What are the explosion-proof requirements for ammonia refrigeration equipment?
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In accordance with the requirements of relevant standards and specifications, the motors and control cabinets in ammonia refrigeration systems should be explosion-proof. Why do equipment manufacturers use non-explosion-proof products, and what is the basis for this?
In the past, insufficient attention was paid to the hazards of chlorine; as a result, equipment manufacturers used non-explosion-proof products, although cost considerations also played a role in this decision. But as attention to safety increases, the requirements naturally rise as well. That said, years of actual operation have also shown that although the motors and control boxes in ammonia refrigeration systems are not explosion-proof, accidents caused by this factor are not common.
The motors and control cabinets in ammonia refrigeration systems are explosion-proof; which standard do they comply with?
According to Article 4.4.4 of \"Electrical equipment for explosive gas atmospheres – Part 14: Classification of hazardous areas\": Experience shows that ammonia is difficult to ignite, and gas releases in the outdoors will disperse rapidly; therefore, the expansion of explosive gas atmospheres can be ignored.
Does that mean it’s not necessary to use an explosion-proof version? The company purchased a piece of equipment intended for adding ammonia, but its electrical wiring is not explosion-proof. Does that mean it can be used right away, as you said? But my device isn’t outside yet; is it inside?
Requirements for going upstairs are specified in the cold storage design standards.
Welcome to the discussion; clear conclusions must be drawn, along with supporting evidence!
According to the Building Code, it is classified as Category B in terms of fire hazard; ammonia poses a explosion risk. In accordance with the Code for Design of Electrical Installations in Explosive Environments, electrical equipment must be of explosion-proof type, and this is what is done in all engineering designs.
I would like to ask Engineer Wu: Which specific provision in the \"Cold Storage Design Code\" allows equipment to be non-explosion-proof?
Isn’t the above mentioned in the new regulations?
This post was last edited by ckwcba on 2015-10-13 at 21:56. In the refrigeration plant design specifications, it is permissible for the start-up control cabinet and motors of ammonia-based refrigeration systems not to be explosion-proof, on the condition that there is a linkage between the ammonia leakage concentration alarm and the emergency exhaust fans; moreover, the volume of air exhausted in emergency situations must be calculated such that the ammonia concentration remains well below the lower limit for explosion to occur. Except that the accident exhaust fans must be explosion-proof, ordinary electrical appliances can be used for others. For details, please refer to clauses 7.2.6, 7.2.11, and 9.0.2 of the Cold Storage Design Code along with their explanatory notes.