Introduction. To localize fires in electrical cabinets, autonomous thermoactivated gas fire extinguishing devices (ATGFED) have recently become more and more widespread. These devices are produced, subject to mandatory confirmation of conformity in the form of certification, but there are no regulatory requirements and test methods for them. Their certification is carried out according to technical solutions developed on the basis of current standards and containing test methods, which are developed for other products, but applicable to the devices under consideration.

The purpose of this paper is to develop a methodology for determining the extinguishing ability of autonomous thermally activated gas fire extinguishing devices. For this purpose, it is necessary to:

Materials and methods. To determine the fire extinguishing ability was used ATGFED in the form of hermetically sealed at both ends of the polymer tube filled with gas extinguishing agent in the liquid phase. For testing were taken devices with protected volume from 50 to 2,000 dm3. The experiment was conducted in a fire chamber with variable internal volume made of non-combustible material in the form of a cabinet with two doors.

Results and their discussion. The developed methodology makes it possible to determine the fire extinguishing capacity for each unit of the device separately under conditions as close as possible to the operating conditions. A series of tests showed that the fire extinguishing capacity of the considered ATGFED with a protected volume from 50 to 2,000 dm3 is in the range from 48 to 125 seconds.

Conclusions. The design of a fire chamber with a variable volume, allowing to correctly carry out the determination of the fire extinguishing ability of devices with a protected volume from 200 to 2,000 dm3 is proposed. To ensure stable operation, a hearth-initiator is applied, which provides thermal activation of autonomous devices. The fire extinguishing ability of ATGFED is determined.