Overview
The KB Electronics KBMG Series are ultracompact, full-wave regenerative drives capable of operating DC PM or shunt motors in a bidirectional mode. Their 4-quadrant operation provides forward and reverse torque in both speed directions, allowing the control to maintain constant speed with overhauling loads while providing rapid reversing and controlled braking. Because of its excellent controllability and response time, the KBMG can replace servos in many applications.
The range covers two models: the KBMG-21D, suited to smaller fractional horsepower loads from 1/50 to 1/6 HP, and the KBMG-212D, which covers 1/50 to 1 HP at 115 VAC and 1/25 to 2 HP at 230 VAC when fitted with the optional Auxiliary Heat Sink. Both models operate on either 115 or 208/230 VAC via jumper selection.
Key Features
The control is factory set for armature feedback, providing up to 1% load regulation over a motor base speed of 50:1. Tach-generator feedback is also provided for superior load regulation where required, and a simple jumper setting converts the KBMG to a torque control, in which motor torque rather than motor speed is controlled.
An important feature of the drive is the factory-calibrated, built-in, selectable motor current jumper, which eliminates the need to recalibrate IR Comp and Current Limit for most applications. The control contains an Enable function that can be used to start and stop the motor electronically via a contact closure, and through a jumper selection, the motor can be controlled to rapidly “regenerate to stop” or to “coast to stop.”
KB’s exclusive Auto Inhibit circuit provides safe, smooth starting even during rapid cycling of the AC line, while the Overspeed Protect Circuit prevents failure of the power bridge in extreme overhauling conditions. Reliability is further enhanced with a high speed current limit circuit and MOV transient protection. LEDs for power on and motor overload are provided for diagnostics, and a rugged extruded aluminium heat sink ensures enhanced heat transfer for a higher control rating while keeping SCRs running cooler. The KBMG includes a finger-safe cover to meet the IP-20 standard.
Power connections are made via quick connect terminals, and signal input connections via a removable barrier terminal block. A 5k remote potentiometer and full operating instructions are supplied with the control.
Accessories
The optional Auxiliary Heat Sink (P/N 9861) increases the control rating to 1 HP at 90 VDC and 2 HP at 180 VDC. The SIMG Bipolar Signal Isolator (P/N 8832) allows a non-isolated signal source to be used, and the Multi Speed Board (P/N 8833) provides discrete preset speeds which can be controlled from a PLC. A DIN Rail Mounting Kit (P/N 9995) is also available to convert the control to standard DIN rail mounting.
Common Applications
The KBMG is used across applications requiring precise bidirectional speed or torque control, including conveyors, indexers, feeders, positioners, textile equipment, packaging machinery, web control and converting machinery, particularly where overhauling loads, rapid reversing or controlled braking are part of the application requirement.
Selection Considerations
Selecting between the KBMG-21D and KBMG-212D depends on the required horsepower and current rating — the KBMG-21D suits smaller fractional loads, while the KBMG-212D covers a wider range up to 2 HP with the optional Auxiliary Heat Sink fitted. Applications requiring tighter load regulation should consider tach-generator feedback, and applications needing torque rather than speed control can use the jumper selectable torque mode. Where a non-isolated signal source must be used, the SIMG Bipolar Signal Isolator should be specified.
Motordrives Australia can help confirm the right KBMG model and any required accessories based on your motor’s horsepower, voltage and bidirectional control requirements.
Support And Enquiries
Motordrives Australia supplies and supports the KB Electronics KBMG Series for Australian machine builders and maintenance teams. For assistance with model selection, jumper configuration or accessory selection, contact our team with your motor’s horsepower, voltage and application details.
