One special requirement when prepping OPGW ends into a Stainless Steel 28″ Coyote closure, or any COYOTE® splice case for OPGW, is to add a Green Sealant Kit (Cat. No. 8003411) to the cable before wrapping the tape.

This procedure ensures that the closure is air tight. Without using the green sealant kit air and more importantly water can travel freely through the OPGW strands.

Once water enters a closure the “life” expectancy of that location will be reduced below the 50 years it’s expected to preform. From the operators perspective it’s highly unacceptable to have any location be susceptible to future failures, especially failures that could have been prevented by doing it right in the beginning.

The photo collection below depicts how the green sealant kit should be installed.

First, unwrap the OPGW strands and find the middle strand. Once you identify the middle strand wrap the sealant around the strand as show in the picture above.

Then re-wrap the strands while continually weaving the sealant into the strands through out the entire process. It is important to note that bending the strands at anytime during this process is not advisable. Any bends will take away the natural form that the steel and aluminum wraps have and make it nearly impossible to re-wrap the cable.

You should end up with something similar to the picture above. The sealant should be evenly spread across all strands and is not bulky. If the sealant is bulky (too much) the cable will not fit into the cable port of the closure after the LOCK-TAPE Sealant System has been added.

OPGW Splicing: Adding Sealant to Cable Ends is a post from: OLC Fiber Splicing of Denver

There are many, many man hours involved in testing and proofing fiber networks. Thus, it is important that time is well utilized and the data is collected properly. Although most OTDR’s manufactured today are very easy to use they don’t do the job for you. They are a tool to aid you in doing your job.

We were recently sent a pack of traces for review for one of our customers. There was an anomaly in the 1550nm window data that they could not explain and the contractor that did the work didn’t have any answer for them either. The contractor actually said the fiber was bad.

The anomaly (shown in the photo to the left) was caused due to the fact the OTDR being setup wrong by the technician. This particular OTDR has a macro event setting. It was turned on and for some strange reason the trace data had a false event imposed into the data.  In all actuality there are no events at these points and the fiber cable was not damaged.

Tips when using an OTDR:

First, always use a launch cable.  An OTDR pulses must traverse a minimum distance before the OTDR can take meaningful measurements. Always start with the OTDR set for the shortest pulse width for best resolution and a range at least 2 times the length of the cable you are testing. For fiber cable lengths of 18,ooo feet or less it is best to use a 500ns pulse width. Make an initial trace and see how you need to change the parameters to get better results.

At this point if things don’t look right re-check your settings, make sure all connectors are good and use your eyes to verify that the trace data you are collecting is clean of any anommilaies.

A well trained technician knows that the OTDR is just a machine and the results it gives you are based on what you do when your collecting the trace data. If you’re un-trained or are not familiar  with the problems that can arise when using an OTDR, the time you spend testing is all for not. If the data isn’t collected properly then the tech will be returning to the job to get the right information.

Fiber Optic Testing – Anomalies is a post from: OLC Fiber Splicing of Denver

The following photos shows a splice tray from an OPGW 24 fiber splice location mounted inside a Windsor splice closure.

The first pictures shows that the tech used connector boots and silicon to protect the fibers from the edge of the steel tube. It didn’t work.

This next one shows why there was high loss fibers in the tray. Poorly routed fibers caused macro bends and resulted in a few broken fibers as well.

The customer was turning up a 10 gig connection and had high loss fibers across 3 splice locations. All locations had to be re-done.

Fiber Splicing Resulting in High Splice Loss is a post from: OLC Fiber Splicing of Denver

You could be at a Power Plant, Substation , Switchyard or on a transmission line. That is why it is extremely important to recognize the possible shock hazard situation for each of the different places you may find yourself in.

As should be no surprise here, there is only one requirement for a electric shock hazard and that is electrical energy. Sources of electrical energy at a work site could be in the form of electro-static charge, elctro-matic induction, accidental energization, lighting or induced voltages and current from a parallel line.

The phrase ‘personal protective grounding’ used here should be understood to mean;  you taking action to secure your safety regardless of what someone else has told you. The number one rule that my fellow workers and I live by is this; If It’s NOT Grounded. It’s NOT Dead! If you follow this one  rule you will be around a very long time. OPGW can easily be at a different potential than the soil at the work site. Your job site is only as safe as YOU make it.

A few electric shock hazards associated with splicing OPGW are;

• Electro-static charges
• Electro-magnetic induction

Balanced phase currents result in little induced voltage
Unbalanced fault currents produce high induced voltage
Significant ground fault current flows in the static wires
Energized power line is parallel to de-energized static wire
Ground fault currents are injected into the soil thought the tower footings

Significant Transfer Touch Hazards may exist here.

There are several things needed to create a Equal Potential Zone and each situation is different. There may be different requirements then the one’s that I will list out below. Be sure to follow ALL guidelines and recommendations set forth by the operator.

Typical Tools Used for Grounding OPGW

• Removable hot-stick
• Type 1 C-Clamps
• Protective Ground Cable – Type 1, Specifications B 172, Class K or M
• Conductive Mat

Typical OPGW Work Sites

• Wooden Transmission Structure
• Steal Transmission Structure
• Substation

Grounding a Wood Structure

When your at a wooden structure on a transmission line, after you have identified the electric shock hazard, you then establish a low-resistance work site ground. You do this by driving a temporary ground rod and bond the pole to ground. The ground road should be at least ten feet from the pole.

To establish an equal potential work zone you first bond the splice vehicle to the work ground, then install the conductive mat between the splice vehicle and the wood pole. Then bond the conductive mat to either the wooden pole or the vehicle, but not both.

The next step is to include the OPGW into the equal potential zone. First, install temporary ground cable between the work site ground and the OPGW above the  storage assembly. Then install a temporary ground cable between the OPGW tails above the storage assembly or splice case.

All grounds are to be placed and removed using a removable hot-stick.

Once you have completed the Equal Potential Zone you may now proceed to touch the Optical Ground Wire

Don’t ever let your guard down.

Be safe

Splicing OPGW – Personal Protective Grounding is a post from: OLC Fiber Splicing of Denver

This question crops up from time to time, from both project supervision level personnel to the hands on techs in the field.

When using the word ‘calibration’ with regards to arc fusion splicers there are really two meanings.

The first meaning factory calibration and the second, arc calibration. Just for the record we are talking about factory calibration in this article.

A field supervisor/engineer asks; Are your splicers factory calibrated?

The answer is no . There is no way to “factory calibrate” a fusion splicer. The looks on their faces are priceless. The answer they are excepted would be, “Yes they are.”

A technician asks;  Should I send my  machines in for re-calibratation? I heard all they do is clean them. I can do that myself.

The answer is yes. Send that machine in every couple of year and have if looked over by the professionals.

Confused yet?

Well don’t be. Both answers are correct. Let me explain.

Although the term ‘calibration’ is used when describing the accuracy and reliable of a fusion splicer, there is no way to calibrate a splicer. At least not in the sense when thinking of measuring instruments like an OTDR or power meters. Both of these are devices that can and should be calibrated at a minimum of once per year.

Rather in the case of the fusion splicer, it is recommended to have periodic service and routine maintenance preformed to maintain optimum performance.

Although you’re not sending it in for calibration per say the machine has several movable parts that can and do wear out which takes the splicer out of tolerances that prevent it from preforming it’s job properly.

The most common parts that wear out on a splicer include, but or not limited to;

• Electrodes
• V-Grooves
• Fiber Clamp Chips
• Objective lenses
• Motors

A fusion splicer that is a real work horse will, over time, develop  major tolerance problems that can greatly affect it’s performance. The two biggest culprits, V-grooves and fiber clamps chips. These two items wear out which effects fiber-stuffing distance which in turn affects the splice integrity and loss.

Fiber-stuffing distance you say?

When the main fuse method is initiated the fiber are brought together and additional end pressure is applied. The additional end pressure allows the fibers to move towards each other slightly as they melt. How far they move, called overfeed, auto-feed or fiber-stuffing is critical. Too much or too little and the splice will not be satisfactory.

As the surface of the V-grooves wears down and the clamp chips naturally become loose due to repeated use the fiber will then begin to slip in the fiber clamp chips which will change the  fiber-stuffing distance. A tech cannot see this ‘slip’ as it is not detectable with the naked eye as it happens.

The way a fiber technician detects it is in the splicers monitor. This is usually in the form of a splicing disaster called a ‘waisting’ or ‘necking’ splice. But it doesn’t always show up just as a splice with visible imperfections. Many times the problem is deeper into the matrix of the splice. At the level of core and clad offsets. No matter how you look at it, the result is the dreaded re-burn. Arg!

Another critical part that wears out on a fusion splicer is the objective lenses. If your a tech that takes care of your machine then you know that the cameras are crucial to fiber alignment in a Profile Alignment System (PAS).

Over time the surface of the objective lens may become scratched or pitted due to access slag from thousands of electrode discharge  (a slightly white/gray film that builds up on the inner sides of the V-grooves and lens surfaces).

In some cases the seal that keeps dust and particles from getting inside the lens can dry out and crack. Once this happens all it takes is one particle to get underneath the lens and in most cases the splicer will no longer be-able to function.

So, if you’re of the thinking that all the factory does is clean up the machine and calls it ‘calibration service’. Think again. There are several things that can go wrong in the course of work day. Any one of which mention here can affect the performance and reliability of the fiber.

Periodic maintenance on your fusion splicers will insure that your splicing is 100% reliable – no question – no re-burns.

Keep-it clean grasshopper!

Calibrating Arc Fusion Splicers is a post from: OLC Fiber Splicing of Denver

This first one is a classic. I’ve been in the business a long time and I can say that this is the first time I’ve ever seen this. The tech defiantly had no clue how to prep and wrap the cable entrys on a Coyote closure.

These next two come as a surprise. (Not really)

“That one you go to next should be pretty easy. It’s only a Tyco A with six splices in it. One of our in-house tech’s did it about a year ago.”

If your fiber tech’s are doing this kind of work you might consider re-training them.

Unacceptable Fiber Optics: Are You Doing This? is a post from: OLC Fiber Splicing of Denver

IMHO the CMA is the best OTDR every developed for testing fiber optic networks. The rugged exterior and the reliability of the equipment has yet to be match with todays OTDR in production. The draw back to all machines of that era was how the traces were transferred to a desktop computer.

Choices were limited to a floppy drive or a par net setup. The shear number of trace data from a large network such as a FTTH project can take hours to transfer using a floppy. 1.44 meg isn’t that many files when your scan times are long and your acquiring multiple windows. If you own one you know what I’m talking about.

Well, those days are over. The compact flash upgrade brings an old machine back into the game. File transfer headaches are a thing of the past.

Here’s what you get when you upgrade ole Betsy;

Compact Flash (replaces internal hard drive and floppy drive)
USB Card reader/cord
2GB Scandisk

There is only one thing you will need to train yourself  NOT to do, and that is do not remove the flash disk while the OTDR is on. The card is not hot swappable! There is a big warning label on the inside of the floppy door lid reminding not to remove the card. Be very careful as old habits are sometimes hard to break.

One last note. We have had several people contacting us over the past few months about upgrading their OTDR’s. We are not the place to call about repairs. We are simply a fiber splicing and testing firm like many of you. If you want the upgrade please contact Legacy FiberOptics at their website. You can request an RMA number there or give them a call and ask for Stephanie.

Compact Flash Upgrade For CMA4000/4000i is a post from: OLC Fiber Splicing of Denver

An example; a loose buffer tube cable with 144 strands would have 12 tubes colored as indicated in the image below. Within each buffer tube would be 12 fiber strands using the same color scheme. Therefore, strand number 61 would be in the white buffer tube, blue fiber.

Download the Fiber Color Identification Chart

Fiber Color Identification Chart is a post from: OLC Fiber Splicing of Denver

View OTDR trace files on your PC.

Viewing OTDR Trace Files Using TraceView is a post from: OLC Fiber Splicing of Denver

If you own a older OTDR then you know how much of a hassle it is to copy trace files from the OTDR over to the PC. To put this into a little perspective, transferring a couple hundred megs of trace data off of a CMA4000 involves copying data to a floppy disk over 150 times.

And to boot it’s a manual process that take up entirely too much time!

The UPLOAD FILE(S) option on the mass storage menu of the CMA4000/4000i allows the user to select a large number of files and initiate a remote copy process without having to copy to a floppy, and then to a PC or database.

To accomplish this there are two things  that you need. A null modem cable and the software utility OTDRcopy.exe.

The null modem serial cable required is a DB-9 female to DB-9 female serial cable with a 9 pin male to female null modem.

Image courtesy Anritsu

The OTDRcopy.exe utility is a small DOS program that can run from DOS or from a DOS shell in the Windows environment. It can be found on the CMA upgrade diskette version 3.18a or later.

Follow the steps outlined below to transfer trace data files serially from the CMA (version 3.18a or higher) to a PC using the OTDRcopy.exe utility.

1. Using Windows Explorer, create a directory or subdirectory on the pc named OTDRcopy (or something easily recognized) in which the OTDRcopy.exe utility will reside. This is also the directory or subdirectory where the files will be transferred to.

2. Copy the OTDRcopy.exe file from the CMA upgrade disk to the directory or subdirectory created in step 1.

3. Connect the Null Modem serial cable from the COM B port on the OTDR to the COM 1 port on the PC.

4. Upon selecting the UPLOAD FILES(S) option on the CMA, a window will be displayed with a list of files on the current directory. Use CHANGE DIRECTORY and/or CHANGE DRIVE to bring up the desired trace file list.

5. Select the desired trace files

6. When all files are selected, or tagged, open the OTDRcopy.exe utility by double clicking on it in Windows Explorer.

7. Once open, type “FT” to begin the transfer process. The OTDRcopy utility will then begin requesting each trace file in sequence and initiate a transmission over the serial cable at 9600 BAUD RATE.

The PC will display the file name, the number of bytes, and the file checksum which is used to verify correct transmission. If a transmission is corrupt, the OTDR will attempt a second transmission.

As each file is transmitted, the OTDR begins to transmit the next select file. This continues until all the desired trace files have been transmitted.

8. Once complete, the option exists to select and transfer another group of files, or end the process by pressing ESC on the PC keyboard.

There is a replacement solution for the internal hard drive and floppy drive on the CMA4000. Read about the new CMA4000 OTDR Upgrade and avoid the time consuming process of trace file transfers.

Using OTDRCopy Utility is a post from: OLC Fiber Splicing of Denver