[FUN] FF Cable Conductor Colours

[Stephen Mitschke]

Hi FUN list,We've been keeping all our FF projects using FF cable conductor colors asblack(+) & white(-), to maintain consistency with our traditional instrumentwiring colors. Our instrument techs think black(+) & white(-) whether it's4-20 or FF. We've been trying use the orange jacket to highlight that it isFF wiring. However, I see the Foundation has written a letter to cable suppliersrecommending a new orange(+) blue(-) FF conductor color convention. TheFoundation says they would like to make this convention a recommendedpractice. What are other FF users specifying for wiring conductor colors? Anybodyusing black-white FF conductors, or are we in left field? Jim SpragueAramco [Verhappen, Ian] Don't forget to register for the EUC meeting in Chicago on October 25 atwww.fieldbus.org <http://www.fieldbus.org>

[Stephen Mitschke]

For simplicity I have pasted many of your responses to this one note.Ian We are using the orange(+) blue(-) FF conductor color convention with theorange jacket. Our instrument techs have gone throuth the FF training sothey know that the colors are for FF insturments and not standard 4-20insturments. Danny StreetProject Engineering Pharmacia-------We used black(+) & white(-) in our FF installation here.Rick ShrinerExxon Mobil-------The Orange & Blue came as a surprise to us part way through construction. Weended up with a situation where the panel wiring part of the segment wasblack/white, and the field was Orange/Blue. Personally, I prefer theorange/blue (there are places in the world where red/black is used, and inthere black is (-) in d.c. ciruits)On the same theme, I'd be interested to hear what colour jacket is beingused to identify IS segments - orange / light blue / etc?Andrew Houghton, Aker Kvaerner----------Jim,We (AMEC) last year completed a large FF project in Idaho. We used standardanalog 18 AWG shielded / armoured cable c/w black and white pairs. Ipersonally see no problem with b & w pairs. I do think however, that theorange jacket is a good idea to identify FF runs.Fraser Robb, AMEC------- Some companies use white(+) and black (-). One major petrochemical companyI have worked with used black (+), white (-) in one unit and the oppositecolors in another unit! Bring packaged units or skids into the equationand the issue gets even stickier. The issue is at least one ofconsistency. Because there are many variations to the color coding for plusand minus, I think a new standard for fieldbus would be an excellent to getsome consistency going. Also, the idea of color coding the jacket will easethe burden of maintenance and service people who may be working aroundseveral protocols including 4-20 ma. The ideal would be a standard for eachprotocol, i.e. orange for Foundation, Blue for Profibus, Green for Modbus,black for analog, etc. That's probably asking too much, but what the heck,got to try.Chuck CarterLee College Fieldbus Education Center ----------Jim, We follow the same convention that you just detailed for the same reason.Also we were able to purchase wire that was black and white with orangejacket at a fraction of the cost of the the orange and blue stuff. Ben LarsonInstrument EngineeringTippecanoe LaboratoriesEli Lilly and Company----------Jim,We have seen it both ways. One good arguement for the orange + and blue -conductor color is that the technician knows if a wire pair is a dedicatedpair (black and white) for 4-20, or a bus (orange and blue) which may effectmany devices. This situation has come up where HART / analog and Foundationfieldbus wiring are in the same junction box. This happens frequently whereexisting devices, existing junction boxes, or devices not available infieldbus are in the process with fieldbus devices. I have also noticedother bus type cable, for example ASi bus cable uses orange and blue.Most instrument technicians I talk with tell me they can deal with eithercolor combination, but site wide consistency is very important. If you doit one way, do it that way everywhere in the site.Others may have different opinions. I hope this is valuable.Regards,Tom WallaceEmerson Process Management

[Stephen Mitschke]

I think white should be positive & black negative if keeping withtraditional instrument wiring.Thx KenKen WorkmanTrades Team Leader JCGCP 780-333-7309 e-mail kenw@pengrowth.com fax 333-7337 --------For the Suncor Firebag Project we also used the white(+) and black(-)convention. It makes sense to the field personnel.Wes Meger (Suncor)

[Stephen Mitschke]

As part of our future plant design specifications we are utilizing the sameorange (+), blue (-) conductor insulation colors, but that's a new systemwith no legacy wiring. For existing systems that wanted to save costs andutilize large amounts of existing wiring, I can see where they would adaptthe standard that you have. I don't think you're out in "left field".Contrary to what the Foundation might be recommending to cablemanufacturers, however, we have chosen a different color convention for ourFF cable jackets, and our other future bus cable jackets, making them eachunique and easily identifiable. We are using as a standard:Yellow Jacket Foundation FieldbusBlue Jacket Devicenet Purple Jacket Profibus Black Jacket Modbus Orange Jacket ASI Hope that helps, Jay Kalinowski ------------We use the Belden 3076F cable almost exclusively . . . it's been black &white insulation on conductors with an orange jacket for at least 3 yearsnow. We use black = +. The "interlinkBT" Type 490 yellow-jacketed cable hasblue & brown insulation - I think we use brown for +.John RezabekBP BDO Manufacturing------------Ian, Woodside Energy Australia use white positive and black negative.Jim Russell----------We are using a blue jacketed cable [not yet actually connected :( ] on thebasis that the FF system we will be using is intrinsically safe. apparentlythere is a new requirement that IS cable be blue.Our default standard for the cores (with decron) is to use black fornegative. Black or blue are traditionally always -ve in power situations,and this has been carried through. I don't really understand why you would want to use black for negative, butthis is Australia not America. I am informed that Europe also uses black for negative. Russell Mackenzie Coogee Chemicals Australia -----------Hi Ian,The couple of projects I have seen last year were all using black (+) &white (-) with black jacket. At least on one instance, the selectioncriteria was "use existing infrastructure as far as possible" (and we hadexisting spare cable so it was a no brainer). On the other project I thinkit was a question of site wide consistency.However, I do prefer separate colour code i.e. orange (+) & blue (-) withthe orange jacket because the separate colour "flash" in to tech's eyes whenthey are working on or around the FF circuit. This is obviously veryimportant because a mistake can cause a loss of multiple devices.RegardsKalpen VachharajaniPaton Controls Limited

[Stephen Mitschke]

In addition to the other comments already made on this thread I would liketo contribute the following as well.The issue of polarity is not supposed to be an issue with Fieldbus, but atleast in the older devices it still mattered so it is my suggestion that youdo keep track of polarity in your systems and be consistent across yoursite.Regarding colours, why not use the cable that is most commonly available inyour area and then use one of the following options to differentiate yourFieldbus cables, or if you want each type of cable (Analog, Serial,Discrete, fieldbus)?- Coloured ferrules- Coloured lugs- Coloured Heat Shrink on the end of the wiresEach or all of these three options can be implemented at the same time asyou place the wire tags on your signal cable at each termination, thuskeeping labour to a minimum as well.Ian -----Original Message-----Hi Ian,Further to Jim's question about cable color codes, I just wanted to flagthat Jim is pretty much thinking from a North American perspective. Yes, inNA there is a common practice for using black (+) and white (-) wires forconnection of analog field devices. However, in other parts of the world(like EMEA) there is no such standard practice. I've seen all the colors ofthe rainbow used in field wiring. Attached picture was taken in Europe on asite of a big chemical company.Kind regards,Jean-Marie AllietHoneywellIndustry Solutions - Technology[Verhappen, Ian] Don't forget to register for the EUC meeting in Chicago on October 25 atwww.fieldbus.org <http://www.fieldbus.org>

[Stephen Mitschke]

A little late on the reply but on the Malampaya project (1600+ FFb devices)we are using Bk (+ve), Wht (-ve) for the field wiring between Relcom JBs andfor home run cables. However, the InterlinkBT pre-fab cord sets are Blu(-ve), Brn (+ve). This colour code is continued from the cord set to theRelcom block then the inter block connection cables are as indicated above;Bk (+ve), Wht (-ve).Just less than half of our segments are I.S. and therefore cables aresheathed in blue or are tagged at the ends as I.S. with blue markers.RegardsKen Jones, Shell [Verhappen, Ian] Don't forget to register for the EUC meeting in Chicago on October 25 atwww.fieldbus.org <http://www.fieldbus.org>