Min Separation of Cat6 Cable in EMT to Other Current Carrying Conductors in EMT

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Anode

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Minimum separation of Cat6 in EMT to other current carrying conductors in EMT?

Our wireman has a suspicion likely from his many years of wisdom that such a separation exists.

Can any of you provide a section of code, or some standard, or something that points to what a REQUIREMENT would be, or what a best or common practice is?

We have a monitoring device for a solar pv system that the communications cable runs down into the electrical room. Basically just looking for guidance on best practice.

Thanks in advance!
 
Anode said:
Minimum separation of Cat6 in EMT to other current carrying conductors in EMT?

Our wireman has a suspicion likely from his many years of wisdom that such a separation exists.

Can any of you provide a section of code, or some standard, or something that points to what a REQUIREMENT would be, or what a best or common practice is?

We have a monitoring device for a solar pv system that the communications cable runs down into the electrical room. Basically just looking for guidance on best practice.

Thanks in advance!
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I'm not positive that this is the section of code that applies here, but 830.133(A)(2) seems reasonable: "Network-powered broadband communications cable shall be separated at least 50 mm (2 in.) from conductors of any electric light, power, Class 1, and non–power limited fire alarm circuits."
 
by 830.133(a)(1)(d), you cannot run cat6 in the same raceway as power circuits. Using Innerduct may be compliant; there has been some discussion on that here. the 2" separation is 830.133(a)(2). (2008 NEC referenced)
 
This doesn't sound like network powered broadband to me but no matter. 800.133(A)(1)(2) says the same thing. Basically you can't run LV or communications cables with power conductors in the same conduit. The exception is if those power conductors are enclosed in a listed cable such as type TC, romex, AC, MC etc. and run through the conduit. Conversely, you may be able to get away with running the communications cable in innerduct within the conduit. Either of these methods requires that the cable or innerduct be terminated properly in whatever enclosure the conduit connects to. Separation is required there too but I think somebody here found a CAT cable listed for termination within line voltage control cabinets.

-Hal
 
Requirements aside, it's good wiring practice to separate COMs cables from power conductors. Unshielded twisted pair Ethernet is pretty robust, but not completely immune to induced interference. Separation of cables, even by a few inches, goes a long way towards protecting COMs from interference.

I have no idea what devices you're connecting, but is fiber optic Ethernet an option? Perfectly OK to run in conduit with power conductors and completely immune to induced noise. Media converters on each end of the run will handle the copper to fiber transition. You can run much longer distances with fiber than you can with copper too.

Also know that many devices use CAT5/CAT6 cable to carry COMs other than Ethernet. Many devices use CAT5/CAT6 to carry RS485 COMs, or other proprietary wiring schemes. In that case, Ethernet media converters won't work.

I believe Allan Bradley makes a CAT5 cable that has a jacket rated to 600V for use in MCC cubicles. I'm don't think that gets around the requirement for separating COMs cables and power conductors in the same conduit though.



SceneryDriver
 
Thank you for the quick responses, sorry I could not respond as quickly. Busy week.

Paul1955 said:
I'm not positive that this is the section of code that applies here, but 830.133(A)(2) seems reasonable: "Network-powered broadband communications cable shall be separated at least 50 mm (2 in.) from conductors of any electric light, power, Class 1, and non–power limited fire alarm circuits."
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So is 2" the answer for safety per the referenced code? I am also looking for best practice. To be clear, the coms and power are not being proposed in the same conduit! That was my mistake in the posting.

JFletcher said:
by 830.133(a)(1)(d), you cannot run cat6 in the same raceway as power circuits. Using Innerduct may be compliant; there has been some discussion on that here. the 2" separation is 830.133(a)(2). (2008 NEC referenced)
Click to expand...

Sorry, once again me thinking I was being clear, while trying to be succinct. I am not talking about running coms and power in the same conduit. They are in two separate conduits. I am looking for code or best practice distance separation between conduits. First and foremost, code related (safety), then best practice. Sorry I was unclear. :roll:

hbiss said:
This doesn't sound like network powered broadband to me but no matter. 800.133(A)(1)(2) says the same thing. Basically you can't run LV or communications cables with power conductors in the same conduit. The exception is if those power conductors are enclosed in a listed cable such as type TC, romex, AC, MC etc. and run through the conduit. Conversely, you may be able to get away with running the communications cable in innerduct within the conduit. Either of these methods requires that the cable or innerduct be terminated properly in whatever enclosure the conduit connects to. Separation is required there too but I think somebody here found a CAT cable listed for termination within line voltage control cabinets.
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Was aware of the ability to run listed cable with power, which I know has been done in the past for dc optimized systems, which we no longer do. But again, sorry for the confusion, not in the same conduit. See above.

SceneryDriver said:
Requirements aside, it's good wiring practice to separate COMs cables from power conductors. Unshielded twisted pair Ethernet is pretty robust, but not completely immune to induced interference. Separation of cables, even by a few inches, goes a long way towards protecting COMs from interference.

I have no idea what devices you're connecting, but is fiber optic Ethernet an option? Perfectly OK to run in conduit with power conductors and completely immune to induced noise. Media converters on each end of the run will handle the copper to fiber transition. You can run much longer distances with fiber than you can with copper too.

Also know that many devices use CAT5/CAT6 cable to carry COMs other than Ethernet. Many devices use CAT5/CAT6 to carry RS485 COMs, or other proprietary wiring schemes. In that case, Ethernet media converters won't work.

I believe Allan Bradley makes a CAT5 cable that has a jacket rated to 600V for use in MCC cubicles. I'm don't think that gets around the requirement for separating COMs cables and power conductors in the same conduit though.
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I am with all of you 100%, good practice to separate. Which is what we are doing here. Again looking for code related support to minimum separate of coms conductors to power conductors, when each is in its own conduit. Proximity type question with respect to best practice as well, given the induced currents or noise that can be present. :)

Any more thoughts here will be greatly appreciated. :D
 
BICSI standards (Telecommunications Distribution Method Manuals) would have much more information on best practices of the v/d/v cabling than the NEC. 2" separation and, where conduits/cabling cross, do so at a 90* angle
 
Sorry, once again me thinking I was being clear, while trying to be succinct. I am not talking about running coms and power in the same conduit. They are in two separate conduits. I am looking for code or best practice distance separation between conduits. First and foremost, code related (safety), then best practice. Sorry I was unclear.
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If we had known that in the beginning this thread would only consist of two posts. Answer is there is no spacing requirement- code, practice or otherwise. There would be no reason.

-Hal
 
Anode said:
Sorry, once again me thinking I was being clear, while trying to be succinct. I am not talking about running coms and power in the same conduit. They are in two separate conduits. I am looking for code or best practice distance separation between conduits. First and foremost, code related (safety), then best practice. Sorry I was unclear. :roll:
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I won't beat you up for being unclear. I read your post and knew that you were talking about spacing between conduits, not between Cat6 and line volt in the same conduit. IMHO, for me to believe that you were talking about the latter, I would have had believe you to be either very inexperienced or not particularly bright, which tends to be assumed quite often by a large percentage of members of this forum.

Perhaps I'm not disgruntled enough or my twenty years in the field hasn't been enough time to completely rob me of my belief in humanity, but I don't believe that assuming the worst about posters is the first place we should go, nor do I think that we should act like the sole purpose of responding to a thread is to close it out as soon as possible. If anything somewhat ambiguous subject, just like complicated issues, can lead the discussion to places where it might not normally go with simply a yes, no, number, or article reference would. The purpose of this place, if no other, is for the exchange of information, experiences, opinions, and ideas, so that we may all have the opportunity to consider things we may have never considered before and continue our education in this industry together. Acting like we're paid to respond to posts, and that our time is invaluable and wasted by not getting people out the door as quickly as possible discourages dialogue and pushes away potentially valuable members.
 
Anode said:
I am with all of you 100%, good practice to separate. Which is what we are doing here. Again looking for code related support to minimum separate of coms conductors to power conductors, when each is in its own conduit. Proximity type question with respect to best practice as well, given the induced currents or noise that can be present. :)

Any more thoughts here will be greatly appreciated. :D
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Usually, I'd see no issue with two metallic conduits running next to each other. The metallic conduit provides good high frequency shielding to the COMs cables inside, and since Ethernet is galvanically isolated, induced currents would have to be pretty high to cause any issues.

The only issue I see is if the power-carrying conduit contains LARGE supply conductors (I'm surmising over 400A or so) that are heavily loaded. That could conceivably cause induced currents large enough to overcome the galvanic isolation. It depends on parallel length of run as well; a few feet is fine. A few hundred feet may cause problems. If in doubt, separate as much as practicable but not less than 2", especially where parallel runs are long.

And no worries about being unclear. I too guessed you might be after minimum conduit separation distances, but I mentioned "in the same conduit" just to be sure. Many read this forum without posting; I know I did for quite awhile. My hope is that maybe someone else can learn something new, as I have.



SceneryDriver
 
hbiss said:
This doesn't sound like network powered broadband to me but no matter. 800.133(A)(1)(2) says the same thing. Basically you can't run LV or communications cables with power conductors in the same conduit. The exception is if those power conductors are enclosed in a listed cable such as type TC, romex, AC, MC etc. and run through the conduit. Conversely, you may be able to get away with running the communications cable in innerduct within the conduit. Either of these methods requires that the cable or innerduct be terminated properly in whatever enclosure the conduit connects to. Separation is required there too but I think somebody here found a CAT cable listed for termination within line voltage control cabinets.

-Hal
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This quote here seems to say its OK. That's why I asked for clarification.
 
It's like running romex and CAT6 in the same stud bay in a wall. You can do the same thing with romex and the CAT6 through a piece of conduit. The reason is that unlike individual conductors, romex (or TC, AC, MC, etc.) are listed cables and no spacing is required from them. The same could be said for running the conductors through greenfield, sealtite, etc. then putting that in the conduit.

Looking at this from the CAT6 perspective, you could pull the CAT6 through greenfield, sealtite, etc. and put that in the conduit with the individual conductors.

-Hal
 
See 800.133(A)(1)(d) exception #2.

Any cable wire must have the same insulation rating. Cat 6 is not thhn.
Insulation properties must be equivalent.
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That is called reclassifying a CL2 or CL3 circuit. See art 725. Even if you do reclassify you still can't pull the now THHN into a conduit with THHN power conductors with few exceptions.

-Hal
 
canoeman said:
Any cable wire must have the same insulation rating. Cat 6 is not thhn.
Insulation properties must be equivalent.
Click to expand...
That applies to individual conductors and not to cables. For example it would not apply to NM and CAT 6 in a common raceway.
 
What we do..

What we do..

In our Job scopes we state “Conduits caring communication circuits running parallel to power carrying conduits shall maintain a min of 12” spacing. Conduits caring communication circuits running perpendicular to power carrying conduits shall maintain a min of 2” spacing.” But every now and then we have some people who just tie wrap to the 480vac 1200a pipe line and does sometimes cause issues.

We also require all industrial Ethernet to be 600vac rated. We have had issues with Meters and VFDs.
 
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