Need Advice - 140m Ethernet Run Between Buildings

[Reda]

Hey community,

I'm facing a technical challenge and could really use your expertise. I need to establish a wired network connection between two points 140 meters apart - well beyond the standard 100m limit for Ethernet.

Key Details:

• Outdoor installation (connecting two separate buildings)
• Requires stable, reliable bandwidth
• Must be wired (WiFi isn't suitable for this application)

Looking for real-world experience:

1. Has anyone successfully implemented a similar long-distance run?
2. What solutions actually worked in practice?
3. Any pitfalls or lessons learned I should know about?

I'm especially interested in hearing about what's worked (or failed) for others in field deployments.

Thanks in advance for sharing your knowledge!

PS: I'm aware fiber is an option, but curious about other approaches that might work with just rj45 cables.

 

[bbunge]

It would work but possibly with reduced bandwidth...

However, you risk the probable issue with dissimilarities with the electrical system between the two buildings. Fiber does not conduct and would be the better way to go.
There are also some good wireless options available today that would give you high bandwidth.

 

[degrub]

What bandwidth and reliability is required ?

Point to point 2.4 GHz can go very long line-of-sight due to the narrow beam transmission. Rain or fog is the only weather that can reduce the RF power. Otherwise, fiber, direct burial or aerial rated/designed if you need higher bandwidth. You might get 100 Mbit/s reliably using CAT 5e direct burial cable. Has to be moisture blocking cable.

Ground loop would be a real concern unless the earthing point is provided only at one of the building. The potential difference between the two grounding locations can destroy electronic gear. Single earthing unlikely to be allowed, given the distance.

Coax is another possibility, but again, you have to get the earthing of the shield correct and avoid ground loops.

Fiber is the most realistic, inexpensive solution.

 

[CaptainSTX]

Hey community,

I'm facing a technical challenge and could really use your expertise. I need to establish a wired network connection between two points 140 meters apart - well beyond the standard 100m limit for Ethernet.

Key Details:

• Outdoor installation (connecting two separate buildings)
• Requires stable, reliable bandwidth
• Must be wired (WiFi isn't suitable for this application)

Looking for real-world experience:

1. Has anyone successfully implemented a similar long-distance run?
2. What solutions actually worked in practice?
3. Any pitfalls or lessons learned I should know about?

I'm especially interested in hearing about what's worked (or failed) for others in field deployments.

Thanks in advance for sharing your knowledge!

PS: I'm aware fiber is an option, but curious about other approaches that might work with just rj45 cables.

The distance is outside specs but possibly close enough to work. Buy quality cable with solid copper conductors in the length you need and test data rate. If good enough bury/install the cable between buildings. Install Ethernet surge protectors at both ends of the cable, If possible and needed install unmanaged switches as near the beginning and end of the 140 meter run to effectively act as amplifiers.

 

[tgl]

I think you're being way too quick to dismiss the wireless approach. Point-to-point wifi like Ubiquiti's UISP gear can reach gigabit-ish throughput and will probably cost less than trenching a cable. If you do insist on a wired solution, though, I concur with the other responses recommending fiber. Copper between two separate buildings creates too many hazards.

 

[Tech9]

Point-to-point wifi like Ubiquiti's UISP gear can reach gigabit-ish

There is a new model bridge in UniFi section, can do up to 6Gbps:

Building-to-Building Bridge XG - Ubiquiti Store

A 60 GHz wireless point-to-point bridge with 10G SFP+ uplink for maximum performance.

store.ui.com

 

[tgl]

There is a new model bridge in UniFi section, can do up to 6Gbps:

Yeah, but I'd only recommend the UBB if the user wants to buy into the UniFi ecosystem. Otherwise, the 60GHz "Wave" series from the UISP product line makes more sense, IMO anyway. I've not used those models myself, but if they are like other UISP PtP radios, they don't require any extra configuration infrastructure.

 

[sfx2000]

I'm facing a technical challenge and could really use your expertise. I need to establish a wired network connection between two points 140 meters apart - well beyond the standard 100m limit for Ethernet.

Trenched Fiber - this is the way...

 

[NXIL]

However, you risk the probable issue with dissimilarities with the electrical system between the two buildings.

As bbunge says, running a copper cable between electrical gear that's on two different grounds (the two buildings are are different ground, so literally will have different grounds, maybe big, maybe small, but, electronics don't like extra current coming in from unexpected sources.

Also: lightning. If you are in an area with frequent lightning Reda, adding copper wire, either aerial or underground could result in a lot of damage if lightning strikes, even just close by (doesn't have to "hit" the copper wire.

FS.com (I do not work for them or get a kickback etc, just have heard good reports) sells custom fiber optic cables, made to order:

FS.com Deutschland - HPC, Rechenzentrum, Unternehmen, Telekom

FS ist ein globales Technologieunternehmen, das sich auf Systemlösungen für Hochgeschwindigkeitsnetze fokussiert und Produktforschung und -entwicklung, Lösungsdesign und -test sowie globale Lagerhaltung anbietet.

www.fs.com

LWL-Kabel - FS.com Deutschland

FS bietet verschiedene LWL-Kabeltypen und Verkabelungslösungen, die sich im Demo-Szenario-Labor bewährt haben, um zuverlässige Hochgeschwindigkeits-Netzwerkverbindungen für Rechenzentren und Unternehmen zu gewährleisten.

www.fs.com

https://www.fs.com/solution_design.html

I would assume you want outdoor/direct bury cable? Pretty sure they have that.

Here are some networking pros (?) talking about options:

https://www.reddit.com/r/networking/comments/1ecqfz1/alternatives_to_fscom_for_fiber_optic_cables

Here is what can happen with lightning, and copper cable between buildings, pretty good tech guy so knows his stuff, start at about 5:55

 

[CaptainSTX]

As bbunge says, running a copper cable between electrical gear that's on two different grounds (the two buildings are are different ground, so literally will have different grounds, maybe big, maybe small, but, electronics don't like extra current coming in from unexpected sources.

Also: lightning. If you are in an area with frequent lightning Reda, adding copper wire, either aerial or underground could result in a lot of damage if lightning strikes, even just close by (doesn't have to "hit" the copper wire.

FS.com (I do not work for them or get a kickback etc, just have heard good reports) sells custom fiber optic cables, made to order:

FS.com Deutschland - HPC, Rechenzentrum, Unternehmen, Telekom

FS ist ein globales Technologieunternehmen, das sich auf Systemlösungen für Hochgeschwindigkeitsnetze fokussiert und Produktforschung und -entwicklung, Lösungsdesign und -test sowie globale Lagerhaltung anbietet.

www.fs.com

LWL-Kabel - FS.com Deutschland

FS bietet verschiedene LWL-Kabeltypen und Verkabelungslösungen, die sich im Demo-Szenario-Labor bewährt haben, um zuverlässige Hochgeschwindigkeits-Netzwerkverbindungen für Rechenzentren und Unternehmen zu gewährleisten.

www.fs.com

https://www.fs.com/solution_design.html

I would assume you want outdoor/direct bury cable? Pretty sure they have that.

Here are some networking pros (?) talking about options:

https://www.reddit.com/r/networking/comments/1ecqfz1/alternatives_to_fscom_for_fiber_optic_cables

Here is what can happen with lightning, and copper cable between buildings, pretty good tech guy so knows his stuff, start at about 5:55

Lots of paths for lightning to follow into a building besides a copper Ethernet cable between buildings. First, most people probably don't have a fiber optic Ethernet drop. Most people probably have metallic coaxial cable running from the pedestal to the demarc on their home. Some people still have copper phone lines coming into their building even if they no longer use them. Living in Florida I have seen homes where lightning hit the control cables for sprinkler systems and then jumped over to the electrical system. I have also seen where lightning has hit a home's roof followed the metal ridge caps and then jumped over to both the electrical and data wiring in the attic.

 

[tgl]

If you get a point-blank lightning strike on your house, a lot of your electronics will probably be toast just from EMF, never mind whether there's a copper pathway. I think the issue about varying ground potential is the more serious concern here. (Admittedly, nearby lightning can cause what had been close-enough ground potentials to be not-close-enough.)

 

[Tech9]

@Reda has to use professional services. Their previous post was about hotel infrastructure. @sfx2000 response is correct.

New Hotel Infrustructure

Hello everyone, We’re in the planning phase of building a new hotel, and I’m seeking advice on the most efficient and scalable way to design the network infrastructure. We have two options in mind and would appreciate your professional input: Traditional setup: Running dedicated Ethernet...

www.snbforums.com

 

[CaptainSTX]

If you get a point-blank lightning strike on your house, a lot of your electronics will probably be toast just from EMF, never mind whether there's a copper pathway. I think the issue about varying ground potential is the more serious concern here. (Admittedly, nearby lightning can cause what had been close-enough ground potentials to be not-close-enough.)

Certainly, there is the potential for problems. Many people have detached garages and other out buildings all powered through the main building and manage to get by. In most cases if the power feed was done according to code and if there are problems they will be hard to diagnose but that isn't a good enough reason to try a simpler solution even if it puts a small amount of network gear at risk. Most home networking equipment doesn't even have a grounding conductor so I'm not sure it would even notice a difference in grounding potential.