New Fiber Run

[R. Rod]

Hello,

After some debate and consideration, I have decided to connect 2 properties that are ~150ft apart from each other using fiber.
This would be my first time dealing with fiber, so I would like to tap into your experiences and knowledge here.

My plan is to buy a pre-terminated cable from Fiber Optic Pre-Terminated Assemblies| Ethernet Cable| Electrician Tool Kits| LANshack.com to connect the switches on each location.
I'm planning to buy an outdoor-rated (gel-filled) cable and bury it inside conduit.

Specific questions:

1. Planning to buy OM1, probably 4 strands for redundancy if I ever need it. Any problems with this? Would you get anything else?
2. Any problems with the provider? Would you get the cable from somewhere else?
3. Where can I get the conduit? I see Lowes has up to 100ft, but I don't know if there are better places to buy from.
4. How deep should I bury the conduit and cable? Does it matter?

Any other thing my rookie self should be aware of before embarking on this adventure?

Thanks!
R.

 

[bp2008]

There's a lot to learn about fiber optics. It is tough to learn on your own, so I will try to guide you.

First thing you should know is there are two main types of fiber optic cable. Multi Mode is good for about 200-300 meters range and is commonly used for short range connections. Single Mode is good for 10+ KM but can also be used for the same short runs as Multi Mode.

Multi mode fiber cables are normally found in 4 different grades, OM1, OM2, OM3, OM4, where OM1 is worst and OM4 is best. OM3 is typically recommended as the minimum if you ever want to use it for 10 Gbps networking. I would not buy OM1.

Single mode fiber cables have only 2 common grades, OS1 and OS2. Again the higher number is better, so it is ideal to skip OS1 and buy OS2.

Fiber optic cables do not typically plug directly into routers, switches, or network cards. You need a device with an SFP or SFP+ slot. You put a transceiver in the slot, and connect the fiber to the transceiver. SFP is for 1 Gbps. SFP+ is for 10 Gbps. You need to match up the transceiver type with the fiber type. So if you get multi mode fiber, you need multi mode transceivers. Multi Mode is supposed to be a bit cheaper, but in my experience the opposite is often true. Used or overstocked transceivers can be had on ebay for less than $10 each which is a great discount especially when buying a lot of them.

As far as connectors on the ends of the fiber, there are many choices. LC is the most common type for home or small business networking because the ends are small enough to fit two in one transceiver without exceeding the physical width of the transceiver. There are also two kinds of LC connector, one called "UPC" (by far the most common) and one "APC" which has slightly angled connectors which is far less common. So if in doubt, buy fiber with LC UPC connectors.

You'll also note that most fiber cables are "duplex" meaning there are two strands of fiber. This is because most transceivers send and receive on different strands, so you need two strands for a complete connection. Some transceivers avoid this need and use only one strand for both sending and receiving by using a different wavelength of light for each direction. Duplex LC connectors are really just two regular LC connectors with a plastic clip holding the two together at the appropriate distance to be plugged into a transceiver.

If you are doing a difficult fiber run that would be costly to re-do, it may be wise to install more strands of fiber than you think you will need, or even multiple separate cables, just in case any of the strands break.

 

[R. Rod]

Thanks a ton for your reply and the amount of information in it.
To your points:

• I'm going to look at OM3, I don't think I'm going to need anything more than 1Gb in a long time, but it wouldn't hurt to future-proof (if the cost is right). This is a remote location, I currently have 60Mpbs internet there.
• I have 2 NetGear GS110TP switches for cameras at each location (which are SFP capable).
  • I know some people wouldn't touch Netgear, but they have been working fine. If I ever replace them I'm going to use Ubiquiti, which also uses LC connectors.
  • I have included an image of the supported SFP connectors these switches use.

Any idea about the depth at which I should bury the conduit?

 

[R. Rod]

I just confirmed the cost of going from OM1 to OM3 is marginal - thanks for the info.

 

[sebastiantombs]

Typically three feet down is the "correct" depth. The idea is to get below the frost line so that can vary to much deeper in colder climates. In reality, here in NJ, I went down two feet and I'm very confident that will be fine for a long, long, time.

Check Home Depot as well for conduit. Local electrical supply stores are another option. Conduit prices, like everything else, seem to have skyrocketed over the last year. I'd also plan on one size larger than actually needed. That will make any turns easier to pull, the actual pull very easy and give you some room just in case you need to add something else. Leaving a pull string/rope in place is also a good idea. At 150 feet that's quite a pull to do manually without a mid-point access but it is certainly doable.

 

[R. Rod]

Typically three feet down is the "correct" depth. The idea is to get below the frost line so that can vary to much deeper in colder climates. In reality, here in NJ, I went down two feet and I'm very confident that will be fine for a long, long, time.

Apologies for the ignorance of my question but, is this because fiber is more susceptible to temperature changes? Or to prevent the cable and conduit from breaking?
I'm asking because the ISP in the same zone didn't really pay too much attention to burying their cables deep enough - heck, sometimes you can actually see them in the surface of the roads. They are coax though, not sure if different.

Check Home Depot as well for conduit. Local electrical supply stores are another option. Conduit prices, like everything else, seem to have skyrocketed over the last year. I'd also plan on one size larger than actually needed. That will make any turns easier to pull, the actual pull very easy and give you some room just in case you need to add something else. Leaving a pull string/rope in place is also a good idea. At 150 feet that's quite a pull to do manually without a mid-point access but it is certainly doable.

I was planning to have 3 segments of 50ft to make it easier and then seal the conduit (not sure how yet) to make it waterproof in those joints.
Again, maybe a stupid/rookie approach

 

[sebastiantombs]

The frost line "rule" is part NEC and part the physics of ground heave that can eventually cause the conduit to break, even rigid conduit. On a run like that I'd use PVC. Breaking it at 50 feet is fine, 75 feet (so there's only one break) would work just as well. I've pulled ~100 feet, plus, working alone. It's a PITA, sure, because you need to make sure nothing kinks as you pull. That requires going back and forth between the feed and pull ends to keep an eye on everything.

The problem with breaks is when you pull the fiber/cable you need to pull the full length out, then pull to the next break doing the same thing. Then you need to properly join the two pieces before proceeding to the next break. Using a pull box, even a condulet, makes it a lot easier but introduces another point of potential failure that can allow water to seep in.

All the joints, assuming PVC, should have prep and adhesive properly applied. If you want to make double sure, wrap each joint with a self amalgamating tape, like Coax Seal, then tape with 3M 33+ and then add a coat or two of rubberized paint. Each successive layer should project beyond the layer below it. Doing all that also means keeping the joints clean while you're working which is yet another PITA.

One other comment is to use cable that is already rated for direct burial. The reason being that type cable is already water proof or resistant. Even a sealed conduit run will, eventually, end up with water in it from simple condensation. Think of using weather resistant cable as an insurance policy.

Another tip. If you make it one continuous run, use a shop vac on one end and a slightly crumpled ball of plastic bag attached to a string, like nylon mason twine, to pull an initial pull string through. Then use that pull string to pull a piece of 1/8" or 1/4" nylon rope through. Use the rope to pull the cable.

 

[R. Rod]

The frost line "rule" is part NEC and part the physics of ground heave that can eventually cause the conduit to break, even rigid conduit. On a run like that I'd use PVC. Breaking it at 50 feet is fine, 75 feet (so there's only one break) would work just as well. I've pulled ~100 feet, plus, working alone. It's a PITA, sure, because you need to make sure nothing kinks as you pull. That requires going back and forth between the feed and pull ends to keep an eye on everything.

The problem with breaks is when you pull the fiber/cable you need to pull the pull length out, then pull to the next break doing the same thing. Then you need to properly join the two pieces before proceeding to the next break. Using a pull box, even a condulet, makes it a lot easier but introduces another point of potential failure that can allow water to seep in.

All the joints, assuming PVC, should have prep and adhesive properly applied. If you want to make double sure, wrap each joint with a self amalgamating tape, like Coax Seal, then tape with 3M 33+ and then add a coat or two of rubberized paint. Each successive layer should project beyond the layer below it. Doing all that also means keeping the joints clean while you're working which is yet another PITA.

One other comment is to use cable that is already rated for direct burial. The reason being that type cable is already water proof or resistant. Even a sealed conduit run will, eventually, end up with water in it from simple condensation. Think of using weather resistant cable as an insurance policy.

Another tip. If you make it one continuous run, use a shop vac on one end and a slightly crumpled ball of plastic bag attached to a string, like nylon mason twine, to pull and initial pull string through. Then use that pull string to pull a piece of 1/8" or 1/4" nylon rope through. Use the rope to pull the cable.

Thanks! A lot of useful tips!

 

[looney2ns]

I sure wouldn't take any "lessons" from how the Telco or cable tv contractors bury cable/fiber.
In most case's, they simply do it the easy way, not necessarily the correct way.

 

[R. Rod]

The frost line "rule" is part NEC and part the physics of ground heave that can eventually cause the conduit to break, even rigid conduit. On a run like that I'd use PVC. Breaking it at 50 feet is fine, 75 feet (so there's only one break) would work just as well. I've pulled ~100 feet, plus, working alone. It's a PITA, sure, because you need to make sure nothing kinks as you pull. That requires going back and forth between the feed and pull ends to keep an eye on everything.

The problem with breaks is when you pull the fiber/cable you need to pull the full length out, then pull to the next break doing the same thing. Then you need to properly join the two pieces before proceeding to the next break. Using a pull box, even a condulet, makes it a lot easier but introduces another point of potential failure that can allow water to seep in.

All the joints, assuming PVC, should have prep and adhesive properly applied. If you want to make double sure, wrap each joint with a self amalgamating tape, like Coax Seal, then tape with 3M 33+ and then add a coat or two of rubberized paint. Each successive layer should project beyond the layer below it. Doing all that also means keeping the joints clean while you're working which is yet another PITA.

One other comment is to use cable that is already rated for direct burial. The reason being that type cable is already water proof or resistant. Even a sealed conduit run will, eventually, end up with water in it from simple condensation. Think of using weather resistant cable as an insurance policy.

Another tip. If you make it one continuous run, use a shop vac on one end and a slightly crumpled ball of plastic bag attached to a string, like nylon mason twine, to pull an initial pull string through. Then use that pull string to pull a piece of 1/8" or 1/4" nylon rope through. Use the rope to pull the cable.

Hello,

A quick update and more questions

After measuring, calculating costs, and getting closer to the actual project and actual effort, I have decided to use a direct burial cable instead. This is why

• I really don't want to deal with conduit at this point.
• I would like the cable to be protected from rodents and have some crush resistance.

Going with armored pre-terminated cable means I would need to do bonding and grounding.
In other groups, others have recommended all-dielectric armored cables to remove the grounding concerns, but I haven't been able to find pre-terminated cables like these in lanshack, discount low voltage or fs.

Back to direct-burial-armored cables. I'm considering:

• Direct Burial Fiber Optic Assembly | Pre-terminated Fiber Assembly | Armored Direct Burial Fiber
• Thin Armored Fiber Optic Assembly | Outdoor Direct Bury Fiber Assembly | Micro Armor Fiber

My plan is to terminate in a box, bond, and ground properly... and then run a patch to my network closet inside each property.

Questions

1. Do you see any issues with this approach? Any concerns? (mainly about bonding and grounding)
2. Any recommendations on what patch cables to use?

Apologies for the amount of content and questions... but trying to make the least amount of mistakes as possible.
Especially the costly ones.

Thanks!
R.

 

[sebastiantombs]

Bonding a fiber cable isn't important at all. That's one of the points to fiber, it is non-conductive so there is no surge hazard to begin with. The armoring is to help prevent, but not stop, accidental damage from shovel. Nothing will stop damage from a back hoe.

Use CAT6 patch cables. Stranded if short, solid copper is longer. Do not use CCA, copper clad aluminum.

 

[R. Rod]

Bonding a fiber cable isn't important at all. That's one of the points to fiber, it is non-conductive so there is no surge hazard to begin with. The armoring is to help prevent, but not stop, accidental damage from shovel. Nothing will stop damage from a back hoe.

Use CAT6 patch cables. Stranded if short, solid copper is longer. Do not use CCA, copper clad aluminum.

Interesting comment on bonding and grounding. My understanding is that it is required by code to prevent hazards (shock, fire, etc) if the metal cover enters in contact with a source of electricity/
I read this StackPath

Apologies, I meant fiber patch cables to go from the termination box to the closet.
Since I'm not familiar with fiber, I'm not sure if I should be looking at anything specific.

 

[sebastiantombs]

My feeling with fiber is that the sheath is basically useless to prevent any breaks from damage. I know I use a shovel hard enough that at the very least, the sheathed cable would be kinked to the point of breaking the fiber to begin with unless they have some new style sheath. All bets are off if it's hit with a vibratory plow or back hoe. If you use un-sheathed direct burial bonding, for any reason, is a non issue and one less thing to worry about.

Patch cables need to match the mode of the cable used for the main run.

 

[R. Rod]

My feeling with fiber is that the sheath is basically useless to prevent any breaks from damage. I know I use a shovel hard enough that at the very least, the sheathed cable would be kinked to the point of breaking the fiber to begin with unless they have some new style sheath. All bets are off if it's hit with a vibratory plow or back hoe. If you use un-sheathed direct burial bonding, for any reason, is a non issue and one less thing to worry about.

Patch cables need to match the mode of the cable used for the main run.

Yep, understood.

Unfortunately, I haven't found any direct-burial rated cable that is not armored with either aluminum or steel.
I would really hate myself if after using regular OSP, a rodent decides it is a good idea to have a piece of the run for lunch...

I'm not expecting any digging around the area (this is in the middle of the woods) but I do understand your point about the risks.

Thank you a ton for your help @sebastiantombs. It is great to have people around here with your experience!

 

[bp2008]

Fiber optic cable is a "cable".

 

[Flintstone61]

Maybe get a utility marking company to see if you have buried gas or electric, telephone lines along the path.
My Buddy and I ran into phone lines, with a trencher for irrigation. Supposed to be x number of inches down, we were pulling at 18 inches.... and stopped to hand dig as we went across gas and electric markings in the grass. the Sod guys must dropped the Sod right over the phone lines. they were never buried. literally 2 inches under ground.

 

[R. Rod]

Maybe get a utility marking company to see if you have buried gas or electric, telephone lines along the path.
My Buddy and I ran into phone lines, with a trencher for irrigation. Supposed to be x number of inches down, we were pulling at 18 inches.... and stopped to hand dig as we went across gas and electric markings in the grass. the Sod guys must dropped the Sod right over the phone lines. they were never buried. literally 2 inches under ground.

Yes, that is a good suggestion for sure. I will get it done.
Thank you!

 

[Valiant]

Some transceivers avoid this need and use only one strand for both sending and receiving by using a different wavelength of light for each direction

I've found Dahua do this when interconnecting their switches. It's a bit of a pain because I've needed to purchase a DIFFERENT model SFP on each end.

Other experience I've had is that Cisco like to 'force' you to use their SFP's which can be very expensive, but it can be overridden in the CLI.

 

[Teken]

My feedback is from the perspective of installation and long term reliability. Hire or rent a ditch witch as once you break 25 feet at 3 feet depth it’s back breaking work! Insure the pit uses and is covered by the correct aggregate and sand.

Leave flag (danger) tape at the top so anyone who digs later will know something is there!

Remove any roots from the area because it’s going to be a real problem later! The depth used is mandated by the type of cable in use and the local codes enforced if present. Your not going to install unprotected cable at 18” vs 3’ or deeper. Conversely you won’t be going 3’ when direct burial cable is in use when code indicate 18” is fine!

Pick up the phone and call before you dig. I’ve never heard of anyone complain or have regrets digging deeper. That can’t be said when the inspector comes around and tells you that 18” you dug for 150’ run?!?

Guess what - you have the privilege of doing it all over again!!

Do it right once . . .

 

[crw030]

Is the commitment to fiber a personal or environmental choice? I ask because depending on the bandwidth requirements you might also be able to just create a point to point wireless link if line-of-sight is clear.

Nothing wrong with running fiber 150 feet, but trenching, burying, buying direct burial fiber, converters for both ends etc if you don't need high-bandwidth (1Gb+) or extremely high reliability.