2-Post Open Rack Enclosures: Specs, Assembly, and Where They Fit

Not every equipment room needs a fully enclosed cabinet. When airflow, budget, and access speed matter more than physical security, a 2-post open rack gives you the mounting capacity you need without the extra weight, cost, and heat retention of a closed frame. Vertical Cable offers three 2-post open rack enclosures built to the 19 in. standard: the compact 20 RMU 047-WOS-0220, the full-height 45 RMU 047-WOS-0245, and the 047-WOS-0245/2P — a 45 RMU rack that ships in two sections for tight delivery routes.

Here’s what’s in each one, how they go together, and where each fits in your rack strategy.

Vertical Cable’s 2-Post Open Rack Lineup

All three racks share the same 19 in. equipment width, #12-24 mounting holes, black powder-coat finish, and RU markings on the front and rear posts. The differences come down to three things: how much rack space you need, how much weight you’re mounting, and how the frame gets into the room.

Why Choose a 2-Post Open Rack Over a 4-Post

This is one of the most common questions installers weigh before ordering: open rack or enclosed cabinet, 2-post or 4-post. The honest answer depends on what you’re mounting in it.

A 2-post open rack is the right call when:

• Equipment is lightweight to moderate — patch panels, switches, and most active networking gear fall well within the 440 to 804 lb. ratings across Vertical Cable’s 2-post line
• Airflow matters more than physical security — open frames don’t trap heat the way an enclosed cabinet does, which matters in equipment rooms without dedicated cooling
• Space and budget are tight — 2-post racks have a smaller footprint and lower cost than 4-post cabinets
• Access speed is a priority — techs can reach cabling and hardware from front and rear without opening doors or removing side panels

A 4-post rack earns its place when equipment is heavier (deep servers, UPS units), when rails need to support weight at both front and rear mounting points, or when the room requires an enclosed, lockable cabinet for security or dust control. For most telecom closets, MDF/IDF rooms, and patch panel-heavy racks, though, a 2-post open frame covers the job at a fraction of the footprint.

Compatibility: The 19 in. EIA Standard

All three racks meet the 19 in. rack standard defined by EIA/ECA-310, which governs rack unit height, hole spacing, and front panel width across the industry. That means they accept any standard 19 in. rack-mount equipment — switches, patch panels, PDUs, cable managers — regardless of manufacturer.

One rack unit (RU) equals 1.75 in. of vertical space. The 20 RMU 047-WOS-0220 provides 35 in. of usable mounting height within its 40 in. frame, while both 45 RMU models provide 78.75 in. of mounting height within an 84 in. frame.

Where Each 2-Post Open Rack Fits in Your Build-Out

Choose the 047-WOS-0220 for small IDF closets, AV and security equipment, branch offices, and test labs — anywhere 20U of rack space covers the equipment list and a 40 in. frame fits the room better than a full-height rack.
Choose the 047-WOS-0245 when you need the full 45 RMU and the highest load rating in the line, and the delivery path into the room can handle an 84 in. frame.
Choose the 047-WOS-0245/2P when doorways, stairwells, elevators, or tight equipment rooms make moving a full-height frame hard to move —or when compact packaging makes it easier to stock and ship racks to multiple job sites.

Once assembled, all three are ready for standard 19 in. rack-mount gear. For vertical cable management, the 047-VMF-4502 45 RMU double-sided cable manager is listed as compatible with both the 047-WOS-0220 and 047-WOS-0245 — it ships as two 22.5U sections, so one section pairs with the 20 RMU rack. The 047-WVM-2010 20 RMU metal vertical wire manager is designed for the 047-WOS-0220. For mounting hardware or a 4-post alternative for heavier loads, Vertical Cable’s rack accessory line completes the build without mixing brands or hole patterns mid-install.

Assembly: What to Expect

The racks ships unassembled, and Vertical Cable recommends two people for the job — the frame sections are long and awkward to align solo.

Tools Required 5 mm hex key wrench — included with the rack Pliers or an adjustable wrench — required and NOT included That second tool is easy to overlook. Step 2 has you hold each nut with pliers or a wrench while tightening the bolt with the Allen key, so a tech who shows up with only the included hex key can’t fully secure the frame connection.
Assembly Steps
1. Base angle bar assembly. Attach the front and rear base angle bars to the lower vertical frame sections using the supplied hex socket bolts, plain washers, and hex nuts. Leave the hardware loose for now. Make sure the RU markings face the front of the rack — much harder to correct once the frame is square.	2. Vertical frame connection. Join the upper and lower vertical frame sections with the supplied steel mounting plates. Each connection takes two brackets: one on the outside of the frame and one on the inside, both positioned over the pre-drilled holes at the joint. Install a washer with every bolt. Hold and tighten each bolt with the 5 mm Allen key while holding the nut with pliers or an adjustable wrench, and tighten securely while keeping the upper and lower sections aligned.	3. Top angle bar assembly. Attach the front and rear top angle bars to the upper vertical frame sections with the supplied hex socket bolts, washers, and nuts. Verify that all vertical frame sections are aligned and the rack is square before fully tightening all hardware.

Anchor It to the Floor

An 84 in. 2-post frame loaded toward its 551.2 lb. capacity gets top-heavy quickly, and the base is pre-drilled for it: the top view on the spec sheet shows four 0.8 in. (20 mm) anchor holes in the base feet.

Secure the rack to the structural floor as part of the install, not as a follow-up task. In seismic zones, BICSI installation practices and local building codes may require anchoring or supplemental bracing — check your jurisdiction’s requirements before loading the rack.

Where It Fits in Your Build-Out

Once assembled and anchored, the 047-WOS-0245/2P takes any hardware built to the 19 in. EIA-310 footprint. A few things worth planning before gear goes in:

• Choose the 047-WOS-0220 for small IDF closets, AV and security equipment, branch offices, and test labs — anywhere 20U of rack space covers the equipment list and a 40 in. frame fits the room better than a full-height rack.
• Choose the 047-WOS-0245 when you need the full 45 RMU and the highest load rating in the line, and the delivery path into the room can handle an 84 in. frame.
• Choose the 047-WOS-0245/2P when doorways, stairwells, elevators, or tight equipment rooms make a full-height frame hard to move — or when compact packaging makes it easier to stock and ship racks to multiple job sites.

Once assembled, all three are ready for standard 19 in. rack-mount gear. For vertical cable management, the 047-VMF-4502 45 RMU double-sided cable manager is listed as compatible with both the 047-WOS-0220 and 047-WOS-0245 — it ships as two 22.5U sections, so one section pairs with the 20 RMU rack. The 047-WVM-2010 20 RMU metal vertical wire manager is designed for the 047-WOS-0220. For mounting hardware or a 4-post alternative for heavier loads, Vertical Cable’s rack accessory line covers the rest of the build without mixing brands or hole patterns mid-install.

45 RMU 2-Post Open Rack Enclosure | 047-WOS-0245/2P The 45 RMU, 2-post open rack enclosure is designed to organize network equipment, patch panels, and cable management. Its heavy-duty steel construction supports up to 551.2 lbs (250 kg), while the open-frame design provides convenient front, rear, and side access. It accommodates standard 19-inch EIA-310 rack-mount equipment and features a static-resistant black powder-coated finish for long-lasting durability. View Product → Category: Open Rack Enclosures

Frequently Asked Questions