B-Line SB5779090YZ Eaton series open frame racks, Steel, Yellow zinc, 12-24 panel mounting holes, 75 mounting spaces, Top channel style, Seismic Zone 4, network bay closed duct rack, ASTM A1011SS

The SB5779090YZ provides 75 mounting spaces on a frame that stands 90 inches tall. That is more usable panel space than a standard 7-foot relay rack, so plan your ceiling clearance and any overhead cable runway around the 90 inch height before ordering.

The rails are punched with 12-24 panel mounting holes, which is the standard thread for EIA equipment mounting in North America. Any gear that ships with 12-24 rack screws and cage-free tapped rail mounting goes straight on. If your hardware came with 10-32 or M6 screws, you will need to swap to 12-24 fasteners.

It is built as a Seismic Zone 4 rack, the highest of the legacy seismic zone classifications, and it is UL Listed. Zone 4 construction is what specifiers call out for data rooms in high seismic regions such as coastal California. Floor anchoring to the structural slab per the engineer's detail is still part of the install.

Figure 23 inches wide and 90 inches deep on the base dimensions, with the frame standing 90 inches tall. Lay out your hot and cold aisles and door swing clearances from those numbers; the depth is what usually catches people out in a tight telecom closet.

The frame weighs 121 pounds on its own. That is a two-person lift and stand-up, and it means your floor loading calculation starts at 121 pounds before any equipment goes in the 75 spaces.

A closed duct network bay rack carries enclosed vertical cable duct as part of the bay, so patch cords and station cable are routed and contained within the frame rather than hanging off open rails. Use it where you are terminating high-density copper in a network bay and want managed, protected cable paths. A plain open relay rack is the cheaper choice when you are mounting a few pieces of active gear and managing cable with separate rings.

Yes, it is a top channel style frame, which gives you a structural channel across the top of the bay to tie ladder rack or cable runway to and to gang adjacent bays together in a lineup. Runway, butt splice kits and elevation hardware are ordered separately.

Yellow zinc plating over steel. The frame steel is ASTM A1011SS structural-quality hot rolled sheet. Yellow zinc gives corrosion protection for indoor equipment rooms and telecom closets; it is a plated finish, not paint, so it will not chip the way a powder coat can during equipment installs.

Order Eaton B-Line part number SB5779090YZ. The YZ suffix is the yellow zinc finish. Confirm the full number when matching an existing lineup, since B-Line uses the same SB57 family across several heights and finishes.