Fiber Optic Cabinets, Cables, Pedestals and Terminals

Because both multi-dwelling unit (MDU) and multi-tenant unit (MTU) buildings vary greatly in design and number of units, they pose a challenge to both the designer and the installer. Getting fiber to each unit…whether a living unit or a business…can be unnecessarily complex.

Before diving into the deployment, designers and installers should consider a few questions.

1. What type of building environment is this?

MDUs/MTUs can be broken down into several categories. A high rise (10 floors and higher) has lots of riser space; equipment closets are typically on every floor, giving you a place to mount your equipment or your connection points on each floor and then take your fiber into the suite. A mid rise (about 3-10 floors) typically has some type of riser space so you can pull fiber or microduct through and then from the wiring closet to the suite. A low rise or garden style environment (up to about 3 floors) doesn’t have a lot of room or any riser closets or equipment rooms, so your approach is often to penetrate the unit from the outside.

2. What are the common lengths from the equipment room to the living units?

Considering some measurements now will save you time later. These don’t have to be exact lengths (more on that later), but getting a general idea helps. Look for common averages in length as a start. Especially note very long (custom) lengths because they will need extra attention.

3. What are the local fire codes?

It’s important to find out and follow your area’s fire codes when choosing the appropriate products; fire safety requirements vary according to the installation. Is plenum rating needed? Plenum-rated cables are specifically manufactured to be used in the indoor plenum space (the part of a building that facilitates air circulation for heating and air conditioning systems). The special plenum material has a fire-retardant coating so that if a fire occurs, it will not give off toxic gasses. Is riser rating needed? Riser-rated cables run between floors in non-plenum areas. The fire requirements on riser cables are not as strict as the requirements on plenum cables.

After the previous questions are answered, consider your solutions. One that we recommend is cable in conduit (CIC), a conduit with cable pre-installed. Using CIC reduces both the time required to design and the time to install by eliminating the need to engineer exact lengths.

A benefit of using CIC is that the installer places both the conduit and the cable at the same time…as opposed to first placing the conduit and returning later to pull in the fiber. Using CIC saves the installation crews’ time, which saves money for the provider.

The drawback of most industry CIC is that the fiber typically would not have any connectors on it, so the installer must add a return trip to splice the fiber into the customer premise or splice on a connector in order to connect to the customer equipment.

Clearfield®’s FieldShield® D-ROP cable assembly eliminates this return trip by providing a pre-connectorized fiber small enough to allow an installation tech to remove excess conduit over the connected end of the fiber. This allows the installation to be a true one-pass solution. The remaining fiber is flexible and provides for easy storing of slack…so that while the individual runs of fiber to the living room can vary, exact lengths are not needed. D-ROP comes ready to place in both the outside plant (OSP) environment and the inside plant (ISP) environment with either a 3mm outside rated cable or a 2mm indoor rated cable.

FieldShield D-ROP – Direct Bury’s integrated tone wire simplifies ground locating in direct bury applications. Its industry-standard orange color provides high visibility. FieldShield D-ROP – Riser Rated comes in industry-standard beige and is designed for applications designated as riser air space.

When ready, the designer:

  • Selects the appropriate D-ROP for the building environment (high rise, mid rise or low rise)
  • Establishes commonly used cable lengths for their building environment
  • Evaluates if any type of rating is required (plenum- versus riser-rated)
  • Orders the proper amount of cable for delivery to the job site

Because D-ROP is pre-connectorized and pre-installed into the microduct, the installation crews only need to pull the assemblies to the proper living unit, trim the outer duct to length and plug the connectorized end into the appropriate port. No return trip is needed to install the fiber or to splice. Everything is completed in one pass…reducing both labor and design costs for the deployment.

As you look for ways to maximize installations in your MDU/MTU environments, consider the benefits of FieldShield D-ROP and we invite you to reach out to Clearfield. We have tons of experience with MDU/MTU deployments and are happy to help.