Explosion protection rating and protection class
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For the instrument, the intrinsically safe type E*aIICT4 is used; can the protection level only be indicated as Ga and not as Gb?
E*a intrinsically safe: E*a stands for Intrinsic Safety; devices of type E*a are suitable for higher safety requirements, such as use in Zone 0 environments. The E*a device does not cause ignition under normal operation or in the event of a single fault, therefore its explosion protection rating can only be marked as “Ga”. In comparison, the E*b type is suitable for Zone 1 environments with lower safety requirements, and therefore can be labeled as “Gb”. Protection levels Ga and Gb: Ga indicates that the device is suitable for Zones 0, 1, and 2, meeting higher safety requirements. Gb: Indicates that the device is suitable for Zones 1 and 2, where the environmental safety requirements are relatively low.
I’m in Zone 2 for explosion protection, but the owner wants to use intrinsically safe instruments. I’m using EX ia IIB T4 Ga; the owner suggests changing Ga to Gb, that is, EX ia IIB T4 Gb. Is this notation correct?
This post was last edited by qqgd on 2024-11-7 09:06. It’s not entirely correct; for cases where Zone 0 is used, Gb won’t work； But if it can be confirmed that they are all in Zone 1 or Zone 2, then there should be no problem. Are there technical agreements or corresponding documents signed by both the supplier and the buyer? In terms of safety and explosion prevention, having the user or buyer sign the documents related to explosion prevention and safety indicates that they acknowledge this, and it also means that the instrumentation and equipment provided by you meet the on-site requirements for explosion prevention and safety.