Extinguishing systems are utilized in a wide array of applications and are configured based on the environment in which they will be used, the system components, and the extinguishing agent employed. Regardless of configuration, the purpose of an extinguishing system is to protect property and personnel. A critical component that helps achieve this is the suppressant releasing device that initiates the mechanical discharge of the extinguishing agent that will combat the fire.
One of the primary releasing devices used on extinguishing systems is a latching solenoid actuator, also referred to as an electric actuator. Typically an electric actuator is attached to the suppressant’s discharge valve and electrically connected to the Fire Alarm Control Panel (FACP). Upon receiving the suppressant release signal, the electric actuator causes the discharge valve(s) to open and dispense the extinguishing agent from the suppressant storage container.
Supervision on extinguishing systems is implemented to monitor various system features and operability of critical devices. Supervision ensures that an electrical connection is present between the remotely located suppressant initiating device (the electric actuator) and the FACP. Additionally, this supervision ensures proper mechanical installation of the suppression system release device. A change in status of the supervisory circuit’s state will signal the extinguishing systems control panel, indicating inoperability of remotely located devices.
Reasons for Action
The position of the releasing device on the discharge valve is a critical system requirement due to the connection controlling the mechanical release of the agent. When the actuator and its position are left unsupervised, opportunities for suppression system failure are introduced. Human installation error is the easiest potential failure mode to identify and already has recorded incidents. The electric actuators are installed on the release valve manually and routinely removed from the extinguishing container for system maintenance and functional testing of the actuator. Without a supervisory signal requirement, a removed electrical connection between the system control panel and actuator does not result in any system alarm conditions. This leaves the responsibility of proper re-installment solely on the technician that removed the actuator with no overall system or secondary operability checks.
Multiple cases have been reported of electric actuators improperly installed by a technician and in some instances left physically unattached altogether. This leaves the system unable to function, creating a dangerous situation if the fire suppressant system is still viewed as operational. The probability of this scenario occurring increases based on the number of people that maintain and inspect the system throughout its useful life.
Most suppressant agent releasing devices are removable components, which raises security concerns with tampering or inadvertent changes in position. Due to an often obstructed view between the mating surfaces of the components, any damage or nonconforming parts impeding proper fit or function could go undetected. Releasing devices also have lengthy intervals between periodic maintenance and inspections allowing for an issue to go unnoticed. If the extinguishing system control panel cannot detect the position of, or changes to the electric actuator, the same suppression system failure as an improper installation occurs. Preventable human errors and problems with solvable engineered solutions are no longer an accepted failure in the technological world of today.