Datacenter
Data center PDU and RPP commissioning field guide
Commission the last distribution stage before the rack: the PDU transformer, the RPP panels, the harmonics, the phase balance, the branch monitoring, and the A and B feeds that have to be real.
Direct answer
A data center PDU (power distribution unit) takes UPS output, often through a K-rated transformer, and distributes it to the white space. The RPP (remote power panel) is a downstream panelboard placed near the rows to shorten branch runs. Together they are the last distribution stage before the rack whip and rack strip.
Key takeaways
- The floor PDU steps UPS output through a transformer to the white space; the RPP is a transformer-less panelboard fed from the PDU near the rows.
- Data center PDUs commonly use a K-13 transformer for triplen harmonic heat, with the neutral rated at 200 percent of full-load current.
- A transformer-based PDU secondary is a separately derived system: bond neutral to ground once at the PDU, never re-bond at a downstream RPP.
- Hold each phase within about 10 percent of the others and record the phase of every branch circuit as racks fill.
- Trace every A and B feed back to separate PDUs, panels, and UPS paths; feeds sharing a source are not redundant.
What the PDU and RPP do in the power chain
A data center PDU is the floor-level unit that takes power from the UPS and distributes it to the white space, usually stepping it through a transformer on the way. The RPP, the remote power panel, is a downstream panelboard fed from the PDU and set close to the rows so the branch circuits to the racks are short. Between them they are the last distribution stage before the whip drops to the rack strip, which is the rack PDU the servers actually plug into.
Keep the three PDUs straight, because the same three letters mean three different things on a data center. The floor PDU is the cabinet covered here. The rack PDU is the power strip in the cabinet, covered in the rack readiness guide. The RPP sits between them. When a drawing or a spec says PDU, find out which one before you commission anything.
The reason this layer gets its own commissioning effort is that everything above it is proven on the power QA side and everything below it is the customer's load. The PDU and RPP are the handoff. A clean power chain that loses its discipline at the PDU, with phases out of balance, monitoring never mapped, or A and B feeds that secretly share a source, hands the IT floor a problem the whole upstream plant was built to prevent.
What is the difference between a PDU and an RPP?
The PDU is the unit with the transformer and the main; the RPP is a panelboard fed from it. A transformer-based floor PDU takes UPS output, usually 480 V, steps it through an internal transformer to the rack voltage, commonly 415Y/240 V or 208Y/120 V, and feeds a set of internal panelboards or subfeed breakers. The RPP has no transformer. It is a remote panelboard that takes one of those subfeeds and breaks it into branch circuits near the racks.
The split exists to shorten the branch runs. A single PDU in a corner feeding the whole hall would run long whips across the floor, and voltage drop and copper both climb with the distance. Pushing RPPs out into the rows, each fed by a subfeed from the PDU, keeps the branch breaker within a row or two of the rack it serves. The PDU does the transforming and the bulk distribution; the RPP does the local branch distribution.
Not every design uses both. Some halls feed racks straight off PDU panelboards or off busway with no RPP at all. Some use RPPs as the only floor-level panel, fed from a transformer somewhere upstream. Read the one-line and walk the actual gear before you assume the topology, because the commissioning scope follows the equipment that is actually installed, not the generic block diagram.
The transformer-based PDU, and the floor-mount and modular variants
The workhorse on most data center floors is the transformer-based PDU: a floor-standing cabinet holding an isolation transformer, a primary input section, a secondary main, and output panelboards or subfeed breakers, with metering and monitoring built in. The transformer is the heart of it. It isolates the secondary from the primary, steps 480 V down to the utilization voltage, and on a data center it is almost always a K-rated transformer built to take the harmonic heat the IT load throws at it, which the harmonics section covers.
The input comes from the UPS output distribution, so the PDU lives on the protected bus. The transformer secondary creates a new system, which means the PDU is a separately derived system and gets grounded as one, covered later. From the secondary, power lands on the PDU main, then splits to the internal panelboards and any subfeed breakers that feed RPPs out in the rows. The monitoring watches the input, the output, and on a good unit every branch.
The variants are worth knowing because they change the commissioning. A transformerless or static PDU skips the internal transformer, taking a utilization voltage straight from an upstream source, so there is no transformer to test but the harmonic and grounding picture moves upstream. A modular or scalable PDU lets you add output sections or branch modules as the hall fills, which is flexible to build but means you commission the unit again every time capacity is added, not once at turnover. Match the test scope to the type in front of you.
The RPP, the branch panel, and the busway alternative
The RPP is a remote power panelboard, fed by a subfeed breaker in the PDU, that lands in or near the rows to break the feed into branch circuits for the racks. It is a panelboard in the NEC sense, governed by the panelboard rules in Article 408, with a main or main-lug arrangement and a bank of branch breakers. The whole point of pushing it out from the PDU is to keep the branch runs short, which holds voltage drop down and keeps the copper bill sane on a big hall.
Commissioning an RPP is panel work. Verify the subfeed that feeds it, confirm the panel matches the schedule, check the branch breaker ratings and poles against the design, torque the terminations to the values on the gear, and confirm the branch monitoring if the RPP carries it. The RPP is small and easy to treat as an afterthought, which is exactly why its branch circuits are the ones most often left unmapped or unlabeled.
The alternative to the RPP is busway, an overhead bus with plug-in tap boxes that drops power to the racks without a fixed panel. Busway trades the RPP's fixed branch breakers for tap boxes you add and move as the row fills, which is why high-density and build-as-you-grow halls lean on it. The busway has its own commissioning, joint torque and contact resistance and infrared under load, covered in the busway guide. The choice between an RPP and busway is a design call about flexibility versus a fixed panel, and the commissioning follows whichever one is installed.
Why does a data center PDU use a K-rated transformer?
Because the IT load makes harmonics, and a standard transformer overheats on them. Every server power supply is a switch-mode supply, a nonlinear load that draws current in pulses rather than a clean sine wave. Those pulses are rich in harmonics, and the ones that matter most here are the triplen harmonics, the third, ninth, fifteenth, and so on. The triplens do not cancel in the neutral of a three-phase wye system the way the fundamental currents do. They add up arithmetically, so the neutral can carry more current than any one phase.
That is the problem a K-rated transformer is built to survive. A standard transformer sized for linear load runs hot and ages fast when the harmonic currents drive eddy and stray losses up. The K-rating, a number from 1 up through 13, 20, and beyond, says how much harmonic heating the unit is designed to take. A K-1 is a normal transformer. Data center PDUs commonly run K-13, which handles typical IT harmonic content, with K-20 available where the load is heavier and confirmed by study.
The neutral is the other half of the fix. Because the triplens stack on the neutral, the conductor and the bus have to be sized for it. The common UL listing for K-rated dry-type transformers requires the neutral to be rated at 200 percent of the full-load current, and the secondary neutral conductor is typically run oversized to match. When you commission a PDU, confirm the K-rating against the spec and confirm the neutral is the oversized one the design called for. A standard transformer or an undersized neutral quietly swapped in is a heat failure waiting for the hall to fill.
A harmonic-mitigating transformer goes further, using winding arrangements that cancel the triplen fluxes rather than just tolerating the heat, and some specs call for one instead of a plain K-rated unit. Verify which the project specified, because they are not the same animal and the submittal will say.
Why does phase balancing matter at the PDU and RPP?
Phase balancing is spreading the rack and branch loads evenly across the three phases so no single phase overloads while the others coast, and it is the number-one operational issue at this layer. Three-phase power feeds the PDU and the RPP, and the racks hang single-phase or three-phase loads off it. If the single-phase loads pile onto one phase, that leg hits its limit and trips or strands capacity while the other two sit half-used. The plant has the power; the imbalance just makes it unreachable.
Imbalance also drives the neutral. In a wye system, the neutral carries the difference between the phase currents, so an unbalanced load pushes neutral current up on top of whatever the harmonics are already adding. Balance the phases and the neutral current drops toward what the harmonics alone produce. Let them drift and you stack imbalance current on harmonic current on a neutral that is working hard already.
A common operational target is to hold the load on each phase within about 10 percent of the others, but the real number comes from the design and the breaker ratings. The discipline is to assign and record the phase for every branch circuit as the racks fill, not to balance once at commissioning and walk away. The load grows one server at a time after turnover, and the balance you proved at handoff drifts the moment the floor starts taking moves, adds, and changes. The branch monitoring is what lets the operations team watch the balance hold, which is the next section.
The branch circuit, the whip, and the A and B feeds
From the RPP or the PDU panel, each branch circuit runs through a breaker to a whip, the flexible conduit drop that lands a receptacle at the rack for the rack PDU to plug into. The breaker is sized and poled for the rack PDU it feeds, the whip is the cable to the rack, and the connector is usually a locking or an IEC type matched to the rack PDU cord. Commission the branch and you confirm the breaker rating, the conductor and whip sizing, the connector type, and that the circuit lands where the schedule says it does.
The piece that makes this redundant is the A and B feed. A dual-corded rack takes one cord from an A-side rack PDU and one from a B-side rack PDU, and those two have to trace back to genuinely separate paths: separate PDUs, separate UPS, ideally separate generator and utility paths. The whole topology exists so the rack rides through the loss of one side. The rack readiness guide covers the rack end of this in detail.
The failure mode here is the one to hunt for at commissioning. An A and a B feed that look independent at the rack but trace back to the same PDU, the same panel, or the same upstream breaker are not redundant. They are one feed wearing two cords, and they will drop the rack together on the day that one source fails. Trace both feeds back to the source on paper and confirm it in the gear. The label says A and B; the breaker schedule and the one-line have to agree that they really are.
Commissioning the PDU: transformer, terminations, and the breaker schedule
Commissioning the PDU starts with the transformer and works out to the panels. The transformer gets the acceptance tests any dry-type transformer gets: insulation resistance to confirm the windings are sound and dry, a turns-ratio test to confirm the ratio and the tap setting match the nameplate, and a check that the taps are set where the design wants them for the secondary voltage. The transformer receiving and acceptance guide covers the insulation resistance, turns ratio, and tap detail; do that work before the unit is energized, while the readings are the clean baseline.
Then the distribution. Verify the input feed and its protection, confirm the secondary main rating, and walk the breaker schedule against the as-built panel, breaker by breaker, rating and pole and circuit. Torque every termination to the value on the lug or in the manufacturer's table and mark it, because an under-torqued lug on a branch that runs continuous IT load is where heat concentrates and where the failure starts.
The last step happens energized and under load. Once the PDU is carrying load, an infrared scan of the terminations and connections finds the high-resistance joint that megged fine cold but heats up under current. The infrared scan guide covers how the scan is run and read. A loose secondary lug or a bad branch termination shows up as a hot spot long before it shows up as a tripped breaker or a smell, and on a live data hall the infrared scan is the cheapest insurance in the building.
What is branch circuit monitoring and how is it commissioned?
Branch circuit monitoring, BCM, is per-breaker current and power measurement at the PDU or RPP, so the operations team can see what every branch draws without putting a clamp on it. It rides on current transformers, one per branch, that read the current on each breaker and feed a metering board, which reports amps, volts, power, and energy per circuit up to the DCIM. BCM is how a data center watches capacity and phase balance circuit by circuit instead of guessing at the panel level.
Commissioning BCM is mostly mapping, and the mapping is where it goes wrong. Each current transformer has to be tied to the right breaker, and each breaker to the right circuit, rack, or tenant in the DCIM, so the number on the screen matches the steel on the floor. A current transformer landed on the wrong breaker, or a panel schedule typed in wrong, gives the operations team confident, precise, wrong data for the life of the building. Confirm the mapping by energizing a known load and watching the right channel move, not by trusting the schedule.
The alarm thresholds are the other half. Set a warning and a critical threshold per circuit, referenced to the breaker rating and the design load, so the team gets told before a branch reaches the breaker, not after it trips. Monitoring with no thresholds is just a log nobody reads. Monitoring mapped wrong is worse than none, because it is trusted. Map it, prove the mapping, set the thresholds, and record which CT reads which breaker reads which rack.
Functional testing under load and breaker coordination
Before the IT load exists, you prove the PDU and RPP under load with a load bank, the same way the rest of the plant is proven. Load banks stand in for the racks so you can confirm the transformer holds its secondary voltage at rated load, the terminations stay cool, and the heat rise across the unit settles where the manufacturer says it should. The load bank guide covers how the load is staged and how the results are judged. A PDU that looks fine at the trickle a half-built hall draws can still run hot at design load, which is the point of loading it.
The other thing the load test exercises is coordination. The protection has to be selective, meaning a fault on one branch trips that branch breaker and only that breaker, leaving the PDU main and the RPP main closed and the rest of the floor up. If the branch breaker lets too much fault current through before it clears, it can trip the main above it and take down a whole panel or row over a single rack's fault. That is miscoordination, and it is exactly what a data center cannot tolerate.
Selective coordination is set in the coordination study, not in the field, and commissioning verifies that the as-left breaker settings and types match the study. On adjustable trip units, confirm the settings device by device. On molded-case branch breakers, confirm the breaker is the type the study coordinated, because a fast branch breaker is often what makes the selectivity work at the fault levels a data center sees. The branch trips before the main, every time, or the redundancy upstream does not matter.
Is the PDU transformer a separately derived system?
Yes, when the PDU has its own transformer, the secondary is a separately derived system, and it gets grounded and bonded as one. A separately derived system has no direct electrical connection to the supply conductors of another system; the transformer secondary is a new source. That means the neutral-to-ground bond happens once, at the PDU, through a system bonding jumper, and a grounding electrode conductor ties the system to the building grounding electrode system. The NEC rules for grounding separately derived AC systems, commonly cited at 250.30, govern this; confirm the section against the adopted edition.
The detail that gets botched is the single bonding point. The neutral and ground are bonded together at exactly one location for the derived system, at the PDU, and nowhere downstream. Bond them again at an RPP or a downstream panel and you have created a parallel neutral path, so normal neutral current rides on the grounding system and the equipment grounds. On a data center carrying heavy triplen neutral current, that is both a code violation and a noise problem on the floor. Commission it by confirming the system bonding jumper is at the PDU and that no downstream panel re-bonds neutral to ground.
The rest is verification. Confirm the system bonding jumper is sized to the secondary conductors, confirm the grounding electrode conductor lands on the building electrode system, and confirm the equipment bonding is continuous and torqued out to the RPPs and the racks. The grounding and rack readiness work downstream of the PDU bonds every cabinet back to the common bonding network. The PDU is where the derived system's ground is established, so it is where you start.
Capacity, breaker fill, and stranded power
Capacity at the PDU and RPP is tracked two ways, and they have to agree: the amps used against the amps available, and the breakers filled against the breakers open. A PDU rated for a load can run out of breaker positions before it runs out of transformer, or run out of one phase before the other two, and either one strands capacity the building paid for. Commissioning is where you establish the as-built baseline of what is installed, what is loaded, and what is left.
Stranded capacity is the quiet money loss in a data center. A panel that looks full of breakers but is lightly loaded, or a PDU with two phases near limit and one half-used, is capacity sitting idle because the loading was never tracked or balanced. The design density set the target; the as-built loading is what actually happened as the racks went in. They drift apart fast once the floor starts filling, which is why the branch monitoring and a maintained capacity record matter more than the design spreadsheet a year on.
Track it from turnover. Record the rating, the connected load, the spare breaker positions, and the per-phase loading for each PDU and RPP, and keep it current as moves and adds happen. The operations team inherits the floor at whatever density it was left, and a PDU whose real loading nobody tracked is a PDU that either trips unexpectedly or sits stranded while a new one gets bought that was never needed.
Labeling and the circuit directory
A branch circuit nobody can trace is a circuit nobody can safely work on. The PDU and RPP have to carry a circuit directory that maps every breaker to the rack and the rack PDU it feeds, and the labels on the gear, the whips, and the receptacles have to agree with the directory and the DCIM. One naming convention, keyed to the rack coordinate, used on the breaker, the whip, the receptacle, and the record.
This is what makes a move, add, or change safe. When a tech needs to de-energize a rack feed, the directory tells them which breaker in which panel, and the label on the whip confirms it before they open anything. Mismatched or missing labels turn every MAC into a trace-it-out exercise on a live floor, which is where someone opens the wrong breaker and drops the wrong rack. The cross-connect and labeling discipline that governs the cabling carries straight into the power side: label both ends, tie it to the coordinate, keep the directory current.
Label as the gear is commissioned, not after the floor is full. A panel directory filled in from memory months later is a directory full of guesses, and the branch monitoring mapping depends on the same breaker-to-rack truth. Get the directory right at commissioning and the monitoring map, the MAC safety, and the capacity tracking all inherit it.
The PDU and RPP in the integrated systems test
The PDU and RPP are the bottom of the chain the integrated systems test proves. The integrated systems test, covered in the power QA pillar guide, drops the utility at load and watches the whole plant ride through on UPS, then generators, without dropping the critical bus. The PDU sits on the protected bus, so the load it carries is exactly the load that has to ride through, and the RPP branches are where that ride-through either holds or shows up as a dropped rack.
What the PDU layer contributes to the test is the realistic load path and the A and B proof. With load banks on the branch circuits, the integrated test exercises the actual distribution the racks will use, not just the gear upstream. Failing one source on purpose, an A-side PDU or its feeding UPS, is how you prove a dual-corded load really does stay up on the B side. If the A and B feeds secretly share a path at the PDU, this is the test that exposes it, because pulling one source drops both.
The PDU and RPP do not transfer or sequence; they are passive distribution. Their job in the integrated test is to carry the load cleanly through every event the sequence throws and to prove the redundancy drawn on the one-line is real in the copper. A plant that rides through perfectly upstream and drops a rack at the PDU because A and B were never independent has failed where it counts, at the load.
What to document
The PDU and RPP record is what the operations team runs the floor against. Capture it per unit so a reviewer can reconstruct the distribution from the paper alone: the transformer rating and tests, the input and output voltages, the per-phase loading, the branch schedule, the monitoring map, and the infrared results. The table is the spine of the turnover set for this layer.
| Record | Why it matters |
|---|---|
| PDU / RPP ID and location | Ties every branch and rack record to one unit |
| Transformer kVA, K-rating, taps | Confirms the unit handles the harmonic load and the secondary voltage |
| Input and output voltage verified | Proves the transformation and tap setting are correct |
| Per-phase load A, B, C | Documents the balance the floor starts from |
| Branch breaker schedule, as-built | The directory every MAC and trace depends on |
| Branch monitoring mapped and proven | Confirms the DCIM data matches the steel |
| Terminations torqued and IR-scanned | Proves the connections are tight and cool under load |
| A and B feed sources traced | Confirms the redundancy is real, not shared |
| Grounding: SBJ at PDU, GEC landed | Proves the separately derived system is grounded once, correctly |
| Spare breaker positions and capacity | Lets operations track loading and avoid stranding |
Common mistakes
- Leaving the phases out of balance, so one leg trips or strands capacity while the others coast.
- Accepting a standard or undersized neutral on a unit that carries heavy triplen harmonic current.
- Energizing the branch monitoring without proving the CT-to-breaker-to-rack mapping against a known load.
- Running A and B feeds that trace back to the same PDU, panel, or upstream breaker.
- Skipping the torque or the under-load infrared scan on the terminations.
- Re-bonding neutral to ground at a downstream RPP, creating a parallel neutral path on the grounding system.
- Treating the coordination study as a binder instead of verifying the as-left branch breaker settings and types.
- Filling the panel directory from memory after the floor is loaded, so the labels and the records disagree.
Field checklist
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Standards and references
The acceptance testing on the PDU transformer and the panels follows the NETA Acceptance Testing Specifications, ANSI/NETA ATS, which is the field reference for what to test on the transformer, the breakers, and the connections before energization and what the results should show. The installation itself is built to the NEC, NFPA 70: the transformer rules in Article 450, the panelboard rules in Article 408 that govern the RPP and the PDU panels, and the grounding of separately derived systems in Article 250, commonly cited at 250.30 for the system bonding jumper and the grounding electrode conductor. The neutral and harmonic-load sizing draws on the NEC neutral-conductor and load-calculation provisions; confirm the specific articles against the adopted edition.
The K-rated transformer and its 200 percent neutral come from the UL listing for dry-type transformers, and the K-factor itself follows the recognized transformer-harmonic practice. For powering and grounding sensitive electronic equipment, IEEE 1100, the Emerald Book, is the reference for the grounding, the noise control, and the harmonic handling a data center distribution needs. The Uptime Institute Tier framework drives the redundancy the A and B feeds have to deliver where a Tier is claimed.
Edition numbers and section references shift between code cycles, so confirm the specific edition and any local amendments against the project documents before citing a standard on a submittal. The coordination and arc-flash studies set the actual breaker settings, and the project specification and the manufacturer's instructions control the specific numbers. The standards give the framework; the contract documents and the listed equipment control the call.
Units, terms, and acronyms
The PDU and RPP layer carries its own vocabulary, and the same term can mean different gear depending on who is talking. The terms below are the ones that travel across the distribution, the monitoring, and the turnover record.
- PDU
- Power distribution unit; here the floor PDU with a transformer and panels, not the rack PDU strip
- RPP
- Remote power panel, a panelboard fed from the PDU and placed near the rows to shorten branch runs
- K-rated transformer
- A transformer rated to withstand the harmonic heating from nonlinear IT loads, by a K-factor from 1 up
- Triplen harmonics
- The 3rd, 9th, 15th and higher harmonics that add on the neutral instead of cancelling
- Phase balance
- Spreading load evenly across the three phases so no phase overloads and neutral current stays low
- BCM
- Branch circuit monitoring, per-breaker current and power metering reported to the DCIM
- SDS
- Separately derived system, the transformer secondary that is grounded once at the PDU
- A and B feed
- Two independent power paths to one rack from separate sources, for redundancy
- Whip
- The flexible conduit branch drop from the panel to a receptacle at the rack
FAQ
What is the difference between a PDU and an RPP in a data center?
A PDU is the floor unit with a transformer that takes UPS power and steps and distributes it to the white space. An RPP is a downstream panelboard fed from the PDU, with no transformer, placed near the racks to break the feed into short branch circuits. The PDU transforms and bulk-distributes; the RPP does local branch distribution.
Why does a data center PDU use a K-rated transformer?
Because server switch-mode power supplies are nonlinear and generate harmonics, especially triplen harmonics that add on the neutral. A standard transformer overheats on that current. A K-rated transformer is built to take the harmonic heat, commonly K-13 for typical IT load, and its neutral is rated at 200 percent of full-load current to carry the stacked triplens.
Why is phase balancing important at the PDU?
Phase balancing spreads load evenly across the three phases so no single phase trips or strands capacity while the others coast, and it keeps neutral current down. Imbalance stacks on top of harmonic neutral current and wastes capacity the plant has. A common target is holding each phase within about 10 percent, but the design and breaker ratings control.
What is branch circuit monitoring on a PDU?
Branch circuit monitoring is per-breaker current and power metering, using a current transformer on each branch, that reports amps, volts, and power per circuit to the DCIM. It lets operations watch capacity and phase balance without a clamp meter. Commissioning it means mapping each CT to the right breaker and rack and proving the map against a known load.
Is a data center PDU transformer a separately derived system?
Yes, a transformer-based PDU secondary is a separately derived system. It is grounded once, at the PDU, through a system bonding jumper, with a grounding electrode conductor to the building electrode system, commonly per NEC 250.30. Never re-bond neutral to ground at a downstream RPP, since that creates a parallel neutral path on the grounding system.
Transformer-based PDU or static PDU, which should I commission for?
A transformer-based PDU has an internal transformer to test and grounds as a separately derived system, and it handles the harmonic and voltage step at the floor. A static or transformerless PDU has no transformer, so that test and the grounding move upstream. The commissioning scope follows the type installed, so confirm which is in front of you before scoping.
How much spare breaker capacity should a PDU or RPP have?
The spare count comes from the design and the growth plan, not a fixed rule, but track both the open breaker positions and the per-phase amps so neither runs out first. A panel can fill its positions before its transformer, or overload one phase while another coasts. Record the as-built loading.
What do I do if the A and B feeds trace back to the same source?
Stop and treat the redundancy as failed, because two feeds on one source drop the rack together. Trace both feeds on the one-line and confirm they land on separate PDUs, panels, and UPS paths. If they share a path, the feed has to be re-routed before the rack is called ready.
Why does the branch breaker need to coordinate with the PDU main?
So a fault on one rack's branch trips only that branch breaker and leaves the PDU and RPP mains closed, keeping the rest of the floor up. If the branch lets too much fault current through, it can trip the main above it and drop a whole panel over one rack. Commissioning verifies the as-left settings match the coordination study.
How is a floor PDU different from a UPS?
The UPS conditions power and rides through a source loss on battery; the PDU is passive distribution downstream of it. The PDU takes UPS output, steps it through a transformer to the rack voltage, and splits it to panels and branch circuits. It stores no energy and transfers no sources, just carries the protected load to the racks.
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Codes cited in this guide
This guide is written and reviewed against the published standards below. Always confirm the current adopted edition with the authority having jurisdiction.