ABB'S FIREMAN'S OVERRIDECustomers expect more of ABB, but they’re unlikely to expect a drive, in the event of a fire, to change its programming to allow people to safely evacuate the building. With its fireman’s override, the ACH580 series of drives does exactly that. Turning the fans it controls into smoke extraction units, the fireman’s override pulls smoke from the building, maintaining escape routes. The drive ignores system faults, warnings, internal & external commands to deliver a ‘run at all costs operation’ until either destruction….or a fire condition signal reset. Attempts at a manual reset are ignored. This ensures that the drive remains available & operational throughout the emergency. In normal circumstances the trips & warnings it would experience during a fire would cause it to shut down.The mode is triggered by a key at the fireman’s control station. It tells the building’s fire alarm system to communicate with the drive, commanding it to enter fire mode and ignore all other instructions. The drive now over-rides all previous programming and runs at the adjustable pre-set speed or PID controlled speed. The inverter tells the hvac motors it controls to begin running in reverse, pulling smoke out as opposed to pumping air in. This smoke extraction greatly aids with visibility, allowing those in the building to see escape routes – something particularly useful in underground structures where there may be no natural light. 
The fireman’s override has proved so successful that it is now being used by architects & consultants in the design of commercial buildings, allowing them to design structures, knowing that a smoke extraction system will form part of the fabric of the building. Escape route management strategies can then be formulated to allow the fastest egress of people possible.
The ABB ACH580. In critical applications, not all drives are created equal. Some are born heroes.