Horizontal Cabling for Video Surveillance Guide

Horizontal Cabling for Video Surveillance Guide 

Horizontal cabling for video surveillance connects individual security cameras from their wall outlets or mounting locations back to a main control room or telecommunications enclosure.

Complicated and particular cabling is required in video networks, especially in commercials or academic environments. The cables used in network cabling must be created from specific materials. Horizontal cabling is one of the primary cabling methods used in today’s structured cabling system.

Horizontal cabling expands from a video storage room (NVR/DVR) to the individual IP Camera outlets. It is typically installed in a star topology that connects each IP Camera to the video storage room. It consists of the I/O outlet, a consolidation point (optional), a horizontal cable, mechanical terminations, and patch cords, or jumpers, stationed in the Video storage room.

 Typically, 100 meters is about the limit for the length of a cable. And bear in mind that this standard also applies to patch leads. Of course, every kind of cabling has its own limits, but it’s important that you understand what the standards are and make sure you are properly using cables.

The environment you run your cables through can make a distance. Areas that are too hot can lead to your network to fail, which is also true of excessive moisture. The best environments for cabling are areas that are cool and dry, so if your cables are run through an area that’s excessively hot or humid, you may need to set up equipment to help adjust those conditions.  A burst steam pipe can wreak havoc on your system (yes, we’ve repaired that, too).

There are a few options when it comes to professionally installing horizontal cabling for video surveillance networks. The three options examined here are:

·       'Direct Attached', where the first terminates the field cabling with an RJ45 modular plug, and connects it directly to the camera.

·       'Jack & Patch', where the cables are first terminated to a jack or patch panel, and then connected to security devices by patch cord.

·       'MPTL', Modular Plug Terminated Link is a hybrid of the two methods above with a female jack / patch panel at the head end and an RJ45 modular plug on the far end connecting directly to the camera.

Inside this report, we explain the options, tradeoffs, and elaborate on the pros and cons of each method.

The Three Methods

Direct Attach Method: The most common method of attaching devices to a network is simply plugging each terminated end into a device. Cables are run directly to a switch and to a camera or controller in the field, using an RJ45 modular plug at both ends of the cable. Testing is performed from these plugs across the length of the single cable.

However, many cite a second more permanent method is better despite being more complex:

Jack and Patch Approach: According to the 12th Edition of BICSI's TDMM and prior, all horizontal cabling should be terminated in the closet end on a patch panel, and in the field, on a jack. Starting in later editions, this requirement was relaxed for security equipment and other installations where accessibility may be difficult or tampering may be a risk.

Connections are made from the patch panel to switch, and from the jack to device with patch cords. The resulting section of cable from patch panel to jack is called the 'permanent link'. Typically jacks are installed in a wallplate for interior cameras, and patch from the plate to the camera. In exterior applications, jacks are commonly mounted in junction boxes.

Most recently ANSI/TIA has added a hybrid approach.

MPTL (Modular Plug Terminated Link): The standard ANSI/TIA-568.2-D, published in 2018, includes a specification for horizontal cabling which is is a hybrid of both 'Jack and Patch' and 'Direct Attach' cabling methods. The standard specifies a female jack on one end and a male plug on the other end. In surveillance networks this is typically a patch panel port at the head end patched to an NVR or switch, and the far end terminated with an RJ45 modular plug connected directly to the camera. This method offers the benefit of using patch panels for organized termination at the head end with the ease of installation at the far end.

The Heart Of The Debate

Historically, the major issue driving this debate is the 'modified permanent link' which modular plugs create. Since cables are specified by standards to be terminated in the typical link fashion, testers were created to test the normal permanent link, resulting in not-quite-accurate tests when testing through a modular plug.

In 2020 this is no longer a practical concern as certifiers are equipped to test, the permanent link, full channel, and most recently MPTL.

Building automation systems have used the direct attach method for years, as it was recognized by TIA standards that in some cases a jack and patch cable are impractical or unserviceable. Current Editions of BICSI's Electronic Safety and Security design reference have come to the same conclusion.

However, it should be noted that security applications break other fundamental rules of BISCI standards, such as each outlet being mounted 18" above finished floor with two cables run to it. Security devices, just like BAS devices, are application-specific, and different standards apply while respecting original intent where possible.

Which Method Should I Use?

While, practically speaking, there is nothing wrong with any of these methods, and much is left up to preference, directly attaching plugs is generally preferred by the majority of integrators. There are two main drawbacks which may be a problem when using this method:

·       Cable flexibility: In UTP cable used for horizontal runs, each of the eight conductors (four pairs) is made from a solid copper conductor. In patch cables, each conductor is made up of multiple thin copper strands. This makes the conductor, and in turn, the entire cable, more flexible. For this reason, patch cables may be able to fit into tight domes where sharp bends are without straining or pinching the cable where solid conductor cable would have issues. Strictly speaking, however, according to standards, bend radius is four times the diameter of the cable, regardless of solid or stranded construction.

·       Modular plug construction: While Cat 5e cable is almost always 24 AWG, some manufacturers of Cat 6 and higher cables have sized conductors up to 23 AWG. Care should be taken when selecting cable/modular plug combinations, to make sure the plug is rated for the category cable being installed and will handle larger-gauge wire, or it may not work properly, or simply not at all.

Users should be aware of challenges in specific applications, as well:

Interior cameras: When installing interior cameras, the key consideration is where the camera will be mounted. If the cameras are to be wall-mounted, or in the case of warehouse or other open-ceiling environments, installing jacks is simple, either in a surface-mount or recessed box with wallplate. When using ceiling-mounted domes, however, installation is trickier. As discussed in our installation issues update, exposed connections are not allowed by code above drop ceilings. This means that, unless the dome has room enough to install a jack inside it (which is unlikely), a junction box must be provided to house the connections, making the direct attach method much simpler.

Exterior cameras: Using jacks in exterior locations can be much trickier than their interior counterparts. If using box cameras, a jack may be located in the housing. However, exterior domes are as unlikely as their interior counterparts to have enough space to locate a jack and patch cable. If an enclosure is provided, for surge protection, wireless equipment, or other needs, the jack may be located there. In most cases, however, the direct attach method will be simpler.

No matter which method is used, care must be taken during installation. Maximum cable pulling tension and not exceeding bend radii should be observed. All components should be matching category rated, including mod plug and patch cables. If all of these are followed, connections should experience few issues.

Best Practices for Installation

Outdoor Protection: Use UV-resistant or shielded (STP) cables if any portion of the horizontal run is exposed to outdoor elements or electrical interference.

Avoid CCA: Do not buy copper-clad aluminum (CCA) wire because it breaks easily and fails standard resistance tests

 REF: IPVM, John.