ABC-200-480-P Motortronics Electronic Motor Brake

The Motortronics ABC Series Electronic Motor Brakes are solid state DC injection brakes for stopping three- phase AC induction motors. This full-wave DC brake design offers smooth, low peak level braking for quiet, steady operation and optimal performance. Designed to handle even high inertia loads, the ABC Series eliminates costly and potentially dangerous "coast-to-stop" times. A built-in microprocessor provides system supervision that includes digital timing control for jogging and braking. The integral Operator Interface Module provides LED indication of the unit's operating status and easy adjustments for quick setup. Standard features include interlocks and mechanical brake release relays, a brake disable input and zero speed sensing with override. Installation involves simply wiring the device into the motor's starter circuit, which allows it to operate in parallel with the starter.

Incoming AC power is fed to terminals L1 and L2 directly from the line side of the motor starter terminals and is converted to DC within the ABC Series. Once the motor starter has been turned off (opened) and the residual energy in the motor has dissipated, the DC current from the ABC Series is applied (injected) to starter terminals T1 and T2 respectively. This creates a stationary magnetic field in the AC motor stator windings. The braking torque will increase in proportion to the amount of current allowed to flow. The rotor continuously attempts to pull into alignment with this stationary field. This creates braking action which brings the load to a stop faster than if it coasted to a stop. ABC Series brakes are suitable for use in most AC motor applications where coast-to-stop times are undesirable or unacceptable. The ABC Series is a current controlling brake, so various sizes of brake units can be applied to various motor sizes. Because DC injection means applying power to the AC motor after turning it "Off", motor heating (although minimal) will continue during the braking cycle and should be considered when selecting the motor. AC motor manufacturers recommend that each braking cycle over 100% FLA be considered as an additional starting cycle when calculating the starts- per-hour ratings for the selected motor. If the selected ABC Series is sized to deliver 200% of motor rated current, consider each brake cycle to be 2 start cycles for these calculations (and 300% FLA = 3 "starts" per brake). Never size any DC injection brake to exceed 400% of the motor nameplate FLA without first consulting the motor manufacturer.