I am currently installing "on-off" valves in a chemical plant and will be using ASi bus for control. This is a two wire comunication to intelligent devices and the devices obtain their power from the two wire buss (about 30vdc). The question I have is in regard to the proper sealing of the cables for both Class I Div. 1 and Class I Div. 2 Group C &D locations. Most of the manufacturers of the cables and terminators provide instructions/guidelines for these area class installations. For Div. 2 it is essentially to use factory made cables and then have a locking mechanism on the hazardous area side so that the cable cannot be removed under power without some effort. For Div. 1 it is to use a "special Class I div. 1" cable and fitting assembly. The problem is the cable is flexible and essentially "shipboard" cable. My interpretation of the NEC code is that "shipboard" cable is not an approved wiring method for class I Div. 1. Has anyone had experience with this type of buss network and the use of "shipboard" cable in a Class I div. 1 environment? Is there an exception or code article that allows the use of this cable in Div. 1 areas?
ASi communication bus wiring in classified locations
- Thread starter codeuser1
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- Location
- Bremerton, Washington
- Occupation
- Master Electrician
The shipboard cable would be allowed if its a listed cable and can be used in the location.
I am not familiar with the type of data system you are installing.
I am not familiar with the type of data system you are installing.
The only approved wiring methods (501.10) for Class I Div. 1 are conduit, MI cable, MC-HL, or ITC-HL. I can't find where "shipboard cable" is also rated ITC-HL. I don't understand how the vendor recommends the use of shipboard cable in these area classes -- could there be something in code for systems operating at 30V or less? ASi communication buss operates at about 30V. I'm in communicaton with the manufacturer since this info is in printed literature on the public web; but haven't received an explanation yet.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Tom?s point was well taken and worth reiterating. If the whole cable assembly (cable + connectors) is listed for Class I, Division 1, then the specific cable used is irrelevant. This is especially true if it is part of a total manufactured system identified for the use.
The rules for manufactured products listed as complete assemblies are different from those for field fabricated assemblies.
I am not familiar with the referenced system either but, with proper documentation (including instructions), I probably wouldn?t worry about it.
The rules for manufactured products listed as complete assemblies are different from those for field fabricated assemblies.
I am not familiar with the referenced system either but, with proper documentation (including instructions), I probably wouldn?t worry about it.
So far the vendor has given data to support the use of this cable as a "recommended method of installation". I have not yet recieved data that the whole assy. is FM or other agency approved. The rep has supplied data from an API standard for marine and offshore facilities. The standard clearly notes the differences between NEC and itself and the use of this type of cable is for applications that require portability, movement, etc. I can see how this type cable could be successully implemented in a Class I Div. 1 environment since it closely matches ITC-HL (just no corrugated outer jacket - the cable is protected by an inner wire mesh); but, it is not, in my opinion, recognized by NEC code. I guess since this is an industrial establishment that the company's AHJ, most likely the insurance carrier, could approve the use of this cable.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
It has been a while since I dealt with API RP14F.
I note the cable construction under discussion (shipboard cable, marine) is still required to be listed per UL 1309. You are correct; it is not currently a recognized NEC wiring for Class I locations. It probably should be. At least 3 members of the API 14F Working Group (WG) are current or former members of NEC CMP 14. And at least a dozen of them are or were on the RP 500/505 WG (my previous WG). It was through the RP500/505 WG that I originally proposed what would become MC-HL. If I were still active, I would probably suggest an API Proposal for the 2011 NEC cycle to also recognize marine shipboard cable in certain applications. I still have contacts there so I may anyway.
FedOSHA does not regulate ?Fixed and Floating Offshore Petroleum Facilities? - the Coast Guard does. However, if the application you have in mind is under a State or Federal OSHA, you still may want to contact them as well as the insurance carrier. The Coast Guard is represented on the API RP14F WG. Their approval of the wiring method will generally be recognized as a valid to other AHJs.
(Just a note: industrial facilities are not generally exempt from other local AHJs either)
I note the cable construction under discussion (shipboard cable, marine) is still required to be listed per UL 1309. You are correct; it is not currently a recognized NEC wiring for Class I locations. It probably should be. At least 3 members of the API 14F Working Group (WG) are current or former members of NEC CMP 14. And at least a dozen of them are or were on the RP 500/505 WG (my previous WG). It was through the RP500/505 WG that I originally proposed what would become MC-HL. If I were still active, I would probably suggest an API Proposal for the 2011 NEC cycle to also recognize marine shipboard cable in certain applications. I still have contacts there so I may anyway.
FedOSHA does not regulate ?Fixed and Floating Offshore Petroleum Facilities? - the Coast Guard does. However, if the application you have in mind is under a State or Federal OSHA, you still may want to contact them as well as the insurance carrier. The Coast Guard is represented on the API RP14F WG. Their approval of the wiring method will generally be recognized as a valid to other AHJs.
(Just a note: industrial facilities are not generally exempt from other local AHJs either)
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