The DRZ477S is a 44U, 19-inch open frame 2-post relay rack from the DRZ4 Series, built for telecom central offices, data centers, utility networks and other mission-critical sites where certified seismic performance is required. It ships as a welded, freestanding rack with silkscreened rack unit markings on the mounting rails, making equipment positions easy to identify during installation and later service work.

Construction is 10-gauge welded mild steel rated to 2000 lb (UL2416 listed, UL File # E474597), finished in RAL9005 black powder coat that is GREENGUARD, TSCA and RoHS compliant. The reinforced design uses a structural base and a 22.75 in overall width to improve stability and side-to-side load strength, while the open frame layout keeps both sides of mounted equipment accessible for cabling and maintenance.

Overall dimensions are 84.00 in x 22.75 in x 18.00 in (2,134 mm x 578 mm x 457 mm), with 44U of 19.00 in EIA mounting space over a usable rail height of 77.12 in (1,959 mm) and a 6.00 in mounting depth. Rails are double-tapped 10-32 on EIA spacing, front and rear. The rack includes two 10-32 x 1/2 in studs inside the top and two 10-32 x 1/2 in ground studs at the front for bonding, plus side mounting and ganging provisions for cable managers and multi-rack rows.

The DRZ4 relay rack has been independently tested and certified to Telcordia GR-63-CORE Section 4.4.1 Zone 4 earthquake severity (Telcordia Report DA-1999), conforming to the requirements for no permanent structural or mechanical damage, deflection under 75 mm, natural mechanical frequency above 2.0 Hz, welded framework construction and base mounting without auxiliary support. The seismic dynamic load rating is 800 lb with a bolt-down kit. DRZ477S is made in Canada, USMCA and TAA compliant, and two racks can be combined with the Four Post Rack Kit (FPRK) to create a four-post configuration.