# DMX vs Cat6



## ACTSTech (Nov 18, 2019)

We have basically been evicted from our venue and are looking for a new home. There’s already a few possibilities but none are ready, everything will have to be installed. I pulled our dimmer racks today and we’ll be reusing as much as we can since this was an unforeseen occurrence that’s going to be expensive, but I ran into some issues and hope some people might share thoughts.

Our light board will need to go eventually. Currently, the board sits in the rear of the old venue and the 5-pin DMX cable runs to the dimmer rack. We’ll probably do the same to start, but if we upgrade the board, should I run DMX from the new booth to the rack, to a splitter, or run Cat6 as well? I’m not up to speed on the new lighting systems, but I’m reading as many posts as I can. I originally thought just 2 DMX lines, one to the racks then one for a second universe (I think I’m using that right) in case we get movers for FOH. Eventually the dimmer racks will be retired I’d assume, so would it be worthwhile running Cat6 at the same time? I’m already planning on buying a spool for runs from the sound booth to the rack, so I’ll have it. We don’t have any lighting equipment that uses it at the moment, but if I’m running one cable I might as well run 8.

And I know wireless DMX seems to be popular, but I’m terribly old school and fearful of wireless technology. I’ll be reading, but any help is welcome!


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## Rob (Nov 18, 2019)

THIS is a handy reference.


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## RC4Wireless (Nov 18, 2019)

Talk to me about wireless DMX. I’ve been doing this for 30 years. There’s nothing to be afraid of, you just need the right system for your needs and venue. Lifetime Warranty, too!

Jim
[email protected]


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## DrewE (Nov 18, 2019)

If you pull cat 6 cable, you can use it for a few universes of normal DMX512 and then swap it over to some Ethernet-based alternative when the need for that comes up. In other words, Cat 6 cabling will be fine for standard DMX512 signaling; there's no particular reason I can see to pull anything else for a new installation. It would, in my opinion, be worth pulling a few Cat6 cables while you're at it, or at the very least leave a pull string in place to be able to pull more in the future, should the need arise--say for digital audio distribution. I guess it partly depends on how much pain it is to do the cable pull; I try to always leave a string in place if it's at all tricky in any way, since mason line or similar is really cheap compared to one's time and skinned knuckles and mental health.


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## DavidJones (Nov 18, 2019)

Just use Cat6. Look up TMB sneak snake. A bunch of companies make the same things. These are completely passive, just using the twisted pairs for DMX signal. You can get 1, 2 ,3 universe versions over one Cat5/6, and 4 universes with Shielded cable. Sounds like a single Cat to 5-pin barrel at each end will be all you need for now. You can even just make some of these adapters yourself for a single universe. For multi-universe breakouts, I'd recommend the professionally built ones, because they are much nicer and it would be a hassle to get all the parts and make them yourself.


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## ACTSTech (Nov 19, 2019)

DrewE said:


> If you pull cat 6 cable, you can use it for a few universes of normal DMX512 and then swap it over to some Ethernet-based alternative when the need for that comes up. In other words, Cat 6 cabling will be fine for standard DMX512 signaling; there's no particular reason I can see to pull anything else for a new installation. It would, in my opinion, be worth pulling a few Cat6 cables while you're at it, or at the very least leave a pull string in place to be able to pull more in the future, should the need arise--say for digital audio distribution. I guess it partly depends on how much pain it is to do the cable pull; I try to always leave a string in place if it's at all tricky in any way, since mason line or similar is really cheap compared to one's time and skinned knuckles and mental health.



We’re an extremely small group, so I’m having a hard time imagining how many universes we’d ever use. Of course I live in the dark ages, but I’m trying!

My first instinct is to run two lines of cable from the booth to wherever the dimmer racks are located, one for use, one for redundancy. In the old venue, I was thinking of running two lines from the racks back to a front of house location to a distribution box, but from what I’m reading I could skip that and run a line (or 2 because I’m neurotic) straight to the FOH to a distribution box and call that a new universe. 

Since I’ll be using shielded cable, I’m assuming that it will protect against interference. I’ll still use conduit, separate it from my audio runs, and pull strings go in the same time as cable regardless. Jim, what are the big sources of interference for wireless DMX you’ve seen? We’re not large, but our old home had unique problems, like the plaster and lathe walls were wire reinforced, so it was like an enormous faraday cage. No cell service, but any bad wire, circuit, fluorescent light, curling iron, refrigerator, etc wreaked havoc on wireless mics regardless of the frequency. Plus we were close enough to the one radio station that if we opened to fire door and they were broadcast a high school football or basketball game, we could pick it up on old toasters. Like I said, I’m not against learning because this is all new to me.

We’re moving fast and furious trying to save next year’s season, so instead of a little pressure I’m on defcon 6.

Thanks for the input everyone. I search but I’m not sure what I’m searching for most of the time.


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## RickR (Nov 19, 2019)

Cat5e or 6 cable is cheap and does a lot. Pull some everywhere, left right, high, low, front, racks, booths, etc! I suggest pulling in a star pattern with everything joining in one place, and creating a DMX patch bay until you go network. You will want networking someday. Wireless can be great but wire is usually far cheaper and more reliable. 

No need to use shielding in conduit.


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## macsound (Nov 19, 2019)

Something to be aware of that I wasn't. Some shielded Cat6A has larger wires inside and a larger exterior jacket. This means - even for the well versed - crimping RJ45s is a nightmare and will require larger boots and larger gauge RJ45s.
Although I'd definitely recommend pulling the wire now, because now is always better than later, pull a few Cat5e and a couple more Cat6A for the future. 

I'm trying to scare you because I was gutsy once and screwed myself. I've made 1000s of Cat5 cables and stripping and crimping usually takes me 1 minute. Putting one connector on a 23AWG Shielded CAT6A took me about 15 minutes of complete grief.


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## Eleanor Saitta (Nov 20, 2019)

If you actually need CAT6 performance, it really doesn't make a ton of sense to crimp yourself any more. I used to make all my own cables back in the day, but they've gotten so much cheaper and the quality standards have gone up so much that I wouldn't dream of it any more now. In particular, if you think you're ever going to run anything other than DMX over them (and chances are pretty good that you will), I'd strongly recommend just running machine-crimped CAT6 or CAT7 — you don't want to find out in ten years that you're going to have to go digging in the walls because you can't get a GigE link to work.


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## RonHebbard (Nov 20, 2019)

Eleanor Saitta said:


> If you actually need CAT6 performance, it really doesn't make a ton of sense to crimp yourself any more. I used to make all my own cables back in the day, but they've gotten so much cheaper and the quality standards have gone up so much that I wouldn't dream of it any more now. In particular, if you think you're ever going to run anything other than DMX over them (and chances are pretty good that you will), I'd strongly recommend just running machine-crimped CAT6 or CAT7 — you don't want to find out in ten years that you're going to have to go digging in the walls because you can't get a GigE link to work.


 *@Eleanor Saitta* If you intended to pull multiple runs through existing empty conduit, and didn't have space to pull pre-crimped ends through, even if staggered, would you buy cables with only one end pre-crimped and crimp the blank ends post installation OR would you buy pre-terminated cables and cut one end off for pulling, then crimp your blank ends? 
In my mind, this would come down to purchase costs, perhaps buying pre-manufactured cables and cutting one end off is the more economical route to go due to mass production rather requesting a "special" cable*?* 
Toodleoo! 
Ron Hebbard


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## ACTSTech (Nov 20, 2019)

macsound said:


> Something to be aware of that I wasn't. Some shielded Cat6A has larger wires inside and a larger exterior jacket. This means - even for the well versed - crimping RJ45s is a nightmare and will require larger boots and larger gauge RJ45s.
> Although I'd definitely recommend pulling the wire now, because now is always better than later, pull a few Cat5e and a couple more Cat6A for the future.
> 
> I'm trying to scare you because I was gutsy once and screwed myself. I've made 1000s of Cat5 cables and stripping and crimping usually takes me 1 minute. Putting one connector on a 23AWG Shielded CAT6A took me about 15 minutes of complete grief.


Oh, I’m well aware of the differences, but it’s good to note. There’s subtle differences in brands too, some jackets are thicker, some insulation is a hard plastic, almost rigid. And even with the right crimped,

RonHebbard said:


> *@Eleanor Saitta* If you intended to pull multiple runs through existing empty conduit, and didn't have space to pull pre-crimped ends through, even if staggered, would you buy cables with only one end pre-crimped and crimp the blank ends post installation OR would you buy pre-terminated cables and cut one end off for pulling, then crimp your blank ends?
> In my mind, this would come down to purchase costs, perhaps buying pre-manufactured cables and cutting one end off is the more economical route to go due to mass production rather requesting a "special" cable*?*
> Toodleoo!
> Ron Hebbard


Since I’ll be pulling all new wire through all new conduit, I’d prefer running my own wire and cutting it myself. Especially as whatever venue we move to will be all new installation. However, I know the benefit of pre-made cable. To me, it really comes down to where it’s going, pitfalls, and sweat labor. The venue I just removed things from was mostly simple, because I cut off ends. The conduit was full, and even with pull line, it would have been difficult to get any wire through, let alone terminated wire.

If, going into this, I can anticipate so many wires going where, plus leave room for future expansion, I’ll pick a large enough conduit. In that case, I’d consider per-terminated. If I didn’t have a choice and had to pull in old conduit, especially if it’s got some bends, unterminated.

I’ve seen enough mic cable stuck when an overzealous “techie” thinks they can just pull a 100’ cord through conduit.


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## DavidJones (Nov 20, 2019)

I'm not sure I've ever heard of anyone pulling pre-terminated cable in a conduit. Even if you did, where do you order a specific length of install grade cable pre-terminated? Plus it's a PITA to pull cable that is not coming right out of the box. Yes, Cat6 RJ45 connectors are different than the ones for Cat5e, so it is important to get the right connectors and crimpers. If you have not terminated these before, there is always YouTube. Also, ask around, there is a good chance you know somebody that can help.


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## tdrga (Nov 20, 2019)

Also worth mentioning that best practice is to terminate permanently run Cat5/6/+ cables with a female jack and use a patch cord to make the connection to equipment. Solid conductor CAT cable is not going to hold up to repeated flexing like a stranded patch cable will.
-Todd


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## eadler (Nov 20, 2019)

All this talk about crimping... for installed cabling you should be pulling solid wire cable punching down into jacks. Buy some keystone wall plates or surface mount plates and punch them down. A lot easier and a lot more stable than crimping a connector. Then you can buy preterminated stranded wire cables to interconnect equipment.


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## RonHebbard (Nov 20, 2019)

DavidJones said:


> I'm not sure I've ever heard of anyone pulling pre-terminated cable in a conduit. Even if you did, where do you order a specific length of install grade cable pre-terminated? Plus it's a PITA to pull cable that is not coming right out of the box. Yes, Cat6 RJ45 connectors are different than the ones for Cat5e, so it is important to get the right connectors and crimpers. If you have not terminated these before, there is always YouTube. Also, ask around, there is a good chance you know somebody that can help.


 @DavidJones Every now and again, the company I free-lanced with would purchase pre-terminated RJ cables, I'd stagger the ends by approximately 1" per cable, tape them along side a metal or fiberglass fish and haul them through conduit, typically metal, 1 or 1.25" ID EMT. (Electrical Metallic Tubing) as we refer to it here in Canada. I recall it commonly being referred to differently within Donnie's walls. 
Toodleoo! 
Ron Hebbard


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## eadler (Nov 20, 2019)

@RonHebbard People call it 'conduit' when they aren't being specific. That metal stuff you describe, designed for wires and cables? yea, we call that EMT too. We've also got Schedule 40 PVC and Schedule 80 PVC in common use for conduit.


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## RonHebbard (Nov 20, 2019)

eadler said:


> @RonHebbard People call it 'conduit' when they aren't being specific. That metal stuff you describe, designed for wires and cables? yea, we call that EMT too. We've also got Schedule 40 PVC and Schedule 80 PVC in common use for conduit.


 *@eadler* You also have '"Seal-Tite / Liqui - Tite Nylon coated, tightly woven, Flex. 

On the strip in the heart of downtown 'Vegas, I was totally ASTOUNDED by the number and sizes of pre-manufactured Flex-El's my IBEW brethren installed in labor saving preference to bending anything larger then 3/4" I.D. 

I was also startled by the number of cordless, hand-held, saws equipped with _TRULY VICIOUS_ looking Piranha blades in common everyday use to cut EMT where I'd still be using my trusty, fine-tooth, Armstrong powered hacksaw. 
Toodleoo! 
Ron Hebbard


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## macsound (Nov 20, 2019)

I too am amazed Ron at how some electricians would rather bend 10 1/2" EMT than buy one prebent 4". Some have told me it can be done but they'd rather use the 1/2"


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## RonHebbard (Nov 20, 2019)

macsound said:


> I too am amazed Ron at how some electricians would rather bend 10 1/2" EMT than buy one prebent 4". Some have told me it can be done but they'd rather use the 1/2"


 *@macsound* I began my IBEW Installation and Maintenance apprenticeship in June 1967 and spent my entire first year to the day installing literally miles of 2.5" and 4" ID fibre duct underground joining 11 new poured concrete manholes together. 
During my 1st year I also bent 4" Blue 'Genel' - Coat schedule 40 steel rigid with a Blackhawk segment bender. 
In my second or third year, I progressed to bending 4" rigid 90's and offsets with a hydraulic Greenlee 'One-shot'. Once I'd met and mastered the one-shots, I rarely went back to Blackhawks and / or manually operated Chicago benders again. 

Oh how those Greenlee 4" one-shots spoiled me.
Some years post my apprenticeship, electrically powered 'Clock style' benders appeared; I've never used a 'Clock' bender but definitely bent my share of 1.25" EMT by hand (and foot) with EMT hand-held / arm-strong powered manual benders with the two position foot rest. 
Thanks (and no thanks) for the memories. 
Toodleoo! 
Ron Hebbard


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## Eleanor Saitta (Nov 20, 2019)

From my perspective, every high-bandwidth connector you don't have to terminate yourself is one you can't screw up. But yes, if you're pulling long enough runs, or enough of them, connectors are going to be a pain. It may be worth borrowing one of the Fluke network bandwidth testers for a day once everything is done to make sure you're getting the full expected performance of the cables. The day you suddenly find yourself needing to run 4k video over an HDbaseT transceiver you'll be very happy you did.


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## RonHebbard (Nov 20, 2019)

Eleanor Saitta said:


> From my perspective, every high-bandwidth connector you don't have to terminate yourself is one you can't screw up. But yes, if you're pulling long enough runs, or enough of them, connectors are going to be a pain. It may be worth borrowing one of the Fluke network bandwidth testers for a day once everything is done to make sure you're getting the full expected performance of the cables. The day you suddenly find yourself needing to run 4k video over an HDbaseT transceiver you'll be very happy you did.


 *@Eleanor Saitta * Borrow? The company I was free-lancing for owned one of the Flukes; fully testing each and every cable was a standard part of every installation, along with including 10% spares. 
Toodleoo! 
Ron Hebbard


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## Eleanor Saitta (Nov 20, 2019)

RonHebbard said:


> *@Eleanor Saitta * Borrow? The company I was free-lancing for owned one of the Flukes; fully testing each and every cable was a standard part of every installation, along with including 10% spares.



Eh, I'm just saying that if you're in-house at a single venue and worried about whether it's worth pulling CAT5, you might not want drop $1500 on a cable bandwidth tester for a use case you don't currently have for those cables.


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## RickR (Nov 21, 2019)

There is a point in all tech where DIY is a distant 2nd to hiring Pros!


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## ACTSTech (Nov 21, 2019)

RickR said:


> There is a point in all tech where DIY is a distant 2nd to hiring Pros!


You also have to look at cost. I’d love to bring in some pros, but when it comes to bringing in one pro or having enough money to have programs and tickets printed, you bite the bullet and pull the wire yourself. Or you get on ControlBooth and ask for help from people who understand that sometimes you do these shows because you enjoy it even when you don’t get paid.


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## mbrown3039 (Nov 27, 2019)

Run as many cables as the conduit (or raceway/J-hooks if "temporary" or plenum-rated) will hold; Cat5e is good for most things today, but shielded Cat6 is a must for high-quality video. Check around with local electricians and data installers -- you'd be surprised how many partially-used spools of cable they throw away (generally, anything under 250-300' is tossed). As for crimping, the Belden connectors for shielded Cat6 are universally accepted but a major PITA to install. I have been using the Platinum EX series connectors (and tool, which has interchangeable dies for Cat5 v. Cat6) for a couple of years now with just one failed crimp (and now I always wear my glasses when terminating, lol).

Not sure exactly where you're located, but there may be a couple of CB members willing to lend you a hand. m


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## DIYLED (Nov 28, 2019)

I usually use cat5e with molded RJ45's. Bestlinknetware has a variety of lengths. In some situations it can be pulled with l-com brand covers taped over the connectors, and hardware stores have electrician's lubricant. But it is easier to pull non-crimped cat5e over long distances, tight openings, and turns. Another trick is cut one end off a pre-made cable. That reduces number of DIY crimps by 50%. Code requires data be separate from power in conduits. If it's not, it must be shielded to work, and shield connected to DMX ground at at least 1 end of each cable.


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## RonHebbard (Nov 28, 2019)

DIYLED said:


> I usually use cat5e with molded RJ45's. Bestlinknetware has a variety of lengths. In some situations it can be pulled with l-com brand covers taped over the connectors, and hardware stores have electrician's lubricant. But it is easier to pull non-crimped cat5e over long distances, tight openings, and turns. Another trick is cut one end off a pre-made cable. That reduces number of DIY crimps by 50%. Code requires data be separate from power in conduits. If it's not, it must be shielded to work, and shield connected to DMX ground at at least 1 end of each cable.


 *@DIYLED* You definitely wouldn't want to pull your shielded cables in with power AND bond both ends to ground. 
Induced circulating currents would burn / fuse the shield connections, likely fusing at the point of highest resistance / greatest voltage drop. 

In a multi circuit, 120 / 208 volt house light installation where most of the 96 outputs of a Strand CD80 dimmer rack were routed from the basement dimmer room to an attic junction box via three parallel runs of 2.0 or 2.5 inch I.D. rigid steel conduits; both ends of all three pipes were fitted with threaded on "Grounding bushings." 
Years later, the attic J-box was opened to facilitate an alteration. Surprise, surprise, surprise: 
Each of the three pipes contained the outputs of dimmers from one of the three phases. (no interphase cancellation of currents) Each pipe had contained one single 10 gauge TW, green jacketed grounding conductor. The grounding conductors had been bonded to their respective grounding bushings at both ends. ALL three of the green jacketed #10's had fused (burnt) at the attic ends melting as much of their green insulation at we could expose / see. The opposite ends were in the basement in a J-box within the poured concrete slab outside the dimmer room. I never ventured within the basement ceiling J-box to examine the lower ends of the three 10 gauge bonding conductors. 
Toodleoo! 
Ron Hebbard


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## DIYLED (Nov 28, 2019)

I had meant signal common, not earth ground. The DC ground, not the AC ground.

That is odd that the shared ground was on the same phase and I'm guessing the same gauge as the hots and neutrals. Even more strange that the green wires were carrying current and nobody noticed that something was wrong. At least they used a J-box and metal conduit. Otherwise would have burned down the whole building.


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## RonHebbard (Nov 28, 2019)

DIYLED said:


> I had meant signal common, not earth ground. The DC ground, not the AC ground.
> 
> That is odd that the shared ground was on the same phase and I'm guessing the same gauge as the hots and neutrals. Even more strange that the green wires were carrying current and nobody noticed that something was wrong. At least they used a J-box and metal conduit. Otherwise would have burned down the whole building.


 *@DIYLED* The building was built from its sub basement foundations on up beginning in late 1971 and approved for occupancy / final construction clean-up during the summer of 1973. All of the work was by union contractors including members of my local / home IBEW local. 

Whether by spec' or pure coincidence, the ou puts of all phase A dimmers were routed from basement to the attic within one 2 or 2.5 inch I.D. conduit. 
Likewise all phase B dimmers and phase C dimmers. 

At the basement / source end, all neutrals were connected to the common neutral buss. 
All conductors were 10 gauge TW to partially offset voltage drop over the length of runs. 

A suitable quantity of neutrals were included within each of the three conduits. 

Each of the three conduits were fitted with threaded grounding / bonding bushings on both of their ends. 

Each of the three conduits contained a single, TW10 gauge grounding wire bonded to the ground bushing at either end. 

The ground wire was NEVER intended to carry current except during fault conditions. 
When you (for whatever reason) enclose all of the conductors from the same phase, in the same conduit, with a random assortment of neutrals, you've created essentially an 'air core' transformer. 
Air cored transformers are more commonly employed at RF frequencies and transform FAR less power at 60 Hertz. 

None the less, transformer action / eddy currents / whatever, resulted in a ground loop comprised of the single TW10 gauge insulated conductor within each conduit looping back via the appreciably larger / much lower resistance threaded rigid steel conduit surrounding the insulated grounding conductor. 

In the survive the battle of the transformer coupled ground loop currents, the single 10 gauge was predictably the loser. 

Only trouble was: Apparently no one had troubled themselves to assess the odds. 

Go figure / who'da thunk. Only another of the many things innocently overlooked during inspections. 
Nobody was opening the basement box overhead within the poured concrete slab of the basement ceiling / 1st level floor. 

Had we not decided to utilize a spare dimmer, via spare conductors, NOBODY'D have ever noticed the flames that erupted and burned themselves out within a 16 x16 or 24 x 24 inch J-box anchored to a poured concrete attic wall approximately 8' above the attic floor. 

Upon opening the J-box we simultaneously saw the charred insulation, smelt the fumes AND felt the heat rising by convection and escaping from the attic ends of all three conduits. With all three conduits ending in the same box, the heat build up was appreciable. 
None of the other conductors were showing any evidence of overheating since they were loaded well within their ratings. 

At the time, I was a very junior IBEW member in my fourth or fifth term catching calls with Hamilton's IA 129. My boss within Hamilton Place was Head Electrician Tom Taylor; Tom had an excellent relationship with the IBEW foreman who'd built the building from undisturbed soil to the roof.

Rather than call in an electrical inspector, Tom chose to contact the IBEW foreman who visited the next time he was passing. 

Post much humming and stroking of beards, the decision was nade to replace the supplied solid cover with a cover band-sawed from from a sheet of heavy gauge expanded metal to simultaneously bar access to nosy fingers while leaving adequate open space for rising heat to escape. 

Years later, another CD80 / 48 slot / 96 x 2.4 Kw rack was installed in the attic, on the floor and anchored to the poured concrete side wall immediately below our infamous J-Box; a 3.5 or 4" run of conduit was installed up the wall of a nearby, 84 step, spiral stair to supply a 400 Amp, 3 phase, 5 wire feed to power the newly installed attic rack. 
To the best of my knowledge, the CD80 rack is still there, comfy and undisturbed in its happy little attic nest. 
Toodleoo! 
Ron Hebbard


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## DIYLED (Nov 28, 2019)

That's quite a story. Could you explain what the mistakes were? AC is not my specialty. It sounds like they should have used a thicker green wire if unbalanced and only grounded the conduits on 1 end. And maybe it's standard practice to balance phases through large conduits? 

I would have guessed that the magnetic fields of the hots would somewhat cancel the magnetic fields of the neutrals, and the voltage generated in the green wire would somewhat cancel that of the conduit. Maybe it's the random alignment of wires with imperfect cancellations that generated the transformer effect?


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## RonHebbard (Nov 29, 2019)

DIYLED said:


> That's quite a story. Could you explain what the mistakes were? AC is not my specialty. It sounds like they should have used a thicker green wire if unbalanced and only grounded the conduits on 1 end. And maybe it's standard practice to balance phases through large conduits?
> 
> I would have guessed that the magnetic fields of the hots would somewhat cancel the magnetic fields of the neutrals, and the voltage generated in the green wire would somewhat cancel that of the conduit. Maybe it's the random alignment of wires with imperfect cancellations that generated the transformer effect?


 *@DIYLED* I'll kick this can one more time and employ CB's 'Bat Call' to summon a few likely knowledgeable regular posters. 

Putting all of the outputs from any one phase in a conduit WITHOUT any of their out of phase mates equates to maximal accumulation of currents with essentially ZERO out of phase cancellation. 
Selecting neutrals at random meant they all came from one common neutral bar in the basement, which is normal and NO problem. 
When, once you're in the attic J-box, they were connecting 250, 500 and 1Kw loads to dimmers, keeping track of the hots but choosing any neutrals for their loads; some neutrals from one pipe serving as returns for hots in a neighboring, rather than the same, pipe. 

Bonding the single TW 10 gauge green jacketed grounding conductor was common practice but it was forming an insulated ground loop within the MUCH more conductive rigid steel conduit. With all of any given phase's live conductors in one conduit, induction would've been EXTREMELY high within the conduit itself leading to creating an excessively high induced voltage over the lengths of the conduits: Bonding each conduit's ends together with a single TW 10 gauge conductor was akin to shorting a butch battery / AC transformer with a single conductor not even close to being able to safely conduct the currents induced. 
Envision shorting your 12 volt car battery with a length of 18 gauge copper wire; you wouldn't want to be holding said wire in your fingers when you shorted out your car's 12 volt battery. 

If you own a pair of jumper cables, the wire gauges chosen aren't accidental. 'nough said. 

Perhaps I'll summon * @Jay Ashworth @Ancient Engineer @FMEng @TimMc @tjrobb* and *@MNicolai* to explain the inadvertent conspiracy of coincidences. (Possibly more commonly referred to as a "Cluster Phuque) 
Toodleoo! 
Ron Hebbard


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## FMEng (Nov 29, 2019)

I think the mistake was not keeping the neutrals paired with the hots in the same conduit. There is no issue with having all the loads from the same phase in one conduit, as that is commonly done. The vector sum of all the currents flowing through the conduit has to be zero to cancel the magnetic field and thus not inducing high current in the "one turn coil" made by the conduit and ground wire.

The National Electrical Code basically says all of the wires for any given load have to be kept in the same conduit. There is an exception for paralleling large conductors in multiple conduits, but there has to be one of each phase and neutral in all the conduits. So if the current code were correctly applied to that work, the melted ground wire would not have happened. The NEC makes wiring very safe when it's followed.


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## DanAyers (Dec 2, 2019)

There's some great responses above. I'd like to clarify a couple things I noticed which may help. 

Typically, All cabling between network ports, jacks, patch panels, and equipment must utilize prefabricated CAT6a, or better as required by the application, patch cables of appropriate length. Pre-fabricated cables are not run through conduits, only between devices.

When the cable is not simply between devices, and it goes through a conduit, you would not want to pull terminated cables through so the contractor will utilize a standard testing procedure. The contractor will test the cable to prove compliance with ANSI/TIA-568.2-D they will do so with the criteria specified in ANSI/TIA/EIA-568-C. That's a lot of jargon to say they will use a Fluke DSX-5000 or similar which will produce a report verifying the cables. 

As far as whether or not it's appropriate for your facility depends on how you will use your systems. For a new construction 750 seat theater I designed recently, I did install DMX from FOH to Stage and Electrics mainly for convenience but I also installed Cat6A cable for every foreseeable use (Sound, Lighting, Video, and IT) plus spares and extra empty conduit to add more.

At the end of the day there are no wrong answers, just be sure you're thinking through the application. I recommend a drawing, even if it's on a napkin. It's much easier to identify your needs when you can visualize the space. It's much easier to install during construction than retrofit.


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## BillConnerFASTC (Dec 2, 2019)

DanAyers said:


> also installed Cat6A cable for every foreseeable use (Sound, Lighting, Video, and IT) plus spares and extra empty conduit to add more.



I urge caution in installing infra structure for "future". I've seen and renovated many facilities with provisions for things that never materialized, not in the 25-50 years since installed. It may happen, more often in worship or pro than hs or university. And Cat6 whatever probably is not what you'll want in 10 years. Some spare conduit maybe.


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## DanAyers (Dec 2, 2019)

BillConnerFASTC said:


> I urge caution in installing infra structure for "future". I've seen and renovated many facilities with provisions for things that never materialized, not in the 25-50 years since installed. It may happen, more often in worship or pro than hs or university. And Cat6 whatever probably is not what you'll want in 10 years. Some spare conduit maybe.



You bring up a great point. My goal was to ‘be intentional’ about infrastructure.

And you’re right we’ve already moved from cat5e and fiber is getting cheaper every day; we don’t want to abandon infrastructure before its used.


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## RonHebbard (Dec 2, 2019)

BillConnerFASTC said:


> I urge caution in installing infra structure for "future". I've seen and renovated many facilities with provisions for things that never materialized, not in the 25-50 years since installed. It may happen, more often in worship or pro than hs or university. And Cat6 whatever probably is not what you'll want in 10 years. *Some spare conduit maybe*.


Posting in FULL support. 
Empty conduits (with labelled pull lines); they're NEVER cheaper to install than when they're routed and tied down to re-rod within poured concrete slabs. 
Conduits installed in poured slabs during initial construction are _extremely fast_ to install, time truly IS MONEY. 
Conduits ran in slabs normally run point to point by the shortest, most direct, routes possible. 
COMPARED TO: 
Surface mounted conduits requiring skill and FAR MORE TIME to install them "pretty", parallel, plumb, ninety degree bends, offsets and saddles, conduit straps, anchors, anchoring holes individually hammer-drilled into concrete, dust to be vacuumed up, yada, yada; so MUCH MORE time and labor. 
WORST CASE EXAMPLES: Adding conduits to floor boxes under seating in finished auditorium floors equates to labor, LABOR, *MORE LABOR*, down time, overtime and lost revenue. 
'nough said, I hope. 
Toodleoo! 
Ron Hebbard


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## ggooch (Dec 5, 2019)

Unfortunately when you are talking about installs, terminating yourself is the only way to go. Thank manufacturers can't screw up terminations? Think again. I routinely run into DMX and ethernet terminations with manufacturer issues.

Geoff


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