Evolving Migration of Power Distribution From Under ‐‐ …€¦ · · 2010-12-16Evolving...
Transcript of Evolving Migration of Power Distribution From Under ‐‐ …€¦ · · 2010-12-16Evolving...
Evolving Migration of Power Distribution Evolving Migration of Power Distribution From Under From Under ‐‐ floor floor
to Overheadto Overhead
David Skeans
Universal Electric
USA
IntroductionIntroductionHello, Good (state time of day), My Name is (state name)Having achieved the degrees of PhDPPT ; I am now considered an expert in PowerPoint presentations
so please rest assured that I will not be making the following amateurish mistakes:so please rest assured that I will not be making the following amateurish mistakes:• Using words I cannot properly pronounce• Putting everything word I intend to say on the slide which eliminates the need to memorize but
makes the presentation crowded, wordy and boring and generally causes the speaker to lose the audience before completion of the first slideaudience before completion of the first slide
• Keeping my back to the audience• Falling to us spiel chuck• Having my zipper down
– ExcessiveExcessive– Use – of – Bull
Et– Et– Points
And of course attempts at humor that are obviously not amusing
Critical Power Distribution at the rack l llevel
This discussion addresses only the addresses only the distribution system from the PDU to the racks.racks.
This part of the power delivery system has y ynot historically been a strategic focus by most major suppliers although it is critical .
Busway TypesBusway Types
Common Name Basic Function Design Type Benefits Typical ApplicationBus Bar Power
TransmissionAir insulated, flat conductor
High current & momentary
Substation
Bus Tube Power Transmission
Air insulated tubular conductor
High current & momentary, high
Substationy, g
mech strengthSandwich Bus Bar Power
TransmissionMultiple, individually insulated
High current & momentary, compact
Building risers & service entrance
conductorp
Busway (bus bar trunking)
Power Distribution Insulated flat conductor in Al or steel housing
Compact, multiple fixed access points
Manufacturing, industrial, commercialg
Bus Track (Busway) Power Distribution Insulated profiled conductor in Al housing
Compact, lightweight, continuous access distribution points
Data Center, Laboratories
p
Data Center Power Delivery system
Boa
rd STS PDUCaterpillarD t it Di l
RusselectricOnanA
LiebertPowerware
MGE
ATSUPS
System
Battery
ibution Bo
ard
Distribution
ution Bo
ard
STS
STS
STS
PDU
PDU
PDU
Detroit DieselCummins
Asco HiTecPiller
•••
Main Sw
itchb
oard
ATS UPS
Distri
on Boa
rd
Distribu
ribu
tion Bo
ard
STS
STS
STS
PDU
PDU
PDU
Gen . Controls
Cutler ‐HammerSiemens
GESquare‐D
IEM
ATS System
BatteryDistributio
Dist
stribu
tion Bo
ard
STS
STS
STS
STS
PDU
PDU
PDU
PDU
Gen . Controls
R l i Dis STS PDU
RAISED FLOOR (APPRX. 75% OF TOTAL FOOTPRINT)
RusselectricOnanAsco
Cutler ‐HammerSiemens
GESquare‐D
IEM Cutler ‐HammerSiemens
GEIEM
ExideGNB
C&D/JohnsonPowerHawker
ELECTRICAL ROOM
Power Distribution
Page 5 12/16/2010 2:16:29 PMPower Transmission
New Challenges Force ChangeNew Challenges Force Change
• Increasing power densitiesIncreasing power densities(typically 4‐6KW, now 12 up to 30, with possibilities of
70kW per rack)
• Improved cooling strategiesImproved cooling strategies • Need for scalability• Need for modularityy• Data centre consolidation• Server virtualization• Energy saving initiatives
Traditional Power DistributionTraditional Power Distribution
• Majority use under floor power• Majority use under floor power distribution
• Typically via cables fed from a distribution panel
• The panel is located on the raised floor in order to reduce voltagefloor in order to reduce voltage drop in smaller conductor
• The panel is normally fed by a secondary breaker typically located in a critical distribution panel or UPS output switch gearpanel or UPS output switch gear.
Traditional
One whip to each cabinet
PDUA
Distribution Panel
Under Floor Cable Power Distribution
C i d fl Congestion under floor – obstructs air flow
PDUB
Distribution PanelDistribution Panel
Problems with traditional power di t ib tidistribution
Inhibits flexibility : circuit additions yare difficult, requires new cable installation, location of new panel breakers, temporary removal of floor tiles, opening of deadfronts, wire pulling and circuit verificationwire pulling, and circuit verification.
Restricts airflow; obstructing under floor air currents, someunder floor air currents, some cables are abandoned in place
Not scalable
No modularity
CostlyCostly
Increased risk of human error
Emerging Trend toward overhead distributiondistribution
Over head Cabinet power distribution via an overhead track busway– Allows users to quickly insert or relocate plug‐in units and electrical power
drops. – Continuous open access and allow for power drops to be inserted instantly
anywhere along the buswayanywhere along the busway. – Modular, three‐phase systems which consist of electrified copper conductor
bars within lightweight housing. – Circuits are added or removed through a turn‐n‐lock insertion process which
allows users to insert and remove plug‐in units without shutting down power.– Eliminates the need for power distribution panel boards and multiple cables. – Include a circuit breaker in the plug in unit which improves protection and
id l l di tiprovides local disconnection means. – Possible to eliminated the raised floor, which significantly reduces data center
construction costs.
Comparison of DC distribution MethodspOH Conduit &
wireUF
cableOH cable
OH busway
OH bus track Comments
Requires raised floor N Y N N N Raised floor costs are highCircuit change w/o load Dependant on amount of
disruption N N N N Y infrastructure installed initiallySingle & three phase
available at load N N N Y Y Facilitates load diversityInstallation costs 4 2 3 1 1 1= lowest cost
Restricts cold air flow N Y N N N air flow dampeningRestricts cold air flow N Y N N N air flow dampeningRequires entry/exit
airflow MGMT N Y N N NBypass air can be created by cable entry/exit points
Load connection at any location Y Y Y N Y
Dependant on amount of infrastructure installed initially
Requires remote circuit identification Y N N Y Y Visual circuit management
Periodic re‐torqueing required N N N Y N
connection joints may require re‐torqueing
Circuit changes reducesCircuit changes reduces static pressure N Y N N N Removing floor tiles impacts cooling
Circuit protection close to load N N N Y Y
Protection is improved when close to load
Risk of standing water penetration N Y N N N
Fixed physical phase relationship N N N Y Y Reduces mis‐wires
Benefits of over head Track Busway• Flexibility: add/remove circuits in minutes
• Non‐disruptive to Power: add/remove circuits without d i i l d
Benefits of over head Track Busway
de‐energizing load
• Improves Energy Efficiency: overhead power improves cooling by removing underfloor cable air dams also reduces bypass airflow by eliminating cable access holesreduces bypass airflow by eliminating cable access holes (brushes, grommets' etc)
• Scalability: power connections can be added as needed deferring costs until cabinets require power
• Modularity: Varying power densities can be fed with the same busway infrastructure
• Easily Configurable: single or three phase loads from the bsame busway
• Low Cost: Generally lower material costs and significantly less labor than traditional methods
• Does not use valuable floor space by eliminating raised• Does not use valuable floor space by eliminating raised floor mounted PDU
Benefits of over head Track Busway• Expandable: higher densities can be easily
accommodated in the futureR d l bl b l t d t th• Re‐deployable: can be relocated to other applications with relative ease
• LEEDS recognized: gain Leed’s points because of it’s sustainability (reusable), adaptability (ease of change), scalability (expandable without modification), and energy efficiency (cooling waste reduction
Reduces risk of human error by improving visual circuit management
Improves reliability as electrical connectionsImproves reliability as electrical connections are made via mechanically reducing the risk of a mis‐wire.
Reduces chance of phase overloads because conductor physical location never changes
Plug in box design facilitates live plug in
Paddle(Plug Head)
l i d
Mounting Tab with Hanger Bolt
Polarized to prevent improper installation
Plug ‐ Guide
Breakers
Enclosure
Receptacles
Typical plug‐in box shown. Hundreds of configurations are available.
Inserting Plug In Into Access SlotInserting Plug‐In Into Access Slot
Plug Head inserted completely into busway
Plug Guide fits firmly around busway housing while enclosure is solidly against the enclosure is solidly against the plug guide.
Plug in unit enclosure is Plug in unit enclosure is bonded to aluminum housing
during insertion process protecting the installerp g
Rotating Plug‐In Into Access Slot
Rotate plug‐in such that the Rotate plug‐in such that the blades engage the busbars. Enclosure and Plug Guide firmly pressed up against busway. p p g y
Rotate plug‐in until it is parallel to the busway
NOTE: The typical circuit breaker/ NOTE: The typical circuit breaker/ receptacle faces the direction of the busbar side of busway (B225 & 100A)
Securing Plug‐In Into Access SlotSecuring Plug‐In Into Access Slot
Insert hanger bolt on the mounting tabthe mounting tab
Securely tighten hanger bolt to gmounting tab
About the Track Busway
Extruded Aluminum Housing 225A Version Shown
U‐Shaped busbars
Insulators that surround the busbars and provide a “finger p gsafe” product.
Continuous open bottom
About the Track Busway
Copper ConductorStab on Plug‐InStab on Plug In Paddle
• Constant “spring” tension created by the U‐Shaped busbarShaped busbar.
• Creates a maintenance‐free connection.
Typical Track Busway SystemSystem
E d C
Threaded Rod Housing Section
Coupler SetsEnd Cap
Hangerg
Tee
End Power Feed Elbow
Benefits of overhead power d bdistribution
Fl ibiliFlexibility
• Allows for technology refreshing
Flexibility to accommodate frequent change without service disruption is mandatory.
• With overhead flexible power distribution systems, circuits are easily added with very little risk to load. Overhead distribution can accommodate varying loads as the main infrastructure is designed to serve high and low density, single and th h l d f d I d d t fthree phase loads from day one. Independent of the type of server used, the systems basic infrastructure remains unchanged.
Benefits of overhead power d bdistributionReliability
• Reduces risk of human by improving visual circuit management which reduces the probability• Reduces risk of human by improving visual circuit management which reduces the probability of inadvertent operation of incorrect circuit breakers.
• Track busway electrical connections are made via mechanical connections thereby significantly reducing the risk of a mis‐wire.
• Track Busway also mechanically fixes the physical relationship between conductors, unlike cable where conductors can be in any physical relationship, thereby reducing the chance of improper phase connections.
B fit f h d di t ib tiScalabilitySince most centres will not initially run at full capacity they
Benefits of overhead power distribution
Since most centres will not initially run at full capacity, they must be designed with the ability to accommodate sustained growth without interruption of existing services.
Overhead power systems are designedOverhead power systems are designed to allow for expansion by simply adding on to the existing system or by installation of additionalor by installation of additional systems. When an additional row of servers is added, simply add another row of over head track busway. If a row is expanded, just add more track.
Benefits of overhead power d b
ModularityA modular approach provides a plan for overall capacity utilization in a
distributionA modular approach provides a plan for overall capacity utilization in a number of smaller units. Traditional power distribution methods do not lend themselves to modular
design concepts as the exact configuration of the load is requiredconfiguration of the load is required at day one. Overhead track busway systems use a basic infrastructure for all loads. Only the plug in unit is specifically configured for thespecifically configured for the particular load. The basic infrastructure can be added as modules are added and loads connected as they are determinedconnected as they are determined, without changing the track system.
Benefits of overhead power distributionBenefits of overhead power distributionEnergy Efficiency
• Removing the under floor cables and reducing under floor obstructions.
• Cable obstructions make the air distribution very non‐• Cable obstructions make the air distribution very non‐uniform, creating pressure differentials that can lead to data centre hot spots. High pressure exists upstream of cable, tow pressure downstream; creating large airflow through the upstream perforated tile and low airflow in the downstream perforated tile. Thus, a server rack placed in the downstream region can be starved of cooling air and may overheat. If you remove the cable obstructions, this non‐uniformity will go away.
• “Over head power also mitigates the single biggest offender in the waste of cooling efficiency which is improperly sized raised floor penetrations for cabling that allow bypass air. Although the use of proper airflow management, including seals, brushes, air dams and other accessories can help control bypass air; it becomes a non‐issue when power is delivered overhead. Under floor cabling also requires that the tiles be removed during circuit additions. This can significantly decrease static pressure during the time of circuit addition.
• In some cases, it is possible to gain Leed’s points with overhead track busway as it can be defined to meet the requirements of sustainability (reusable), adaptability (ease of change), scalability (expandable without modification) and energy efficiency (cooling waste reductionwithout modification), and energy efficiency (cooling waste reduction
• Overhead track busway also shares a common neutral which helps promote material efficiency while phase balancing increases energy efficiency.
ConclusionsConclusions• The final selection of either an under floor or an
overhead power distribution system is a balance between construction specifics, operational metrics, physical constraints, and the evolutional demands of the enterprise. That final selection will have to survive the ever changing shape of thehave to survive the ever changing shape of the environment IT supports. In the end, it can be said that there are reasons for installing both under floor and over head power systems in the data centre. Both have their own set of advantages and limitations which have to be taken into account while choosing either of them. Nevertheless, as a general trend under floor power distribution andgeneral trend, under floor power distribution and subsequently even raised floors are giving way, to overhead track busway power solutions along with a growing number of solid floor designs.