Panduit FRE4UBL Opticom 4RU Sliding-Tray Fiber Rack Enclosure
Overview
The Panduit FRE4UBL is a 4RU rack-mount fiber enclosure from the Opticom™ product line, engineered for structured cabling environments where density, cable protection, and field-serviceable access matter. Built from steel and finished in black, it accommodates up to 16 FAP adapter panels, 16 Opticom™ cassettes, or 32 HD Flex™ cassettes — supporting both singlemode and multimode fiber runs in the same chassis. At 6.97 inches tall by 19 inches wide by 15.63 inches deep (177 × 482 × 397 mm), it fits standard 19-inch two-post and four-post racks and terminates up to 384 individual fiber connections in a single unit. If you are consolidating a data center IDF or building out a backbone distribution frame, the FRE4UBL gives you the slot count and physical protection to do it cleanly without stacking multiple 1RU panels.
Key Features
- Up to 384-fiber capacity in 4RU: Sixteen FAP or cassette slots at 24 fibers each means you can terminate a full 384-fiber backbone count in a single enclosure. That is meaningful on a crowded patch panel shelf where every rack unit represents real estate cost and cooling overhead.
- Dual-format slot compatibility: Each slot accepts standard Opticom™ FAP adapter panels, Opticom™ cassettes, or HD Flex™ cassettes — plus FOSM splice modules. This means you are not locked into a single connector format at installation time; the chassis survives technology transitions without replacement.
- HD Flex™ doubling: Switching to HD Flex™ cassettes doubles the slot utilization to 32 cassettes in the same 4RU footprint. For high-density spine-leaf interconnects where port count is the bottleneck, this matters more than the chassis dimensions.
- Front sliding drawer + removable rear cover: The front-access sliding tray pulls forward to expose all fiber terminations without disturbing adjacent cabling — a practical advantage during moves, adds, and changes in live environments. The removable rear cover provides independent access to splice or pigtail runs from behind the enclosure.
- Steel construction: The all-steel chassis provides crush resistance and EMI shielding appropriate for a fiber enclosure handling cable runs in mixed-media racks alongside active copper infrastructure. Plastic enclosures flex; this does not.
- Both singlemode and multimode support: The FRE4UBL accommodates both fiber types in the same enclosure. That is useful in campus backbone environments where OS2 singlemode connects buildings and OM4/OM5 multimode serves local horizontal runs — the chassis does not dictate which FAPs you populate.
- TIA standards compliance: Designed to meet TIA structured cabling requirements, so the installation documentation holds up to third-party audits and enterprise compliance reviews. Relevant for healthcare, financial, and government facilities with mandatory structured cabling standards.
- 19-inch rack-mount form factor: At exactly 19 inches wide, the FRE4UBL mounts in any standard EIA-310 rack or cabinet without adapter hardware. The 15.63-inch depth fits most mid-depth two-post open-frame racks; verify cab depth on shallow-profile wall mounts.
Integration & Compatibility
The FRE4UBL is designed around Panduit's Opticom™ cassette and FAP ecosystem. Populate it with LC, SC, MTP/MPO, or ST adapter panels depending on the connector types in your structured cabling plant. The 16-slot chassis accepts Opticom™ FAP adapter panels and cassettes as well as HD Flex™ cassettes for higher-density deployments. FOSM splice modules drop in for mid-span splice consolidation points. The enclosure itself is passive — no power, no active electronics — so integration into any rack environment is purely a matter of physical compatibility with your chosen FAP and cassette formats. Confirm cassette part numbers against the Panduit Opticom™ catalog to match connector type and fiber mode to your installed plant before ordering.
Frequently Asked Questions
Q: How many fiber connections can the FRE4UBL terminate at full population?
A: With 16 FAP adapter panels or Opticom™ cassettes populated at 24 fibers each, the FRE4UBL supports up to 384 fiber terminations in 4RU. Using 32 HD Flex™ cassettes increases density further in the same chassis footprint.
Q: What rack sizes does the FRE4UBL fit?
A: The enclosure is 19 inches wide and designed for standard EIA-310 19-inch racks. It occupies 4 rack units (6.97 inches tall) and is 15.63 inches deep — verify that your rack or cabinet has sufficient front-to-back clearance before installing.
Q: Does the FRE4UBL support both singlemode and multimode fiber?
A: Yes. The chassis itself is fiber-type agnostic. The fiber type is determined by the FAP adapter panels or cassettes you install. Mix singlemode and multimode FAPs in the same enclosure if your cabling plant requires both.
Q: Can I access fiber terminations from both the front and rear of the enclosure?
A: Yes. The FRE4UBL includes a front-access sliding tray that pulls forward to expose connectors and a removable rear cover for independent rear access. This dual-access design simplifies splicing and patching in live environments without disturbing adjacent gear.
Q: What cassette formats are compatible with the FRE4UBL?
A: The enclosure accepts Opticom™ FAP adapter panels, Opticom™ cassettes, HD Flex™ cassettes, and FOSM splice modules. Confirm specific part numbers with the Panduit Opticom™ cassette catalog to match connector type and fiber mode.
Q: Is the FRE4UBL TIA compliant?
A: Yes. The FRE4UBL meets TIA structured cabling standards, supporting documentation requirements for enterprise and regulated-industry installations.
The FRE4UBL's 16-slot chassis is the detail that matters most in a dense IDF build. At 384-fiber capacity in 4RU — and the ability to double that to 32 HD Flex™ cassettes — this enclosure handles backbone consolidation points that would otherwise require two or three 2RU panels stacked and eating your patch space. I deploy the FRE4UBL in MDF and IDF closets where the fiber count is real, not aspirational.
Technical Highlights:
- 384-fiber termination capacity: Sixteen 24-fiber slots in 4RU. That covers a full 24-strand MTP backbone at 16 runs — useful for spine-leaf interconnect frames where you want all backbone terminations in a single lockable chassis, not scattered across eight 1RU panels.
- HD Flex™ doubling to 32 cassettes: Swapping standard cassettes for HD Flex™ modules doubles the slot count in the same 4RU space. If port density is the binding constraint — data center top-of-rack consolidation, for example — this gives you a migration path without a new enclosure.
- Dual-access design (front tray + rear cover): The sliding front tray lets a technician pull terminations forward during a live MAC without rerouting adjacent cabling. The independent rear cover matters in two-post open-frame racks where rear cable management can't be disrupted during work hours.
Deployment Considerations:
- At 15.63 inches deep, verify your two-post open-frame rack has at least 16 inches of usable front-to-back depth before ordering. Shallow-profile wall-mount enclosures typically won't fit this chassis without a spacer kit.
- The FRE4UBL ships as an empty chassis — FAP adapter panels, cassettes, and splice modules are ordered separately. Factor the cassette part numbers and fiber-mode matching into your BOM before the rack goes live.
This enclosure is a natural fit for structured cabling consolidation points in campus MDF rooms and data center IDF rows where fiber count exceeds what a panel array can manage cleanly — particularly in healthcare and financial facilities where TIA compliance documentation is a hard audit requirement.
