in advanced controls and drives.
MX3 controllers, power components, software and sensors are all designed, built and tested to perform as an integrated control system, eliminating the coordination and performance problems inherent in other forms of reduced voltage starting. With more built-in features, more configurable options, greater expandability and a broader communications capability than any other motor control on the market, Benshaw’s next generation MX3 technology will shorten your commissioning times, improve motor performance and protection, enhance diagnostic capability and streamline electrical system monitoring and maintenance tasks.
Motor Protection Features
- ANSI 14 – Speed switch and tachometer trip
- ANSI 19 – Reduced voltage start
- ANSI 27 / 59 – Adjustable over/under voltage protection (Off or 1 to 40%, time 0.1 to 90 seconds in 0.1 second intervals, independent over and under voltage levels)
- ANSI 37 – Undercurrent detection (Off or 5 to 100% and time 0.1 to 90.0 seconds in 0.1 second intervals)
- ANSI 38 – Bearing RTD / Other RTD / Open RTD alarm
- ANSI 46 – Current imbalance detection (Off or 5 to 40%)
- ANSI 47 – Phase rotation (selectable ABC, CBA, Insensitive, or Single Phase)
- ANSI 48 – Adjustable up-to-speed / stall timer (1 to 900 seconds in 1 second intervals)
- ANSI 49 – Status RTD
- ANSI 50 – Instantaneous electronic overcurrent trip
- ANSI 51 – Electronic motor overload (Off, class 1 to 40, separate starting and running curves available)
- ANSI 51 – Overcurrent detection (Off or 50 to 800% and time 0.1 to 90.0 seconds in 0.1 second intervals)
- ANSI 51G – Residual ground fault detection (Off or 5 to 100% of motor FLA) / zero sequence ground fault detection (Off, 0.1 – 25 amps)
- ANSI 66 – Starts/hour and time between starts / restart block (backspin timer)
- ANSI 74 – Alarm relay output available
- ANSI 81 – Over/under frequency
- ANSI 86 – Overload lockout
- Single phase protection
- Shorted SCR detection
- Mechanical jam
Click here to learn more about Benshaw RB3 Series Open Chassis Soft Starters and accessories.
