Quick question- what can I run in a cable raceway?

[soundtech193746]

hey all,
I’m doing some clean up work in a HS lighting booth and one of the ways I’m cleaning the wires up is with a cable raceway. I wanted to know if any problems could occur for running a extension cord wire, DMX, ETCnet through the same raceway. The distance in the race way is only about 5 feet. Is this okay or should I do something else?
Thanks in advance!! P.S- I attached an image of what I currently have done (not done yet)

 

[Les]

I would put the 120v in one raceway and the signal/data cable in another. Not only will this give peace of mind against potential interference, but think if that 120v cord shorted to your DMX or ETCnet. Probably would not end well. The NEC has a similar stance in not allowing low voltage in the same conduit as line voltage.

 

[Amiers]

Parallel is no good perpendicular is good. That’s the rule of thumb.

If you are going to run them in the same raceway separate it somehow.

 

[RonHebbard]

Parallel is no good perpendicular is good. That’s the rule of thumb.

If you are going to run them in the same raceway separate it somehow.

@baileypl @Les @Amiers Parallel in a common conduit, metallic or PVC or in Panduct or similar is not normally a problem IF signals are of similar types and levels. Examples: All balanced microphone level. All balanced line level. All low impedance speaker level. All 70 volt speaker level. I'm sure you've got the idea. Mixing unbalanced with balanced and microphone levels with speaker levels are definite no, no's. Power wiring and signal level in the same raceway is DEFINITELY verbotten.
Toodleoo!
Ron Hebbard.

 

[JD]

Although this is a cosmetic raceway that is not part of the building and simply used to organize the room, a line voltage extension cord needs to be the odd man out. Current spikes in the AC cable can induce voltages in the other cables. Ironically, the surge suppressor at the end makes it worse! When the MOVs clamp a surge, the wiring feeding the suppressor see a current spike, which induces a small EMP which will get picked up in the signal cables. May or may not be enough to cause a problem, but life has enough problems. No point dancing on a mouse trap.

 

[epimetheus]

While I agree with the comments above in principle, practically I see no issues with what you've done. We all know that cables of different signal types are going to be mixed together as you approach the end devices, especially under a desk. The problems with running power and signal cables parallel to each other are exacerbated by the length they are in parallel. Short distances like what you've got here don't concern me in the slightest. Try to keep them separate as much as possible, but I wouldn't jump through hoops under a desk.

Also, I think the NEC does have an exception to running low voltage and line voltage in the same raceway. If the low voltage signal is related to what the line voltage is supplying power to, and the low voltage cable has a voltage rating appropriate for the line voltage, then the low voltage is allowed to occupy the same raceway. The situation I always think of for this is 0-10V dimmable fluorescents, since the low voltage is controlling the ballast supplied by the line voltage, you're allowed to share a raceway.

 

[RonHebbard]

View attachment 15553 View attachment 15554 View attachment 15555
hey all,
I’m doing some clean up work in a HS lighting booth and one of the ways I’m cleaning the wires up is with a cable raceway. I wanted to know if any problems could occur for running a extension cord wire, DMX, ETCnet through the same raceway. The distance in the race way is only about 5 feet. Is this okay or should I do something else?
Thanks in advance!! P.S- I attached an image of what I currently have done (not done yet)

@baileypl I'd draw the line at water, hot, cold, or chilled along with pneumatics and natural gas.
Maybe that's just me, I never was a major risk taker.
To be a trifle more serious, Panduct used to offer products with a longitudinal dividing wall to accommodate a degree of physical separation covered by one snap-on cover spanning the full width. I used to employ those products in AC servo automation drive applications and found them quite useful along with similarly partitioned plastic / nylon drag-chains. In the case of the drag-chain products, our shop even ran compressed air for pneumatic caster jacks within the same compartmentalized drag chain as AC servo motor drives, DC brakes, limits and resolver cables.
Toodleoo!
Ron Hebbard.

 

[soundtech193746]

Although this is a cosmetic raceway that is not part of the building and simply used to organize the room, a line voltage extension cord needs to be the odd man out. Current spikes in the AC cable can induce voltages in the other cables. Ironically, the surge suppressor at the end makes it worse! When the MOVs clamp a surge, the wiring feeding the suppressor see a current spike, which induces a small EMP which will get picked up in the signal cables. May or may not be enough to cause a problem, but life has enough problems. No point dancing on a mouse trap.

Excuse my ignorance, but I’ve seen in different installs, power strip wire being ran with data cable. By being ran, I mean a small 5 foot run with cables ties. This is just for cosmetics. I don’t know much about power, but does it matter what gauge/shielded level of the cable is? And also, what would be the best way to do this right?

 

[soundtech193746]

While I agree with the comments above in principle, practically I see no issues with what you've done. We all know that cables of different signal types are going to be mixed together as you approach the end devices, especially under a desk. The problems with running power and signal cables parallel to each other are exacerbated by the length they are in parallel. Short distances like what you've got here don't concern me in the slightest. Try to keep them separate as much as possible, but I wouldn't jump through hoops under a desk.

Also, I think the NEC does have an exception to running low voltage and line voltage in the same raceway. If the low voltage signal is related to what the line voltage is supplying power to, and the low voltage cable has a voltage rating appropriate for the line voltage, then the low voltage is allowed to occupy the same raceway. The situation I always think of for this is 0-10V dimmable fluorescents, since the low voltage is controlling the ballast supplied by the line voltage, you're allowed to share a raceway.

Do you think I should change anything or is it okay? The wires are pretty thickly shielded. Thanks for the reply !

 

[RonHebbard]

Do you think I should change anything or is it okay? The wires are pretty thickly shielded. Thanks for the reply !

@baileypl Personally, I would use divided Panduct, or an equivalent brand, with a longitudinal divider and run the power in one side by itself. If I was forced to run the power in a section with other wiring, my first choice would likely be 70 volt speaker lines, if I had any to include, followed by low impedance speaker lines. I would NEVER intentionally route power with microphone level wiring, balanced or unbalanced. You may twist my arm into running adjacent with +4 balanced audio but I'd neither be happy nor go home proud of myself.
Toodleoo!
Ron Hebbard.

 

[soundtech193746]

@baileypl Personally, I would use divided Panduct, or an equivalent brand, with a longitudinal divider and run the power in one side by itself. If I was forced to run the power in a section with other wiring, my first choice would likely be 70 volt speaker lines, if I had any to include, followed by low impedance speaker lines. I would NEVER intentionally route power with microphone level wiring, balanced or unbalanced. You may twist my arm into running adjacent with +4 balanced audio but I'd neither be happy nor go home proud of myself.
Toodleoo!
Ron Hebbard.

How much does Panduct typically run and where can I find it?

 

[sk8rsdad]

How much does Panduct typically run and where can I find it?

Electrical and electronics wholesalers and retailers, some big box retailers, pretty much any shop that does commercial cable management can source it. Price varies depending on the model and quantity. Google can help you find a local supplier and they can provide a quote.

 

[RonHebbard]

Electrical and electronics wholesalers and retailers, some big box retailers, pretty much any shop that does commercial cable management can source it. Price varies depending on the model and quantity. Google can help you find a local supplier and they can provide a quote.

@baileypl Panduct is a Panduit product / brand name available in different widths, different depths, longitudinally divided and non-divided and also in different colors with grey being the original and most commonly stocked. Distributors routinely stock in 4' lengths, some may have longer lengths available depending upon the actual brand they stock. Cuts easily with a fine (32 TPI) hacksaw and mitres nicely for neat corners.
NOTE: When ordering, snap on covers are not normally included thus remember to order covers.
Toodleoo!
Ron Hebbard.

 

[JD]

Excuse my ignorance, but I’ve seen in different installs, power strip wire being ran with data cable. By being ran, I mean a small 5 foot run with cables ties. This is just for cosmetics. I don’t know much about power, but does it matter what gauge/shielded level of the cable is? And also, what would be the best way to do this right?

The key takeaway is that wires do not have to be electrically connected to transfer power. Best example is your car radio antenna has an electrical signal induced in it by another piece of wire (the transmitter) many miles away. Low frequencies don't travel very far and need long lengths to induce anything of significance. AC is pretty low at 50/60 Hz. Still, transient spikes on an AC line tend to be much higher in frequency and may cause problems. Do I think a 5 foot run will cause a problem for you? No. As you pointed out, people do it all the time. Can it be capable of causing a problem? Yes. In performance based operations, if a problem is going to occur, it will usually occur at the worst possible time! The best practice is to try to eliminate all potential problems, thus reducing the list of variable to track down when things do go wrong.

 

[Footer]

So, every FOH snake that has power taped to it is no good? Every loom that has power and DMX taped to it is also no good? Yes, I get the theory, but in practice I have never seen an issue. I got cable w/ power, signal, and data all in one jacket and it works fine.... and been like that for 15 years.

 

[gordonmcleod]

In most cinema booth i use the wiremold 4000 raceways that have a optional barrier that seperates it into two divisions one is low voltage /data/audio the other is line voltage
At least in Canada one cannot have line voltage in the same raceway as lowvoltage
https://www.legrand.ca/wiremold/rac...ay/4000-large-raceway/4000-large-raceway.aspx

 

[FeRDNYC]

The key takeaway is that wires do not have to be electrically connected to transfer power.
[...]
In performance based operations, if a problem is going to occur, it will usually occur at the worst possible time! The best practice is to try to eliminate all potential problems, thus reducing the list of variable to track down when things do go wrong.

+1. When the MTA embarked on their ambitious project to bring cellular service to all of NYC's 200+ subway stations, an undertaking which involved cabling the entire length of the subway system and installing cell "towers" at platform level in the underground stations, each new equipment install was connected up to two completely separate pipes, housing (as labeled) "RF CABLE" and "POWER AND FIBER". Because they want the system to actually work, and stay working.

(This also highlights one great advantage of optical fiber: It laughs in the face of EMI. But if you're using standard electrical cabling, induction is the enemy.)

Back in the 1990s, when I was working for the company that ran AOL's dialup network, one of our engineers obtained a measurable improvement in performance/reliability for our modem equipment racks just by re-cabling them so that all of the power lines ran up one side of the cabinet, and all of the data (ethernet, serial comms, telco digital drops) ran up the other side. And that's total last-mile (last-seven-feet, in fact), though in an admittedly high-capacity situation.

 

[Collin L]

I know that I've seen raceways that have both Stagepin outlets from the dimmers, and 5-pin DMX outlets. Out of the end of the raceway there is only 1 bundle carrying both the 20 dim lines and the 2 DMX runs. Are we saying that these installations don't comply with the NEC Standards?

 

[FeRDNYC]

So, every FOH snake that has power taped to it is no good? Every loom that has power and DMX taped to it is also no good? Yes, I get the theory, but in practice I have never seen an issue. I got cable w/ power, signal, and data all in one jacket and it works fine.... and been like that for 15 years.

Not "no good". Just suboptimal. It'll work fine, often for years or decades as you've seen... until it doesn't. You may never encounter a situation where it "doesn't", in practice. Or, the problems may not be enough to be noticeable. (Ethernet, for example, will manifest EMI problems as bad packets. But TCP automatically retransmits, so other than a small percentage of bad packets in the interface statistics you'd likely never even see any effects from the interference.) Or you may end up in the situation where that combined power+audio run starts buzzing only when someone plugs a vacuum cleaner into the circuit (which of course they shouldn't do), whereas having the power line separated from the audio would prevent the vacuum cleaner from creating noise on the line.

 

[MNicolai]

Signal separation is more critical for large bundles of cables, higher current power runs, and primary infrastructure cabling. In practice, you have to be pretty reckless to break something though. Coiling your analog audio snake around a UPS, putting kinks or sharp bends in your data cables, etc. Portable cabling at racks, booths, on-stage, are less forgiving in that they aren't shielded in conduit but the parallel distances are much shorter. It's more important that your electrician keeps the cable groups separated when they pull the wire in the walls and ceilings so you can afford to play it fast and loose on-stage without disruption.

Now if you use untwisted THHN for speaker wires out to your speaker clusters and bundle all your THHN together, there's actually a fair chance if you turn the system up and mute the right cluster you'll hear the right signal out of the left cluster. Twist the THHN pairs together and that problem goes away as far anyone can hear. Again though -- more a problem for long distances. This is the kind of problem that will present with +50' of parallel bundled untwisted wire. You'll be hard-pressed to notice anything at all at +10'.