Most of the deaths or injuries that occur in a fire result from smoke inhalation and intoxication from poisonous gasses. Airflow control is important for smoke management and keeping injuries and deaths as well as building damage to a minimum. The ABB ACH580 override mode VSDs is an important tool for minimising the loss of life and property.

A single digital input activated initiates the ACH580 override mode. This starts a set of programmed parameters controls the operation of the drive system and disables most other control inputs. It is then impossible to edit any of the drive’s parameters during override mode. Moreover, it also ignores specific alarms and faults or reset.

In residential and commercial buildings, it is critical to integrate HVAC components including VFDs into a building smoke control system. Modern smoke control systems can identify the location of a building the fire. Integrating a building’s HVAC components and VSDs into the smoke control system provides helps control it. It stops the fresh air supply to the fire, exhausts smoke, prevents it from spreading and changes evacuation routes.

In large building fires, HVAC fans need two functions: to extract smoke and to control and manage fresh air flows. They must stop more oxygen being fed to the fire, while also delivering air to escape routes and safety zones.

A building’s smoke control strategy depends on many factors such as the number of floors and the construction of the building. A smoke control zone can include several floors and an individual floor may include several smoke-control zones. When a fire occurs in a smoke control zone, all the adjacent zones get pressurised.

ACH580 override mode

Fan pressure limits smoke movement from a smoke control zone to adjacent and unaffected zones. The ACH580 override mode allows it to run some exhaust fans in reverse to provide extra pressurisation. Reverse mode can also help to remove smoke from the building.

The ACH580 override mode can ensure that in complex smoke and airflow situations the fans are running in the way required by fire control. So, it can be an effective tool in any smoke control strategy to extract the smoke, while providing fresh air for people.

Stairwell smoke control

Smoke management for stairwells increases pressurisation to prevent smoke from spreading to other floors. It is to provide both safe evacuation routs for building occupants and staging area for a firefighting crew. A stairwell becomes a high-pressure zone to prevent smoke infiltration to the stairwell.

The use of stairwell pressurisation to ensure escape routes are accessible is easier. Furthermore, if there is a sudden pressure change caused by doors opening or windows blowing out or walls burning away, the VSDs PID controller can alter the motor speed to maintain the correct pressure.

The main used of ACH580 override mode is for fire control and smoke extraction and other application that requires such a function. Such applications include tunnels, shopping malls, arenas exhibition centres and large volume spaces.