1. Spacing Between Components and Enclosure Walls
It’s crucial to maintain a specific gap between components and the walls of their enclosure. This space should exceed twice the required electrical clearance, influenced by the equipment’s voltage and power, facilitating easier installation. As a rule, this distance should not fall below 15 millimeters, especially in medium and small-sized devices.
2. Internal Placement of Components
Positioning components internally is advisable to avoid the risk of sparks or electric arcs from switches damaging the enclosure walls. Previous international reports have documented cases where electric arcs in explosion-proof equipment pierced the explosion-proof enclosure walls.
Moreover, in explosion-proof devices, it is imperative that switch contacts are not located on the plane of the explosion-proof joint surface. This placement minimizes the chances of explosion byproducts escaping through gaps in the joint surface upon ignition.
3. Internal Positioning of Heat-Generating Components
Components that generate heat should be installed along the edges for optimal heat dispersion, thus reducing internal temperatures. If necessary, the bases of these heating components should be affixed to the walls of the enclosure, with thermal paste applied between them for enhanced heat dissipation.
4. Direction of Switch Components Installation
For wall-mounted electrical devices, it’s essential to install contact-type switches in a manner that ensures the handle powers the device when switched up and disconnects it when switched down. The reverse arrangement could lead to severe outcomes, like accidental power connection due to non-human factors such as vibrations. Such risks are unacceptable.
5. Isolation of Components
While configuring components, one must consider not only the creepage distance for electrical clearance but also the need for isolating certain components or terminals with partitions to prevent interference. However, in explosion-proof electrical devices, it’s crucial to avoid setting up internal partitions that could lead to the risk of compounded pressure explosions.