Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
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title: Raised Access Flooring
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# Environmental and Service Conditions {toc}
−## The raised access floor shall perform under the service conditions of the occupancy it serves; data halls, battery rooms, and offices impose different load, airflow, and finish demands that drive system selection. {note}
+## The raised access floor shall perform under the service conditions of the occupancy it serves; data halls, battery rooms, and offices impose different load, airflow, and finish demands that drive system selection.
## Occupancy {toc}
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# System Configuration {toc}
−## The complete system is defined by four coordinated decisions: finished floor height, understructure type, panel core, and finish. These decisions are interdependent and shall be resolved together. {note}
+## The complete system is defined by four coordinated decisions: finished floor height, understructure type, panel core, and finish. These decisions are interdependent and shall be resolved together.
## Finished Floor Height {toc}
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### Where the finished floor height exceeds approximately 12 in, the system shall be of the bolted stringer type to provide lateral stability, and seismic bracing shall be provided where the Seismic Design Category requires it.
−### The plenum depth required for underfloor air distribution shall be coordinated with the mechanical engineer because air volume, panel open area, and plenum depth are solved together in the airflow design. {note}
+### The plenum depth required for underfloor air distribution shall be coordinated with the mechanical engineer because air volume, panel open area, and plenum depth are solved together in the airflow design.
## Understructure Type {toc}
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# Structural Performance {toc}
−## The structural performance of a raised access floor is defined by several distinct load metrics, each measured by a separate CISCA test procedure; these metrics are not interchangeable and each shall be satisfied independently. {note}
+## The structural performance of a raised access floor is defined by several distinct load metrics, each measured by a separate CISCA test procedure; these metrics are not interchangeable and each shall be satisfied independently.
## The single most common structural request for information arises from confusing concentrated load with uniform distributed load; a panel rated for a given point load may have an entirely different uniform load capacity, so both shall be scheduled and verified. {note}
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## Ultimate Load {toc}
−### The ultimate load is the safety margin above the working concentrated load; the panel shall not collapse below it. {note}
+### The ultimate load is the safety margin above the working concentrated load; the panel shall not collapse below it.
### Each panel shall sustain an ultimate concentrated load of not less than three times the scheduled concentrated load rating without structural failure per CISCA test procedure.
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### Where carpet tile finish is specified, the finish shall be evaluated for compressive resistance per ASTM F970 to confirm it does not deform under sustained equipment loading.
−### Bare or powder-coated steel finish is used only in plenum or sub-floor areas that are not walked on; it shall not be specified for occupied walking surfaces. {note}
+### Bare or powder-coated steel finish is used only in plenum or sub-floor areas that are not walked on; it shall not be specified for occupied walking surfaces.
## Electrostatic Discharge Control {toc}
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### The static-dissipative finish shall be electrically connected to the pedestal understructure so that accumulated charge drains to ground; the finish grounding path shall be continuous across the floor.
−### Electrostatic finish grounding drains charge from the walking surface and is not equivalent to equipment grounding of the understructure; the two are separate systems and shall both be provided where required. {note}
+### Electrostatic finish grounding drains charge from the walking surface and is not equivalent to equipment grounding of the understructure; the two are separate systems and shall both be provided where required.
# Airflow Panels {toc}
## Where the plenum serves underfloor air distribution, a portion of the floor is replaced with airflow panels that deliver conditioned air to the space; their quantity, open area, and damping are coordinated with the mechanical design and specified here. {note}
−## Airflow panel selection is a mechanical coordination task, not an independent finish choice; the percentage of airflow panels and their open area shall be confirmed against the airflow model before the panel schedule is finalized. {note}
+## Airflow panel selection is a mechanical coordination task, not an independent finish choice; the percentage of airflow panels and their open area shall be confirmed against the airflow model before the panel schedule is finalized.
## Airflow Panel Open Area {toc}
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# Grounding and Bonding {toc}
−## A conductive understructure can serve as a signal reference grid and as part of the equipment grounding path; where it does, it shall be bonded in accordance with the National Electrical Code and [[sync/grounding-and-bonding]]. {note}
+## A conductive understructure can serve as a signal reference grid and as part of the equipment grounding path; where it does, it shall be bonded in accordance with the National Electrical Code and [[sync/grounding-and-bonding]].
## Where the floor is used as a signal reference grid or equipment grounding path, all non-current-carrying metal parts of the understructure, including pedestals and stringers, shall be bonded to the equipment grounding conductor in accordance with NEC Article 250 and Article 645.
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# Seismic Bracing {toc}
−## In moderate and high seismic design categories the raised floor is a nonstructural component that must be braced against lateral earthquake loads; bracing hardware is not included in base system pricing and shall be specified explicitly to avoid value-engineering deletion and code non-compliance. {note}
+## In moderate and high seismic design categories the raised floor is a nonstructural component that must be braced against lateral earthquake loads; bracing hardware is not included in base system pricing and shall be specified explicitly to avoid value-engineering deletion and code non-compliance.
## Seismic bracing shall be provided where the project's Seismic Design Category is C through F, in accordance with ASCE 7 Chapter 13 and the IBC.
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# Installation {toc}
−## Installation shall not begin until the structural slab has been cleaned, leveled within tolerance, and accepted, because pedestal adhesive bond and finished floor flatness both depend on slab condition. {note}
+## Installation shall not begin until the structural slab has been cleaned, leveled within tolerance, and accepted, because pedestal adhesive bond and finished floor flatness both depend on slab condition.
## The structural slab shall be clean, dry, and free of laitance, curing compounds, and debris before pedestal adhesive is applied.
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# Spare Parts {toc}
−## Spare panels and accessories shall be furnished so that damaged panels can be replaced in service without waiting for new production, which can interrupt operation of a live data hall. {note}
+## Spare panels and accessories shall be furnished so that damaged panels can be replaced in service without waiting for new production, which can interrupt operation of a live data hall.
## The Contractor shall furnish attic stock of full panels, airflow panels, and pedestals of each type and finish installed, in the scheduled quantity as a percentage of the installed count.
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## Spare panels shall match the installed panels in type, finish, and load rating, and shall be delivered in protective packaging labeled for storage.