Gas Types for Positive-Pressure Electrical Equipment
The protective gases used in positive-pressure electrical equipment should be non-flammable and incapable of ignition on their own. Additionally, these gases should not compromise the integrity of the positive-pressure enclosure, its conduits, and connections, nor should they affect the normal functioning of the electrical equipment.
Therefore, clean air and some inert gases, like nitrogen, are suitable for providing protection.
However, it’s important to note that when using inert gases as protective agents, there should be awareness about the potential asphyxiation hazards they pose.
Temperature of the Gas
The temperature of the protective gas at the inlet of the positive-pressure enclosure should typically not exceed 40°C. This is a crucial consideration.
In certain special scenarios, the temperature of the protective gas may rise or fall significantly. In such cases, the maximum or minimum permissible temperature should be clearly marked on the casing of the positive-pressure electrical equipment. Sometimes, it’s also necessary to consider how to prevent the impairment of electrical components due to excessively high temperatures, how to avoid freezing at low temperatures, and how to prevent the “breathing” effect caused by alternating high and low temperatures.
