Emerson Network Power has introduced a breakthrough in paralleling and controlling multiple electrical bus on-site power systems.

The new ASCO® Multiple Bus Load and Generator Control software makes it possible for a single programmable logic controller (PLC) in ASCO Generator Paralleling Switchgear to reliably operate up to eight independent multiple buses simultaneously with full, feature-rich functionality. In addition, when multiple buses are part of a 3 phase, complex  tie breaker connected ring, the ASCO Multiple Bus Load and Generator Control software offers the flexibility to operate any combination of the buses as a single system, or separately when they're disconnected, again with full functionality.

"So far as we know, ASCO Multiple Bus Load and Generator Control software is the first of its kind in power switching and control," said William Dustman, manager of ASCO Power Control Systems at Emerson Network Power's Welcome, NC plant. It reflects ASCO's ability to program the most complex software and represents the latest in a long line of ASCO technology innovations.

"Before developing this software, operating multiple buses meant sacrificing full operational functionality until all bus tie breakers closed, creating  a common bus," Dustman said. Full functionality encompasses automatic gen-set startup, block loading, load priority pass-along, under frequency load shed, bus optimization, bus overload, load demand, load control, load hand-off auto, and no-load system test.

Sacrificing such functionalities as block loading, bus optimization, load shed bypass, and load demand limited control flexibility, but no more. All those functionalities now occur independently on isolated buses and simultaneously on buses with tie breakers.    

In fact, ASCO Multiple Bus Load and Generator Control software enhances operational flexibility. Hospitals and other mission critical facilities, such as data centers, often want to power more than priority one loads. But closing and opening tie breakers for multiple loads on multiple buses to connect with multiple gen-sets could be problematic. Now, they can manage that process automatically, even if they have two entirely separate systems and want to manage them with one PLC. In addition, servicing a tie breaker bus is easier since gen-sets and loads can be routed to other buses. These capabilities improve overall system reliability.

Dustman compared the software's capabilities to replacing a single core 'brain' of a master PLC program with eight core 'brains.' "It's like replacing one person with eight," he said.

ASCO Multiple Bus Load and Generator Control software drives a PLC in the Master section of the lineup. It controls up to 16 gen-sets and 128 loads spread across up to eight buses. It is suitable for both standard and mission-critical applications, and low- and medium voltage systems.

ASCO Multiple Bus Load and Generator Control software already has been integrated in ASCO Generator Paralleling Switchgear for a public safety and answering center. Two buses are designed to operate independently, unless an on-site gen-set fails on one of them, In that event, the PLC is programmed to connect the two buses so a 'swing' gen-set on the other bus can power the load.