Allen-Bradley 150-A135NBDB Product Description

Description

Application Scenarios

In a municipal water treatment facility serving a population of over 500,000 residents, a 75 HP raw water intake pump operates on a 480V AC supply and starts multiple times daily to maintain reservoir levels. The original direct-on-line (DOL) starter caused severe water hammer during each start—the sudden acceleration of the water column generated pressure surges that stressed pipe joints and valves, while the high inrush current (approximately 6-8 times full load amperes) repeatedly tripped upstream protection devices.

The maintenance team installed a 150-A135NBDB intelligent motor controller with the pump control option enabled. During each start, the controller gradually ramps the applied voltage over a configurable period, allowing the pump impeller to accelerate the water column smoothly rather than shock-loading the piping system. Once the motor reaches near-rated speed, the 150-A135NBDB internal bypass contactor closes, bypassing the SCRs and carrying full run current through a low-resistance mechanical path. This eliminates the continuous heat generation that would otherwise require oversized heatsinks and cabinet ventilation. The pump control stop profile similarly decelerates the motor gradually, preventing the reverse flow surge that causes destructive water hammer. After the retrofit, the facility eliminated pipe joint failures, reduced maintenance costs by an estimated 40%, and extended the pump mechanical seal life from an average of 14 months to over 3 years.

Parameters