# Floor pocket requirements



## mstaylor (Nov 4, 2009)

Our local civic center is tearing the existing floor out of the arena to the dirt and replacing it. We will be getting many more floor pockets than we have now with what we actually need in them. I will be adding a mic send to each pocket and comm in selected pockets. I need to spec the wire size and connector type for each. I assume that the wire type will be the same for both mic and comm sends but wanted to ask somebody that knows more than me. We are using Clear Comm headsets. 
They are once again asking the light guy to spec sound stuff.


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## epimetheus (Nov 4, 2009)

The cable is generally the same for mic and comms. Or rather, the Clearcom party line system is designed to run on standard mic cable. The mic connectors will be panel mount female 3 pin XLR's. I'm currently a fan of the Neutrik DLX series. Do you use 2-channel belt packs or single channel? If you use single channel packs, the comm connector will be a panel mount male 3 pin XLR. If you use 2-channel packs, then you'll need a 6 pin XLR. If do use 6 pin XLR, be careful of which pin orientation you need, there are 2 different ones, Switchcraft and standard (I'm not sure if the standard config has a particular name or not).

One thing to consider with comm systems - if you are using single channel belt packs you might want to install an A and a B channel in your floor pockets. That way to can have some seperation and still use single channel packs.

One other thing - clearcom packs have male and female connectors on them, so in theory your comm connectors in your floor pockets could be either male of female. Generally speaking, a male connector is considered to be an output connector, a female an input. For this reason I like my comm panel connectors to be male. The outputs on the back of the clearcom main stations are male.


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## museav (Nov 4, 2009)

Do you have any input into what the floor boxes are? If you let the Electrical Engineer select them you may not be happy as they often specify boxes that require custom plates for anything other than Edison receptacles or RJ jacks or boxes that do not handle connectors with any length very well or that have to have the lid open when in use. If the boxes are on grade or in slabs you will probably have to look at a backbox and insert arrangement, you won't be able to use typical stage boxes where they directly contact earth or concrete. And in an arena setting you may have to consider the weight the box can support. Something like this, FL-H20-1, can be nice where you have a number of services and require heavy duty load ratings.

You might also want to detail the box and the related conduit serving it. Especially if there are multiple compartments or different size plate areas, it can be important to get the right conduit coming into the right part of the box. Having the power come in where the mic jack will go and the mic line come in the power receptacle section can lead to problems.


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## derekleffew (Nov 4, 2009)

Were it me, I'd also strongly consider installing CAT5/5e/6 in every floor pocket, running back to a patch panel in the control room.


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## fredthe (Nov 4, 2009)

I second the suggestion for CAT5+ cable at each pocket, terminated in a patch panel. Given the wide variety of things that can be run over it (Video, Digital Snakes, DMX, in addition to normal computer or phone applications) it's a good way to plan for future unplanned needs.

-Fred


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## jkowtko (Nov 4, 2009)

Anything you can put in there now will cost you ten times as much to put it in later 

I'd add enough multi-strand to handle a couple more mic/return channels in each pocket, as well as cover in-wall breakages.


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## cdub260 (Nov 4, 2009)

Assuming of course, that you have some spare capacity in the floor pockets, have them run as many extra, empty conduits as they can for future use. Odds are that at some point down the road, you will need those extra conduits.


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## mstaylor (Nov 4, 2009)

We are planning to to have a 50 amp and a 60 amp connector in each box. There will be water and drains in some of them. We also are planning for a mic line in all the boxes, headsets in part of the boxes, 110 receptacles in all boxes, and cat 5 in all of them. We finally convinced them to inconnect the boxes in case we need to pull something extra between them. Everything is going to return to box backstage. It isn't in the bid but when they pull everything to the sound booth, I am going to run a 5 pin for DMX. I didn't see any need for DMX in the boxes.


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## Anonymous067 (Nov 4, 2009)

Perhaps you could elaborate on the water/drainage in stage boxes...and possibly the 50-60 amp in each one?? Not quite clear...


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## mstaylor (Nov 4, 2009)

We have two types of temp boxes that feed from the floor pockets, one is fifty amps and has a strange plug, the second is a five pin twist that happens to marry to many motor controlers. We are putting both sizes back in the new pockets so we don't have to buy a ton of new breakouts. 
The water/drain is put in for trade shows. We have some shows that display hot tubs and are currently having to make long runs to water to fill and drains to empty. We figure to put this ability in a few of the boxes to cut down on the mess they make. 
I forgot, we are also putting phone and cable in the boxes for the same reason. We have been dropping phone lines and cable hookups from the ceiling and it looks terrible. Now we can tie them in at pockets for TV and credit card machines. 
Also we will be putting in a central trough to lay show snakes in to eliminate yellow jackets. People don't seem to be able to pick their feet up enough to clear them.


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## Anonymous067 (Nov 4, 2009)

You put phone and TV in so when somebody says "I want a TV on stage" you can say, plug it in here. (as opposed to running 500 feet of cable).

I'm pretty sure I'd request the water stuff in a separate box as the electrical...pretty sure there's a code regarding this?


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## mstaylor (Nov 4, 2009)

You have to remember we do a lot of conventions and trade shows which is why we have the phone and cable. I have another building I work in that has the water/drain in the floor pockets.


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## Lightguy48 (Nov 7, 2009)

One recommendation I have is make sure they're deep! I can't count the number of times where I've been in a building and the pocket was too shallow, the connectors stick up and get stepped on breaking the connector or the mounting plate.

Make certain the pockets are deep enough that physical connector is below grade when plugged in.

I certainly second the CAT5 and RG6 coax. Also, make sure any spare conduits have pull string installed for when additional wire is installed. I would at a minimum have double-gang pockets because with the correct plate a double-gang box will support up to 12 cables, 6 per gang.


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## mstaylor (Nov 7, 2009)

I concur with all your points. Our current pockets are deep enough but require them to be partially open to allow wires in and out. I have fought this since we opened in late 
'79. I was insistant that they have some means to allow cable entrance but still be flat. I gave them a list of pockets that would work but I don't know what the final choice is. The same goes for the center trough. I want it to be able to be entered and exited at any point in the run.


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## Chris15 (Nov 7, 2009)

Adding to what others have said, you need to build a degree of future resistance in. Don't install Cat 5 or 5e, go 6 or 6a - it will give you better longevity. I wouldn't bother with phone cabling, just add another Cat 6 or two...

I'd seriously consider fibre connections - some of these trade shows have the bandwidth demands to warrant it.

I'd spec comms to every pit, otherwise, sure as anything on the first show you'll want it at one of the other pits... I'd prefer dual input tie lines (back to a patch panel) and an output also. Run it all in AES spec cable. Consider also 3GHz or 4.5 GHz coax drops to each box to support SDI video etc as may be needed, also being useful for MADI, word clock, etc.


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## mstaylor (Nov 8, 2009)

Chris15 said:


> ...I'd spec comms to every pit, otherwise, sure as anything on the first show you'll want it at one of the other pits... I'd prefer dual input tie lines (back to a patch panel) and an output also. Run it all in AES spec cable. Consider also 3GHz or 4.5 GHz coax drops to each box to support SDI video etc as may be needed, also being useful for MADI, word clock, etc.



You are now over my head. I have the whole light guy, not sound guy, thing going on.


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## museav (Nov 9, 2009)

What Chris is basically saying is suggesting to use digital rated cable for audio and video. Cable rated for AES audio or SDI/HD-SDI video will work for analog audio and video as well and using it leaves open the option for digital signal use.

I want to reiterate for others, convention center type floor boxes are very different than stage floor boxes as far as size, connectivity, load capacity, etc. They typically have to handle all the utilities that multiple displays or vendors may require (communications, power and in some cases, water, sewer (thus the drain) and perhaps even gas. Yet they have to be able to be driven over by forklifts, cars, etc., which is why terminations on posts and walls where possible rather than in the floor is quite common.


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## mstaylor (Nov 9, 2009)

Thank-you and that is a good synopsis of what is unique to a CC floor pocket. 
I am being asked to specify the exact connectors and cable to be used, any suggestions?


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## FMEng (Nov 14, 2009)

I would also add Cat 5, 5e, or 6. It can be used for data (internet and LAN), line-level audio, intercom, telephone, and medium resolution video. 

I would also put a few single and multi-mode fiber optic cables in. Many of the digital audio snakes are using fiber, and it can also be used for high resolution video, wideband RF (like TV and satellite IF).

If you add those to the system, you'll seldom ever have to run anything over the floor. It's cheap and easy to put it in now. Hard and expensive later.


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## Chris15 (Nov 15, 2009)

Ok so exact cables and connectors...

Say we do 2 female and 2 male audio line per pocket. Either or both male can be used for comms by relevant patching. That makes nicely for a 4 way audio snake. Something like Eurocable SSAD04C would work nicely. Connectors - Neutrik NC3FD-LX for female, NC3MD-LX for male. If you are doing the assembly, append -M3 to the end fo each for pretaped threads, If someone else is, that bit is optional.

Cat 6 - whatever the contractor wants to use. Connectors: Neutrik Ethercon. (Can Brad or someone comment on the mating of a Cat5e ethercon into a Cat 6 ethercon socket - they look to be opposite genders, if so great work Neutrik.)

Coax - Belden - 4.5 GHz. I don't have the part number handy. Connectors: Neutrik NBB75DFIB-P. I wouldn't be sure of performance from a solder connector at 4.5 GHz...

RF - RG6 with F connectors (which can be a right pain)

Fibre - consult someone who knows what they are talking about. Neutrik Opticalcon will take a standard LC connector as well as the rugged Neutriks. Make sure they clearly mark which is single mode fibre and which is multimode (get both installed)...http://www.neutrik.com/fl/en/video/210_t2_295026140/NBB75DFIB-P_detail.aspx


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## mstaylor (Dec 4, 2009)

OK, we have finalized what is going in the pockets. They will be two section pockets, one side high vo;tage, the other low voltage. The water and drains will seperate pockets dedicated to just this function. The only problem I face now is my bosses say it will be bid to electricians to do all the work. I try to explain that it should be bid as the electricians setting the pockets, pulling everything and terminating the high voltage side. Then a second contractor should do the terminations of all the low voltage componets. They seem to think the electricians can do it all. I try to explain they aren't really qualified to do that and it is like hiring a carpenter to paint your house. He can do it but not well.


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## museav (Dec 4, 2009)

I would agree with you, although in some areas of the country the Electricians do routinely have people who are well qualified in and experienced with low voltage cabling. But that is not true in many areas such as here where Electricians are typically not that experienced with many low voltage cabling issues and there is even a separate Low Voltage Contractor's license.

I often argue that the low voltage cabling and terminations should be part of any related systems work in order to have one point of responsibility. If you separate the cabling and systems work you split the responsibility, if something doesn't work or works poorly it can become an exercise in finger pointing with each side blaming the other. If a mic or other connection does not work the first step becomes deciding who is responsible and if you go the wrong way you may end up paying for it, quite literally as in paying for a service call by the party who it turns out was not responsible. There is also the issue of how do you address the termination at the sound system, you may have to include some intermediate termination so the E.C. wires from the floor boxes to that point and the audio contractor from that to the sound system, thus neither directly impact the other's work. Again, in some areas of the country it is common for the Audio Contractor to wire the rack with connectorized pigtails and the E.C. to wire to wall plates, then you plug the rack into the wall plates.

If nothing else, if they do decide to include the low voltage cabling in the Electrical Contractor's work then make sure that the specs include extensive testing and documentation of the cabling, something that clearly shows the cable has been thoroughly tested and that the E.C. takes responsibility for the work.


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## mstaylor (Dec 4, 2009)

The cabling is going to terminate in a bay system. I will actually have many mic imputs than exist on my board, the next expansion. I will be able to connect whichever floor pocket input to whichever fader in the patch bay. I am supposed to get an A&H to replace my Mackie and I hope to get more faders so I will have to do less repatching.


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## Footer (Dec 4, 2009)

I used to work for an electrical contractor specializing in communications cabling. They did not do too much on the sound side of things, mostly fiber and phone/data. In Illinois you actually go paid more to do high voltage work then low voltage work. They claimed it was due to the hazard involved in high voltage work. 

Odds are it will be the same company but two separate guys. IBEW has a different classification for low voltage electricians and they tend to stick to that. Most the guys who do low voltage work do it because its a bit easier work and your odds of being up on a pole are less. I would not worry too much about it.


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## museav (Dec 5, 2009)

Footer said:


> I used to work for an electrical contractor specializing in communications cabling. They did not do too much on the sound side of things, mostly fiber and phone/data. In Illinois you actually go paid more to do high voltage work then low voltage work. They claimed it was due to the hazard involved in high voltage work.
> 
> Odds are it will be the same company but two separate guys. IBEW has a different classification for low voltage electricians and they tend to stick to that. Most the guys who do low voltage work do it because its a bit easier work and your odds of being up on a pole are less. I would not worry too much about it.


That sound like you are addressing the differences between different geographic areas. In some areas, especially those where IBEW and Unions in general are very strong (New York, Philadelphia, Chicago, St. Louis, etc.), the situation you noted is often true and Electrical Contractors often have people who specialize in low voltage systems cabling. But in other areas, such as here in Georgia, this is often handled by two different parties and many Electrical Contractors do not work in low voltage or only work in certain areas.

Part of that is likely because not only is Georgia a 'right to work' state but also has separate licensing for Low Voltage Contractors, with a further four different classifications within that; General, Telecommunications, Alarm and Unrestricted (which covers all of the other three areas). So someone could be a licensed Contractor for telecom (voice/data) and/or alarm but not for audio, which falls under the General heading. And unlike some states or proposals put forth in other states, a licensed Electrical Contractor is not automatically licensed for low voltage work, they are separate licenses.

What is common here and in many other areas is for an Electrical Contractor to contract for all Electrical and Low Voltage work and then subcontract the low voltage part of the work to a separate Low Voltage Contractor. Part of that approach is a legacy of the old CSI Master Format that used to include the low voltage work in the Electrical specifications (which was never intended to be a division of work but typically had that effect) and part of it is due to overlap and coordination related to raceway, conduit, boxes, etc., which are typically handled by the E.C.


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## Chris15 (Dec 5, 2009)

A semantic correction here...
We don't deal with High Voltage, that's generally defined as >1000 Vac or > 1500 Vdc. What we're talking about is Extra Low Voltage, <50 Vac or <120 Vdc, and low voltage being the range between those two...
(per IEC definitions)


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## mstaylor (Dec 5, 2009)

Chris, you are correct, I should have put high voltage in quotations marks. The "high voltage" side is 110v and 208v three phase. The low votage side is really sound and communications. 
Now we are like Georgia, there are two union cntractors with-in 60 miles and they specialize in big state contracts including schools and trafic devices. The last tiime I dealt with one of them they wired strip lights incorrectly. They had 1,2,3,4, wired together and didn't understand why that was a problem.


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## museav (Dec 5, 2009)

Chris15 said:


> A semantic correction here...
> We don't deal with High Voltage, that's generally defined as >1000 Vac or > 1500 Vdc. What we're talking about is Extra Low Voltage, <50 Vac or <120 Vdc, and low voltage being the range between those two...
> (per IEC definitions)


Chris, a good example of geographic variations. That may be true for you but for the US NEC defines the electrical classifications and state licensing defines the related licensing. Unfortunately, NEC does not actually define "low voltage" and this causes much confusion. NEC instead addresses multiple applications and classes under several different Articles that would traditionally be considered to address "low voltage" circuits. In fact one can even argue that based on the NEC anything under 600VAC is not high voltage and therefore is low voltage.

However, your comment does bring up one of the issues commonly encountered. Many amplifier outputs are well above 50VAC or even 120VAC, thus a voltage not much different than AC power. Many amps can also output current near or at that of many power circuits. For example, if an amp delivers 2,000W into 8 ohms that is 126VAC and 16A, in effect equivalent to a typical branch power circuit. Some amplifier outputs do indeed technically have to be treated just like power but in many cases there is a gray area regarding such issues. For NEC you actually have to look at what the amplifier says is the applicable wiring classification and that is not always information that is easy to find, you typically have to look at the back of the amp itself or find a good enough picture of the rear panel so that you can read the rating.

It is probably pretty obvious that can be a confusing and easily misunderstood subject even for electrical and audio pros, much less for DIYers.


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## mstaylor (Dec 5, 2009)

In my experience locally, if the electrician can't wire nut it, lug it or bug it, they probably need to leave it alone. When it comes to soldering or cutting down a cat5 cable they are lost. I will say that is a generalization and probably not entirely fair but my concern is some guy in there trying to build a patchbay with all that soldering and no clue what it does or why. This is how I got strips wired in groups of four. It was certainly within his nowledge base but he had no understanding what he was wiring or how it worked so he couldn't apply his knowledge of troubleshooting and foresee the problem before it was completed.


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## Chris15 (Dec 8, 2009)

museav said:


> Chris, a good example of geographic variations. That may be true for you but for the US NEC defines the electrical classifications and state licensing defines the related licensing. Unfortunately, NEC does not actually define "low voltage" and this causes much confusion. NEC instead addresses multiple applications and classes under several different Articles that would traditionally be considered to address "low voltage" circuits. In fact one can even argue that based on the NEC anything under 600VAC is not high voltage and therefore is low voltage.
> 
> However, your comment does bring up one of the issues commonly encountered. Many amplifier outputs are well above 50VAC or even 120VAC, thus a voltage not much different than AC power. Many amps can also output current near or at that of many power circuits. For example, if an amp delivers 2,000W into 8 ohms that is 126VAC and 16A, in effect equivalent to a typical branch power circuit. Some amplifier outputs do indeed technically have to be treated just like power but in many cases there is a gray area regarding such issues. For NEC you actually have to look at what the amplifier says is the applicable wiring classification and that is not always information that is easy to find, you typically have to look at the back of the amp itself or find a good enough picture of the rear panel so that you can read the rating.
> 
> It is probably pretty obvious that can be a confusing and easily misunderstood subject even for electrical and audio pros, much less for DIYers.



There is a reason I went back to the IEC not referring to AS anything, as in fact your NEC is non compliant with the international definitions of the IEC.

The comment about power levels is particularly true if 100v distributed line systems are involved. I believe the rules for LV communications (which is what speaker cabling would fall under) down here are such to require double insulation. That kicks in at 50 V AC RMS.

Folks let's not delude ourselves here... Speaker wiring can kill you almost as easily as mains wiring...


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## museav (Dec 8, 2009)

Chris15 said:


> There is a reason I went back to the IEC not referring to AS anything, as in fact your NEC is non compliant with the international definitions of the IEC.


I certainly will not try to argue that all of the NEC makes sense or that it agrees with any other accepted standards or practices. Even the experts can't seem to agree on some of the issues and compliance is often up to an individual's interpretation. But it is what we have to work with here in the US.


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## Gmont (Dec 8, 2009)

I don't think anyone has said this yet but the last time I installed a Clear-com system their manual said that you should not run less than 20awg w/ shield. Most of the companies out there have an installation manual that will tell you what their wire requirments are and suggestions of wire.

G


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