I am so bad about long posts and I know it, but I have to do this after what happened today.

By now, you all probably know that I am a real stickler about doing outside cabling correctly. Much of it is kind of a no-brainer, but the protector is the most important part of the equation.

There are lots of manufacturers that make 66 or 110 block "protectors". They are less-expensive, involve little knowledge other than color code, and they are generally easy to install.

Typically, they involve a split block, where the input pairs are on the left side and the output pairs are on the right side. Makes perfect sense, but they aren't TRUE protection. Here are a few issues:

1. Many "icky-pic" cable compounds are flammable and therefore their terminations must be either outdoors or contained within a fire-retardant splice case. In the latter, the "icky-pic" is spliced to an air-core cable feeding into the protector. To simply punch down "icky-pick" cable on a block indoors is in a word dangerous. If something goes wrong and there is heat, spark or flame, the block could catch fire. Not to mention that once "icky-pic" is on a block, it's there forever. It will be a mess, no matter how good of a job you do cleaning it.

2. Simple "punch-down" 66 block protectors do not provide nearly the protection levels that are required in the real world. Think about it; you have a split block where the input cable comes in, goes through the protectors, then leaves on the right side. On a typical split block, the clips are less than 1/4" apart. 1/4" separation during a lightning surge? Since lightning takes the path of least resistance, why would it choose to go up, through protector modules, then back down to the output side of the block? Of course it's not going to do that. It's going to jump across to the adjacent pins on the block. Kind of common sense when you think about it.

3. Let's face it: Most interconnect companies are not equipped properly to install and support outside plant installations. If a protector module fails on one of these blocks, will they have replacements on the truck? NO. Will they go to the supply house and buy a replacement module? NO. Will the local supply house (if there is one) have them on the shelf for purchase? Probably not.

What will happen? The technician will bridge the input and output pairs across the block. If it's a block that doesn't permit this by using bridge clips, they will pull and splice the pairs to restore service.

NOW, here's what "real" protectors are and why:

1. There's always a chance that an aerial or underground cable can be crossed with high-voltage power. This usually happens when someone digs without having cables located. Basic protectors are designed to protect against surges or lightning, something that occurs within a fraction of a second. Anything more than that and the basic protector doesn't do much of anything except burst into flames or blow apart.

2. "REAL" protectors include an intentional "weak link" to protect against maintained faults (contact with high voltage).

Imagine that I am using a backhoe to trench a pipe line. In one dig, I cut through a 7,200 volt power line and a telephone cable at the same time with my bucket. I see sparks and immediately shut down the machine. Even if I am 100% alert and able to react, it still took me 10 seconds (at best) to remove the bucket causing the cables to be crossed. In that ten seconds, the telephone cable, possibly all pairs, were energized at 7,200 volts.

Protector modules shunt excessive voltage to ground, they aren't designed to do this for more than a few seconds. That's were the design of the protector (building entrance terminal "BET" or protected entrance termial "PET") comes into play.

Real BET/PET's include a typical 26 gauge stub cable that intentionally reduces the size of the underound cable pairs. This must be at least two feet in length to have any effect. BET/PET's with stub cable entries have a mark on the jacket warning that the cable not be cut shorter that two feet. The "real" protectors that have punch-down or spliced input connections have this two feet of smaller-gauge wire built inside the unit.

True, if a maintained fault as mentioned here happens, the reduced-guage pair(s) will burn out and the entire protector will require replacement. Still, at least the building didn't burn down. The pair(s) simply burn "open".

3. Plug-in protector modules, regardless of the type, are only as good as the mounting assembly itself. Lightning and power crosses don't follow any rules or wiring diagrams. They get to ground as quickly as possible.

In summary:

Cheaper protectors are like buying used cars. They won't do the job as well as a new one might. Expect the customer to pay about $600.00 per 25 pair terminal for it to be done correctly. Remember that you have to provide the protected entrance terminal PLUS the plug-in modules, since the modules usually aren't included with the termial.

A #6 AWG grounding conductor must always be used for any protector over 25 pairs. In general, up to two pairs can be grounded with a #12, and up to six pairs can be grounded with a #10. Imagine twisting all of the individual stripped wires together; their combined total diameter should match or be smaller than the ground conductor.

There are a lot of items in our industry designed to make our job easier. With protection, if it's really easy, it is not right. If you don't truly understand this part of the industry, you are risking liability as a contractor. When in doubt, sub out the work to an outside plant contractor, they will work with you. If there are none listed in the local phone book, ask any electric, telephone or cable TV employee you see on the side of the road. Just about all utility companies use sub-contractors who don't need to advertise. They know how to do it correctly.

In closing, don't risk having a cheapo "protected" 66 block being blown off the wall. Do it right or don't do it at all.
We restored service to a site (at a state prison) recently where this occurred due to our competition (the low bidder) beating us out on a buried cable installation.

Glad to collect the money for the repair/replacement, but we lost the original installation job due to price. We were doing it right and what we replaced was done wrong.

Things that make you say HMMMMMMMMM.





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Ed
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How come there's always enough time to go back and fix it a second time?

Yup, that's the way we do it. We use Reltec (or whoever they are now, Emerson?) BEPs and 5 pin protectors. Not cheap but like you said the only way to go.

Amazing how many times we see cable run between buildings with improper cable and improper or no protection. Many times we are there because lightning wipes out whatever is connected to it.

We did OSP for cable many years ago. Telecom is different but once you are used to the OSP regimen learning to work with copper instead of coax is not that difficult.

Most times when we were doing underground it was in a common trench with telco and we were there at the same time as the telco splicers. Always pays to look over your shoulder to see what the other guy is doing and ask questions.

-Hal

Ed In that state prison, did they ground the protector to a "Chair" in a back room?

Im sorry to bring back such a dated post, but it is important and relevant to many contractors performing outside cabling. Nonetheless, since I am a newbie, I would like to know what the correct term is for the allpath cable gunk. I'm assuming that is what you meant but is it really icky-pic? In California, I would see these kinds of installations frequently with no protection whatsoever. If I understand it right, are you saying that an outdoor cable with icky-pic should not be directly punched down to a 66-block because the gunk can be ignited by a short? Now that I've got myself thinking, I short pairs on 66-blocks with my snips all the time to test the pair. Should I stop?

"Allpath" is one of the biggest misnomers out there. If you hear someone using that term, run in the opposite direction. It is "ALPETH", as in Aluminum Shielded, Polyethelene jacket. There's also CUPETH and STALPETH. "Allpath or Outpath" has never been proper terminology and has nothing to do with protection. It's just a bad "I think I know what I am talking about" term.

No, icky-pic cable should never be punched down indoors whatsoever. There are certain exceptions, specifically situations were a BET/PET has a self-contained splice chamber where the flamable filling compound and the cable's terminations are sealed in a fire-retardant area. To simply punch a filled cable onto a block has never been safe or legal. When I refer to "icky-pic", I refer to any cable that contains a gel filling compound. These cables are rated for outdoor use only. There is still also the appropriate sheath bonding measures, etc. that must be followed. There is a lot more involved with outdoor cabling than simply buying filled cable and a punch-down protected block.

I know what you have mentioned about installations in the Southwest, particularly at resort hotels that involve multiple buildings. I have seen how filled cable is simply punched down on a 66 block in an electrical enclosure on the outside of a block of hotel rooms. People think that this is proper.

If this was so "proper", why do telcos spend ten-times the material cost to terminate these cables proplerly? There is so much more to installing outdoor cabling than what appears to be obvious. This is a completely different industry and interconnects need to leave these installations to the professionals.

Most telcos bring these cables into the building for a minimal distance and then splice them to cable stubs that are not filled. These splices are accomplished using bolted aluminum, steel or Fiberglass splice closures that will effectively contain potential fires in the event of maintained cable contact with high voltages.

A filled cable may be terminated outdoors without fear of fire danger. While still not appropriate, this type of cable can be terminated just about any way desired as long as its terminations are outside. This practice is very common with regular residential network interfaces; gooey cable pairs are terminated, BUT, this occurs in the "telco only" compartment.

Shorting pairs with snips on a 66 block are not a problem. The sparks that cause fires are the ones due to burning cable pairs due to maintained exposure to high voltages. Many gel filling compounds in direct burial cable are petroleum-based and will react to heat, not simple sparks. A properly-installed and terminated filled cable won't ever end up anywhere near a pair of snips on a block. That's the trick; finding out if it's properly installed. If you get icky-pick on your tools or fingers, it's not properly installed.

Thank you for the clarification. I just assumed the cable would be spelled 'all-path' because I see it being installed outdoors in an 'all-types' scenario. I rarely pull cable nowadays and have only been in contact with ALPETH on a 'pick-this-up' basis. I have never had to spell it for anyone. Regardless, ALPETH it is.

There are lots of ex-telco people here who have decades of experience on this area of the trade. You'll never have a problem getting answers and support on this subject here. Me, I am not ex-telco, just very opinionated if you hadn't already noticed.

Maybe not ex-Telco, but very knowledgeable on outside plant among many other things. :bow: Ed the first post in this topic would be good for the FAQ's, if you wouldn't mind.

Ed, I would like to know what kind of BET you consider to be high quality. It sounds like prefer stub in/out spliced with MS2 or Scotchlocks. What about protectors with stub in/110 out or stub in/66 out?

Thanks

Units made by 3M, Circa, Corning or Emerson Network Power are very good utility-grade terminals. Stubbed units really aren't the norm anymore since many manufacturers incorporate two foot fusible link stub within the terminal. In doing so, a stub isn't necessary. I prefer that the incoming cable be spliced (I use 710 modules). This way, it's difficult for inexperienced people to bypass the protection. For output, I prefer 66 since it doesn't get as congested as 110 or Bix outputs when there are lots of tags and jumpers. Hope that helps.

Porta makes some good ones also.

does anyone know of a good outside plant cable contractor in the Miami, FL area. i need a 300 pair about 650 feet with protectors installed. thanks

Mike:

I might suggest contacting your local Graybar branch and inquire about anyone who might purchase this type of cable on a regular basis. You might also try contacting Clifford of Vermont (800-451-4381) to see if they have any buyers from your area.

Lastly, we have a "find and installer" category here that might give your request some better exposure.

Protection at subs premises has been practically non-existent here for a good many years. Both the original BT master jack (introduced in the early 1980s) and the current NTE5 network interface incorporate a spark gap tip-to-ring, but that's it -- No series components, nothing to ground.

Here's a copy of an old Post Office training booklet which shows how it used to be done:

Protective devices used in telephone & telegraph lines (PDF, approx. 1.3MB)

Have to ask, Paul. Have building fires increased due to non-protected terminals, or would the 'powers that be' even admit to such a fact? (Just because you are paranoid does not mean someone is not watching your activities!) John C. (Not Garand)

I have installed hundreds of single and multi-line service drops. I totally agree with the following premises:

- Electricity and Lightning follow the path of least resistance to ground. Electricity and Lightning will follow the greatest “potential” to ground.
- Outside plant should be bonded and grounded to the multi ground neutral (MGN).

I have a couple of questions:

1. Why are the non-splice blocks such an issue? The gas carbons will engage when electricity or lightning are detected. With the carbon engaged, the flow of electricity will be directed to the #6 ground. Even if there are a sizable number of cable pairs on the other side of the block, the carbon will shunt the electricity to the ground. The electrical path will want to flow to ground, not the user side of the cable. There won’t be enough concentrated potential to warrant the electricity to flow to the user side. Even with a splice terminal, if there are multiple 100 pair terminals they will only be grounded with a single #6 ground that is common to all terminals. I believe it’s because a #6 ground properly grounded provides sufficient potential to direct lightning/electricity.
When using single pair and six pair drops to the home or business, the drop and the inside wires are connected to the same lugs on the protector. The inside wire is not at risk because when the protector engages it creates a path of least resistance for electricity to flow to ground. I wouldn’t expect that the electricity or lightning would “jump the pins” on a direct 66 block terminal because the gas carbons will engage and direct the electricity to the ground wire with more potential and not the inside wire.

2. Buried Service and icky pic: I said to myself that can’t be true. Icky pic can’t be flammable. I scrapped some off the buried service wire and lit it with a match and it did burn. You’re correct! Then I wiped an icky pic’d drop wire, cleaned it and tried lighting the wire. It burned. Then I grabbed some two pair aerial drop wire–(non icky pic wire) and lit it with a match and it burned! Then I grabbed some 6 pair aerial plant wire and lit it with a match and it burned. Then I grabbed some OSP #22 gauge and lit it with a match and it burned. I would not call the icky pic an accelerant. Icky Pic burned very similar to the PVC wire. I tried lighting an 12 pair buried service outside jacket and it did not burn with a match.
My reason for doing this experiment was that I have installed many 6 pair buried service drops with icky pic. I would think that cleaning icky pic on a block is “good housekeeping” and important for that reason. It is messy. Also, individual service wires are never enclosed in a splice. The individual 6 pair buried service pairs are connected to the protectors themselves. So are 2 pair drops. So are 6 pair aerial drops. There are no splices. Of course with buried service, the metallic sheath of the cable is bonded and grounded (at both ends) and the protectors are grounded. Aren’t proper bonding and grounding the keys here? There is no fire-resistant splice in any these applications. So, why wouldn’t this apply, as well, to the non splice protection terminals? Aren’t the protection carbons and the bonding and grounding more important than the splice?

doctor. How about dropping by the "Phone Booth" and you'll find a thread for new members....introduce yourself.

Enjoy the BB, keep your sense of humor, and have some fun.

EV607797
Ed

I really enjoyed your post. I read every word. I have really enjoyed my short time here with you guys. I was just about to the point of wondering if anyone out there cared anymore about quality in their workmanship.

I started here as a helper to an old retired guys from AT&T. He was a new guy to the business then (only been doing it 35 years) and then came here to help out. I, needless to say wasn't taught shortcuts or should I say how to halfass something. It was this way and thats how you do it period. He was right.

I am having to show contractors that come in here on new buildings how to lay it out right. Most know me and that I am not hard to get a long with if you do it right. But if they come in with the intentions of doing a poor job and taking the money and run. Not good for them.

I am like you guys in the respect i do what i do and take it very seriously. I don't take shortcuts and do my best to do what we do right the first time. I teach my guys the same way I was.

Well said, Mike! :thumb: :thumb:

Even though electrical protection is being discussed, all the end customer really wants and needs is simply quality, reliable service. It's our responsibility to maintain the correct standards and practices. Just my opinion, but it's normally when folks get in a rush, that they decide to cut corners, take shortcuts, etc, usually ending up causing numerous safety hazzards, poor service, etc.

The gas carbons will engage when electricity or lightning are detected. With the carbon engaged, the flow of electricity will be directed to the #6 ground. Even if there are a sizable number of cable pairs on the other side of the block, the carbon will shunt the electricity to the ground.

You are forgetting one thing. When there is current involved such as from lightning or a power cross something has to give. This is why BEPs utilize 26 ga wire in their stubs as fuseable links. Its also why there are sneak current coils or fuses in protectors.

Spark gaps, carbons, gas tubes or MOVs are like a "crowbar" that will short the pair together and to ground when the voltage reaches a certain level. If the current caused by shunting the voltage to ground is large enough any fuses or fuseable links will open. Many times the current is so large that the protector will be destroyed also. (I've seen 5 pin protector covers blown across a room.) Once the protector is gone you now have an open circuit. If the voltage is still sustained (power cross or lightning) on the OSP side there is an arc potential between any exposed point such as a block clip and the other clip or ground. Insulation breakdown voltage factors into this also. This is how fires start.

-Hal

Thanks Hal. I appreciate your feedback. I reviewed the specs on few of the direct block protectors. This included a couple from Porta Systems. They indicated that the 26 gauge fuseable link is built into the BEP direct block. Does this offer the protection that is needed for a fuseable link? Won't the pairs "burn open" in this case?

Won't the pairs "burn open" in this case?

Yup, that's exactly what they are supposed to do. When that happens that pair on the BEP block can no longer be used. If enough of them burn open and the loss of capacity becomes a problem you replace the BEP housing or block.

-Hal

Sorry, looks like I missed that question before.

To be honest, I've not seen any statistics one way or the other on this. A much larger proportion of telephone wiring is underground now compared to the past, although we still have a lot of overhead in rural areas.

Britain tends to have much less severe and much less frequent thunderstorms than many parts of the United States as well, so in today's cost-cutting climate lightning protection has taken rather more of a back seat.

Also, while contact with HV power is possible in some places, our cabling arrangements tend to keep telephone well away from it. You'll find phone running below 240/415 or 240/480V local distribution cables, but never on the same poles with high voltage. When phone has to cross HV at an angle, it almost always dives underground for that short distance then comes back to poles on the other side.

That fusible link is what saves the building. Despite the fact that a maintained cross with power will effectively destroy the BET, it does it's job by having pairs that blow "open" to stop the direct metallic connection between the fault and the building.

Since the fusible link is either contained within the UL listed BET itself, or within the confines of a fire-retardant cable stub, what fails is a cable pair and any flame or spark is contained effectively.

Again, the fusible link is the proverbial (and intentional) weak link. It's understood that when it fails, the BET is shot. Lose a $1,000.00 BET, yet save a $1 million building, not to mention the potential personal injury or loss of life from a resulting fire. Remember, this cross with power can happen miles down the road, not just at the immediate premise.

Good practice is to splice in some riser tails into a splice closure mounted inside the building, then take that to your protectors, or you can get the protectors with the tails already terminated and do the same thing. I think the point of protection has been a little skewed, its not about fire protection, it is about electrical protection for your switches, routers, modem equipment, and last and not least the end user's safety. I have never heard of a building catching fire because pic flashed and burned. I have however seen first hand what happened to a lady in Texas whose protector was not installed properly (Not grounded) by the telco installer, the scenario was she was chatting to a neighbor in a storm...the rest i leave to your imagination!

I did see that 1a2 key caused a fire in a Macdonald's. This was years ago and I didn't install it.

But my best guess is that a fuse was strapped on a lamp lead.

A good one and true story is about the telco guy who grounded the protector to a steal fence.

The owner would chain the dog to the fence and every time the phone rang the dog would bark. Go figure this one out.