Customizing electrical devices to work in ex-zones

Problems when using distribution boards to power heating circuits in EX zones

A common problem when using electrical equipment in EX zones is adapting it to the conditions imposed by the explosive atmosphere. It may be caused by the presence of dust, gases, flammable liquids, or vapors of flammable substances, which, when combined with an oxidizer (usually air) and a spark, can lead to ignition.

Due to the fact that standard versions of electrical machines and devices do not have certificates confirming the appropriate tests, let alone the required ATEX certificate, it is necessary to properly protect them.

Popular solutions for switchboards for powering heating circuits in hazardous areas

A popular way to deal with this issue is to move as many devices as possible, including switchboards for powering heating circuits, outside the hazardous area to completely eliminate the problem, or to move them from more hazardous areas (1 and 21) to less hazardous areas (2 and 22), which somewhat reduces the problem.

In practice, in the case of large machines, this is rarely possible, as it would require a complete reconstruction of the existing installation. and adapting the new location. Not to mention the difficulties with parts or sections of technological lines that are structurally impossible to move.

Dacpol – together with its technology partners – offers the possibility of adapting electrical devices to operate in EX zones by installing them in flameproof panels, i.e., those with the EX-d classification. This solution complies with the regulations specified in harmonized standards, and the entire design receives an ATEX certificate, which officially allows the device/set of devices to be used in potentially explosive atmospheres.

Analysis and implementation of a solution for switchboards for powering heating circuits in EX zones

The entire operation involves determining the heat loss of the devices to be installed. Based on this, the enclosure size is selected, which is also influenced by the arrangement of individual components inside (maintaining appropriate spacing between heating elements). It is possible to have the entire system assembled by the supplier, or to have the mounting plate shipped in advance and installed by the user.

For large-scale systems or, for example, electrical switchboards, there is an alternative in the form of a so-called ventilated protection system, or EX-p. This is a modern, easy-to-install, and convenient solution, but it comes at a higher price. The equipment at risk is placed inside a sealed metal cabinet, and a permanently connected compressor pumps in an inert gas (usually air) and maintains a negative pressure. An internal electronic system monitors the pressure level, adjusting it as needed, and, if necessary, disconnects the system.