Intrinsically safe

[Jameshoward]

I'm at a water treatment plant
the electrical engineer is directing us to use sch80 PVC. In a class 1 division 1 space. Connecting a intrinsically safe limit switch,for tank flight mechanicals . Referencing ate 504.20
im looking at 501.10 -A 1
is PVC acceptable ,if not should state inspector be made aware,not to mention added cost ( not for nothing contract drawings define area to be wet and corrosive )

 

[Smart $]

504.20 applies to IS circuit wiring, i.e. any Chapter 3 method is permitted.

 

[rbalex]

I rarely add comments where someone else has given a correct answer. However, I would caution anyone using intrinsic safety (IS) [Art 504] to give attention to the full Article, especially Sections 504.50 to 504.70. PVC may have some grounding/bonding issues not usually anticipated by "Any wiring method suitable for unclassified locations..."

Also read the rest of Sec 504.20 for other cross-references. I would also consider the Informational Note (IN) to Section 504.1. In other words, Article 504 doesn't tell you all you need to know about IS. Whether or not ANSI/ISA 12.06.01 is locally adopted it is an OSHA enforceable standard.