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Posted By: Kumba Best Backboard Wiring Practices and Standards? - 07/18/07 06:38 PM
So since I do now know everything and am willing to freely admit it, I figured that I would ask those here with more experience and knowledge then me to share some of it. As always, thanks for your input if you choose to leave some smile

Intrigued by the post over on the Phone Booth about botched backboard installs, I started to wonder what a proper backboard install should consist of.

Here are some general rules and/or guidelines that I know (or think I know) for back-board set-up. This just comes from seeing how different people have ran them.

-Use a pre-built frame or 5/8 Plywood.
-Spacing between blocks should be even with a consistent distribution/arrangement.
-The blocks should line-up (be level) and not look like polygons.
-Distance between the blocks should be roughly the width of the blocks.
-There should be two Mushrooms above each block (or row) of 66 so that the shaft of them lines up with the edges of the block.
-Rows should be no longer then 4-5 blocks
-The In-House wiring runs under the block and punches in on the right side.
-Cross Connects punch on the left and run up the row to the mushrooms, then across, then back down to the other blocks.
-D-Rings used on cable bundles

I'm sure some (or potentially all, as i'll find out) are wrong.

If you have your own school of thought or just want to correct me feel free. Thanks.
While most installs I've done are where I have existing wiring and the customer just wants to "make do" I clean them up as much as possible. New install I price with backboards, which you install on a sheet of plywood, 5/8 is good painted to room color, or whatever the customer prefers. I don't always use a Green backboard since I've never found a single green and most my installs are small. Old practice called for Red for the KSU, but since most all systems are more PBX in feature than the old 1A2 stuff the backboards were based on I use PBX field of purple. Order on top left to right green, purple, and yellow. below that a row of single or double white distribution rings, depending on the size of the job. Below those the blue station backboards properly labeled by jack location, intermediate terminal location or what every is needed. Makes for a neat job that anyone who knows what the colored backboards means can just walk in and go to the correct location to do their job. No fuss as all is equally spaced from the factory. If I get my way, which I don't always, no new install with out colored backboards.
I really hate unpainted backboard , I did one recently where the GC installed two 4x8 sheets of plywood but refused to paint

I'd already bid the job with the understanding that the backboard would be supplied , customer said don't bother painting

I went ahead and painted anyway ..no up charge

I never use store bought backboard, usually 4x8 3/4 " ply
painted with $5 a gal "oops" paint in a neutral color

layout varies depending on what all gets mounted

sometimes use mushrooms , sometimes 1/2 d ring
I like those premade backboards with the brackets, but most jobs are coming in after someone's mess, with a backboard already on the wall. The job I am doing now has a painted backboard in place, and I just removed all the old blocks and put mine in, properly spaced out. On this job, I am not doing the system, just the cabling. I hope the phone system guy does not make his stuff a mess smile
As far as punching down house cable on one side, and cross connect on the other, do you mean on the same block, or do you mean the frame as a whole?
Bill: Thanks for the info. I have never used the color codes before. Most of my installs are only 1 or 2 66 Blocks for stations and 1 66 block for CO lines. I can only remember seeing a handful of backboards that were color coded. These were multi-thousand pair installs.

Skip: The way you described it is how I see a lot of backboards installed around here.

Jeff: The way I used it in my original post was on the block itself.
I have a deal, the lumber company cuts my boards to order in 3/4 Aruco it keeps the 3/4" hex head screws from coming out the back like they would in 5/8" material. It's about 9 plys of material and holds screws better than plywood. I usually order a half or full sheet and keep the other cuts as 2x2's or 1x3's or whatever. I try to match the wall or use some whitish color paint, somethimes somebody else's wall color as I get paint by the quart and use a 4" roller to paint the backboards. My local Sherwin-Williams store gets about $11 a job for paint if I mix.

How the board lays out is purely dependent on type of system and where the KSU and patch panel goes. If the KSU ends up behind or underneath the patch panel on the right side of the board, then the house cable tends to end up immediately to the left of the patch panel and the KSU 66 blocks to the left of the 110 block house cable. In that case, the KSU cables terminate on the left side of the 66 blocks and the jumpers come off the right side.

Blocks tend to get mounted 4 high because that's what fits on a 48" board. Yes, I never even thought about it, but I mount my second row of blocks 6" away from the edge of the first one, so plastic parts have 2" without the ears between them. If I have two rows of 66 blocks for a distribution, like a PBX, the left side blocks get terminated on the left and the right side get term'ed on the right so the jumpers fan from the center of the group and out to the house cable.

If I'm using S20-B's, I'll put only a single mushroom at the top and center of the row, about 1" above the top of the block. Most times I'll use a "D" ring to feed the 110 block. With house cables mostly being Cat-5e I try to stick with 110 terminations on the house cable and I still use 66 blocks on the KSU with bridge clips.
If it's a low-budget job or it goes into a patch panel, then I'll break down and eliminate the bridge clips and terminate on both sides of the 66 block.

I never worked for Bell and at GTE we never used colored backboards. I trained in a C.O. and PBX environemnt anyway, so we didn't do those fancy colors, in the C.O. our blocks were all maple and black and we had no backboard, and in the field, we were building the PBX's and sometimes we even got to use them there fancy 66 blocks and a punch tool instead of a wire wrap gun.

Last winter, I did an installation where the cable company telco had to mount a block. I had my first row of 4 blocks and a space to the left for the second row for my PBX. I told the guy to mount on the bottom left exactly level with the 4th block and 6" away. Of course he didn't and I pointed that out to him when I walked back into the room. I left to check on something and when I came back a second time it was still unmoved and he was doing something else. I just reached into my toolcase, grabbed a drill and excused myself and unhooked the block. He said "that's phone company property" and I suggested what he could do with his wannabe phone company. I then proceded to run all my C.O. jumpers and half tapped them with written instructions and left. The guy was unhappy but it got done right.

Of course, if you are not the first guy in, all bets are off. Then, I try to build a board off-site and hang it like a picture.

Carl
The key is to make it look neat. The colored backboard system was great in its day, when systems used 25-pair cables to and from the stations and KSU's, and a whole closet was needed just for a small 1A2 system.

These days, I paint the back board gray if it's in the electrical equipment room, and white if it's in a closet. Since a lot of my work is chasing a previous "expert" I generally rip out what's there, and reterminate as neatly as the cable slack will allow, so the left-side, right-side question is a random one.

I use minimum 3/4 inch plywood, and if the existing backboard is less than that, and I can do it easily, I scab on a second layer. I can only get 1" drywall screws at one lumber yard near me, (not available at Home Depot) and I use them exclusively to mount stuff.

I buy empty fire alarm sheet metal cabinets in 14" by 14", 14" by 18" and 18" by 24" sizes. I get them from an alarm wholesaler. They cost around $25 each, and I can mount a few 66M blocks and/or 12-port data panels (the ones that use the same footprint as a 66M block) inside them. This makes a neat enclosure when the wiring is exposed in an open area such as a basement in a home or small office closet.

Obviously, every run is a homerun, and every connection is a cross-connection. I terminate the 4-pairs on both sides of the 66M50 blocks, and the KSU blocks, also 66M50's, are wired only on one half, with bridging clips feeding the cross-connections.

I always take the incoming CO feeds and make a multiple block, with 4, 5, or 6 appearances of each CO line, using the loop-through punch-down method. This allows a connection, via bridging clips and cross-connections, to the KSU, and ancillary stuff like alarms, fax machines, answering machines, external bells, etc.

When I see a Leviton or equivalent "whole house" wiring cabinet, I rip out the 110 hardware and put in 66 blocks. Try troubleshooting in one of them, looking for a swinging S/C. It's impossible to do without removing every wire, and then when you go to reterminate them, guess what? They're all an inch shorter. Try that a few times, and you's see why I love (to remove) Leviton. They are helping me make my second million $.

I am encouraged by the wealth of knowlege and experience on this forum. Until I found it, I thought I was operating in a vacuum, and despaired to find other like-minded techs who are encountering the same BS that I do every day.
Posted By: Anonymous Re: Best Backboard Wiring Practices and Standards? - 07/18/07 09:49 PM
I like this for residential panels;

[Linked Image from dynacomcorp.com]

Looks fancy on the outside, but once it's open its a familiar sight. smile
Actually, the concern should be to make the installation uniform and consistent. Going into every job with a different-sized piece of plywood, painted in a myriad of colors isn't consistent. I laugh when I encounter plywood backboards that are stained! We are talking about a phone system, not a piece of furniture!

Every system has input and output and output connections that can be terminated upon 66 or 110 blocks, so no block layout is "system specific". If your system only has three tails, then simply leave the fourth space vacant for a future tail. Space really should be left on the backboard in the form of vacant brackets to accommodate every possible tail that the cabinet can have.

Bill, I am with you. I've stopped purchasing green or yellow backboards. I am still sitting on some red ones, but once they are gone, that's it. I have found that blue (station) and purple (PBX) are most appropriate.

Kumba: I never let columns of blocks go beyond four high. Jumpers get to be too "wobbly" and easy for the cleaning people to snag with the vacuum cleaner handle. Using factory backboards really encourages stack multiples of two or four blocks maximum. Odd numbers are never appropriate.

Actually, there should be two mushrooms at the top of each column of 66M1 blocks, aligned about an inch above each side. This prevents the same mushroom from having jumpers coming in from different directions and becoming entangled. Here's an example:

[Linked Image from i98.photobucket.com]

Please note that this is my "lab-or-atory" at home, so it's not as tidy as it should be.

Believe me, the Bell System spent a fortune in designing this modular backboard system and for good reason. Using these, I can mount eight 89B brackets, perfectly-aligned, with four screws in about a minute. Not only that, once I place one backboard that's level and plumb, all subsequent backboards are butted together and end up the same.

Now, at a typical technician's wages, I have to ask the question: Is it cheaper to not use backboards and pay a technician for an hour of time lining up a dozen blocks consistently or to spend an extra $25.00 on the job and have the blocks laid out in 15 minutes, consistently every time? Sounds like a no-brainer to me.

Look, I understand that anyone here who knows me also knows that I am a neatness pr&%k, so perhaps I am going a bit too far. Hey, Jeff knew what he was in for when he posted on this topic!
Your assertion comparing costs for labor vs store-bought parts is absolutely correct. I often cite that argument when advising people to buy data patch cords at $1.00 each versus trying to get all those itty bitty wires into the 8p8c plugs, at $90 per hour.

On large jobs, I compromise, and take a 4-foot carpenter's level and pencil in a series of horizontal lines, every foot or so, and vertical lines, each the width of the level. These become the lines where the type-89 bracket feet will be screwed.

On small jobs, I just measure a few points and start screwing. (In a nice way.)

It drives me crazy to see anything that isn't level and plum, and I don't let my work get that way.
Or option 3 where you grab the Ryobi vacuum laser level and use 89D brackets.....

Carl
Nah, I use the tried & true method: A clear tube with water in it. On Fridays, we use Vodka.
Original post revised to include picture.
Ed, I know....Don't be too mad at me. The piece of plywood was already there smile
Standards, neatness, and as much possible protection from mop handles, buffers, spare ladders, etc. I knew a commercial installer whom only installed jail phone systems. His work was so clean and consistent that many vendors, tech support folks, PMs, QC folks, etc, could immediately notice by name whom performed the install. Nice home lab!
Actually, the concern should be to make the installation uniform and consistent.

I have to get some pictures. With nearly every new system we do I assemble the backboard in the shop. Since we normally do Partner systems a 2'x4' backboard is sufficient. It gets painted with two coats of silver gray enamel. (The customer can have any color as long as it's silver gray.)

The KSU always goes on the left with the 66 blocks for the cross connect going right from the right side of the KSU. They are in order also from left to right: KSU extensions, KSU CO lines, premises wiring, CO lines, Krone block RJ-21x with secondary protectors below. I like to use half "D" rings above the blocks.

For layout I use our "standard template" that gets taped to the board. All screw holes are pilot drilled, the template removed and the KSU, blocks with 89 brackets and half "D" rings mounted. I never use drywall screws! VERY tacky!

After everything is in place I install our premade breakout cables (25 pr for the extensions and 6 pair for the KSU CO lines) using mounting blocks and telephone gray ty-raps from the KSU and punch them down on their respective blocks. The CO block will get a piece of 25 pair down to the protectors then from there a connectorized cable for the RJ-21x.

When it's all done I take it to the customer, slap it on the wall and punch down the premises wiring and install the RJ-21x. (I remove the KSU or carrier before transporting.) All I have to do then is plug it in and connect a ground wire from the protectors and cross connect the extensions and CO lines.

Needless to say EVERY system we do, with minor variations looks exactly the same.

-Hal
Quote
Originally posted by Kumba:
Bill: Thanks for the info. I have never used the color codes before. Most of my installs are only 1 or 2 66 Blocks for stations and 1 66 block for CO lines.
They come in quarter field which is with just two 89 type brackets, if you get the wood ones you could saw those in half if you wanted. It really does make for a neat install as you can see by Ed's photo.
And if you use BIX you could save 75% of the block space.....sorry just had to say it.....

As KLD says....the BIX made me say it.

Dave
its ok mooretel, im a bix lover too, work great on data too
Didn't they make a lighter? Maybe it was pens. :rolleyes:
Just goes to show you how versitile they are !

Dave
Quote
Originally posted by justbill:
Didn't they make a lighter? Maybe it was pens. :rolleyes:
I thought it was disposable razors.
All that year 'round snow and ice must explain the BIX thing, it's too cold for the grey matter to work.....no one this side of the Big Water seems to even know what they are except to level Partner covers that the paging amp is sitting on that has the MOH radio sitting on which has the wireless router sitting on...... Oops, wrong thread..... wink
If you don't have room to put in 66 blocks, you shouldn't be mounting a system there. smile
CT, help :toothy:

In a way Coral Tech is correct. With an appropriate area for the backboard, KSU, et al, whether it is BIX or 66 or twist-and-solder really makes no difference.

topic
To my friends in the Tampa Bay area, and that includes "Sarasota" Skip, becareful useing just any old paint. Most jobs call for a Fire Proof paint and that stuff isn't cheap. Not sure about the other parts of the country. You can buy the premixed gallons, or do like I did buy a 5 Gal and had the power mixed in. So like Hal you can have any color as long as it is off white. smile
I just "borrow" a gallon from the painters.
It's not "borrowing". I have a contractor that says if the material doesn't leave the site it's not stealing, so feel free to use anything you want for your project.

The Italian electricians used a phrase to describe him that I can't repeat here.


Carl
The only comment I have is, GET THERE BEFORE THE LEC! I swear they snap chalk lines corner to corner and install the terminal smack at the intersection, completely hosing any hope of a neat install. All those that haven't moved the LEC's terminal/can, raise your hand! That'll be easier to count! On the fingers of 1 finger! smile John C. (Not Garand)
The older LEC techs don't even need the chalk lines any more, they can do it in their sleep.
Most jobs call for a Fire Proof paint

I've only had one idiot architect that I can remember spec that for the telephone back board. It isn't an NEC requirement and I know of no local code here that requires it either. I just painted it with our standard silver gray and nobody knew the difference.

I do remember fire resistant paint being common many, many years ago on electrical backboards. I wouldn't even know where to get it today.

-Hal
heres powder that can be added to cheap interior paint for fire retardant $10 pack plus $5 a gal for oops paint 15 a gal to be fire retardant.

Quote
Works in inexpensive, low grade Interior Flat Latex Paint only!!
I asked a GTE engineer years ago about the requirement on a project we where doing and he said "don't worry about it " so I never have
FR paint or plywood is not something that is enforced by the NEC, it's a building code issue. I believe that BOCA and ANSI standards do require fire-retardant paint or plywood. This is definitely enforced around here as recently as last Thursday on an inspection of a job we did.
Here in schools it's mandated to provide fire retardant plywood for backboards. Any painted backboard must leave all fire retardant stamps unpainted so you end up with a patch work looking backboard.
guys you know what encker is that real usefull you dont need a plywood with tose
Quote
Originally posted by Aircom KC:
I like this for residential panels;

[Linked Image from dynacomcorp.com]

Looks fancy on the outside, but once it's open its a familiar sight. smile
were do you get them?
Might I also add that I don't suscribe to "over-labling". I always try to consider the next tech coming in behind me so he won't have to try & figure out which tails are the CO lines, PRI, T-1, Digital & Analog ports.

When it comes to external paging, we always use Valcom & I always insist on 1 cable home run for every speaker/horn terminated on their own 66 blocks, down one side only, with the audio & -24V looped down the other side & bridge to my cables. So when it comes to trouble-shooting, I can just pull all the clips & get down to it.

:thumb:
IPKII -

Home runs are always better. They're not real practical on large PA jobs, but the more, the merrier. (I just finished an 8,000+ speaker job at JFK airport and all those home runs just wouldn't have worked)

One thing though. My practices have always been to NEVER run solid wire for a speaker. With the vibration associated with a speaker or horn I was always taught to go with stranded wire to prevent the solid wire from eventually breaking off.

I like the idea of pulling the bridge clips to test - very handy! And if you're running audio and -24 I imagine then you're using powered speakers. When I last priced them out (admittedly a long time ago) they weren't cost effective against a constant voltage system with a centralized amplifier(s) once you got past 10-12 speakers - is that still the case?

Sam
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