Electrical Distribution System in a Data Center

There are many different loads in the data center, such as IT devices, air conditioners (CRAC Units), pumps, lighting, etc. The critical supply from the utility / transformer / generator to the load is enabled by various types of power equipment. We are going to illustrate these equipment that are critical and without which it would not be possible to operate the data center.

Figure 1 is a block diagram of an electrical distribution system showing the name and the typical location of the electrical distribution equipment in a data center and the power flow path (Uptime Institute Tier Level II, N+1 Design) . This diagram is only an example of an electrical architecture and attempts to include all the possible major types of equipment used and their typical location in a data center. In the real world, a typical data center electrical design has much more complexity and diversity than that in this diagram.

Uptime Institute Tier II, N+1 Design

Figure 1 

Uptime Institute Tier III Design

Uptime Institute Tier IV, 2N+1 Design

Tracing the flow of power along its path (starting from the utility to the IT load) in the figure 1 above. It shows 8 essential facilities are critical for the power supply. This facilities distribute power to the downstream loads and also protect the power distribution system in the data center:

• Medium-voltage switchgear
• MV/LV transformer
• Low-voltage switchgear / switchboard / automatic transfer switch (ATS)
• UPS system with input/output switchboard and UPS distribution switchboard
• Power distribution Units (PDUs) and remote power panels (RPPs)
• Busway
• Panelboard
• Rack PDUs (rPDUs) / outlet strips

All facilities above, except for rack PDUs (rPDUs), are considered to be assemblies containing circuit breakers, switches, various types of relays, buses and connections, and control and auxiliary devices. Each device is optimized for long life and ease of maintenance.

The IEC 61947 & IEC 62271, which specifies the HV and LV switchgear terminology, considers switchboard to be the same as switchgear. For some regions like, North American, switchgear and switchboard are specified differently by ANSI and UL standards.

About Us


SMA combines with professional Chartered Engineers (CEng) from the Institute of Engineering Technology (IET), the Chartered Institute of Building Services Engineers (CIBSE) and the Hong Kong Institution of Engineers (HKIE). Our engineers have more than 20 years experience in data center design & build, building services engineering and energy conservation in the private and public sectors.

The team prepares the engineers and IT personnel to face any challenges in data centers and critical facilities of any size, in any location. For other design considerations / topics in data center and critical infrastructure, please visit 


(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards,
(10) Transformers and Harmonic Distortion,
(11) Multi-mode UPS Systems,
(12) Electrical Rooms,
(13) Generator Systems,
(14) Generator Fuel Systems,
(15) Battery Systems,
(16) Earthing / Grounding and Bonding, etc.

Learn MVAC / Air Conditioning System Design for Mission Critical Purposes

Air-Conditioning System Design for Critical Infrastructure (2-day)
4 -5 December 2019 - Approved CPD Course by CIBSE UK


This is a 2-day course for engineers who design or handle MVAC (Mechanical Ventilation and Air-Conditioning) equipment for mission-critical buildings / data center projects.

It highlights design principles such as psychrometric chart, cooling load calculation / estimation, etc. and the design considerations such as air distribution, availability / redundancy, common mistakes, Computer Fluid Dynamic (CFD) model, integration with MEPs (Mechanical, Electrical and Plumbing systems), etc.

You'll be able to make informed decisions about the best choices of cooling systems for mission-critical purposes and how system can best meet your project goal and SLA (Service Level Agreement).


Date: 4 - 5 December 2019 (Wednesday - Thursday)
Time: 09:00 - 17:30
Venue: 19/F, Officeplus (New Victory House),
93 - 103 Wing Lok Street, Sheung Wan, HK (Exit A2, Sheung Wan Station)


Fee: Special Rate applies for

(1) the HKIE / CIBSE or all professional membership classes in engineering; or
(2) more than 1 enrollment made at the same time


> Datacom Equipment Power Trends and Cooling Applications

-- Load trends and their application
-- Air cooling of computer equipment
-- Liquid cooling of computer equipment


> Design Consideration

-- Design criteria
-- HVAC load
-- Computer room cooling
-- Air distribution
-- Liquid cooling
-- Availability and redundancy
-- Controls
-- Integration with other MEP (Mechanical, Electrical and Plumbing) system
-- Computer Fluid Dynamics (CFD)


> Testing and Commissioning

-- Air cleanliness test
-- Heat load test
-- Factory acceptance test
-- Site acceptance test
-- Integrated performance test (IST)


> Energy Efficiency

-- Power usage effectiveness
-- Chilled water plant optimization
-- Water side and air side equipment
-- Part load operation
-- Controls and energy management
-- LEED certified data center
-- Building energy code


> Sustainable Design

-- Combined heat power plant (CHP)
-- Solar cooling
-- Geothermal cooling
-- Evaporative cooling
-- Air side economizers
-- Desiccant unit


For details, please visit www.stmedia-asia.com/newsletter_6.html.


Enrollment & Registration

Kindly complete and return an Application Form for seat reservation. Online Registration is also acceptable. Your seat will be confirmed once the payment is allocated. Thank you.
 

About the Organizer

Strategic Media Asia Limited (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The mission is to provide an interactive environment and opportunities for the members of critical facilities industry and building services engineers to exchange professional views and experience.

For details, please visit www.stmedia-asia.com/about.html.




Subscribe to our Knowledge Blog in Critical Infrastructure Design

RELIABILITY & REDUNDANCY MATTER - Your facilities and IT infrastructure are complex that are different from general buildings and require special design and operation knowledge and skill. Understanding the design considerations and avoiding costly downtime are critical.
Subscribe to our Knowledge Blog (http://green-data.blogspot.com or http://data-center-design.tumblr.com), share your view and get monthly readings online. All topics focus on key components and considerations of designing / operating mission-critical facilities and infrastructure:-

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards,
(10) Transformers and Harmonic Distortion,
(11) Multi-mode UPS Systems,
(12) Electrical Rooms,
(13) Generator Systems,
(14) Generator Fuel Systems, 
(15) Battery Systems, etc. 

P.S. Think your team might also be interested? Pass it on ›


Strategic Media Asia Limited
Connecting IT, Facilities and Design

T (852) 2117 3893  |  F (852) 2184 9978
Room 403, 4th Floor, Dominion Centre, 43 - 59 Queen's Road East, Hong Kong

http://www.stmedia-asia.com  |  http://green-data.blogspot.com 

2-day Classroom Training in Critical Facilities Design + Data Center Technical Visit

A BIG THANK YOU to the fellow participants who attended our 2-day instructor-led training course in Data Centre Facilities Design and Infrastructure Engineering during 29 - 30 November 2018. The course details about data center infrastructure system that supports critical services and prepares individual to understand the main components that facilitate the whole system’s design & build, international standards and best practices.

  

Following the 2-day classroom training in critical facilities design, our Data Center Technical Visit was completed on 7 December 2018. The visit provided an interactive environment for the data center / infrastructure engineers to exchange professional views and experience on mission critical facilities and IT services involved.

  

 

  

Strategic Media Asia (SMA) -
Connecting IT, Facilities and Design

SMA combines with professional Chartered Engineers (CEng) from the Institute of Engineering Technology (IET), the Chartered Institute of Building Services Engineers (CIBSE) and the Hong Kong Institution of Engineers (HKIE). Our engineers have more than 20 years experience in data centre design & build, building services engineering and energy conservation in the private and public sectors.

The team exists to provide an interactive environment and opportunities for members of data center and facilities' engineers to exchange professional views and experience, through various training courses, industry events and technical seminars. We prepare the engineers and IT personnel to face any challenges in data centers and criitcal facilities of any size, in any location.

For details, please visit www.stmedia-asia.com.

Designing Generator Fuel Systems (4)

Referring to the Designing Generator Fuel Systems (1), (2) and (3), let's summarize to form a whole picture.

The successful design of a backup generation system is critical to maintaining business continuity, sustaining critical operations, and life safety in the event of a serious power outage (see "Fuel system design checklist"). Without proper design and ongoing maintenance, fuel oil systems cannot meet the needs of the gensets they serve, and therefore, cannot guarantee the assumed reliability of the facility's backup power.


Fuel System Design Checklist
When designing fuel oil systems, remember

• Provide foot valves (to maintain pump prime), anti-siphon valves (to prevent accidental leakage), and fusible link shutoff valves (for fire safety).
• When calculating pump suction lift, assume the worst-case scenario (i.e., a nearly empty tank).
• When calculating friction losses through the fuel oil distribution system, assume the worst-case scenario (i.e., viscosity corresponding to the lowest anticipated fuel temperature).
• If fuel temperature is anticipated to fall below its cloud point, provide a means of heating (tank heaters, space heaters, pipe heat trace, etc.)
• Ensure storage tanks are equipped with adequate ports to accommodate pipe connections, sensors, vents, switches, etc.
• Using auxiliary tanks if necessary

Consider Using Auxiliary Tanks When

• The main tanks are located more than 50 ft away from the gensets
• The main tanks are located more than 12 ft below the gensets
• The main tanks are located above the gensets

Fuel Oil Design Cheat Sheet

Refer to this cheat sheet for important considerations when designing a fuel oil system:

• No. 2 fuel oil NFPA Classification: Class II
• Genset fuel consumption: approximately 7 gph/100 kW rating
• Atmospheric pressure: 30 in. Hg (mercury column)
• Minimum recommended pressure at external pump inlet: 15 in. wc
• Pressure of 2.6 ft of No. 2 fuel oil: 1 psi.

Runtime Requirements

Runtime requirement for emergency power supply systems, according to NFPA 110: Standard for Emergency and Standby Power Systems include:


Class 0.083: 0.083 hours = 5 minutes
Class 0.25: 0.25 hours = 15 minutes
Class 2: 2 hours
Class 6: 6 hours
Class 48: 48 hours
Class X: other times (application, code, or user dictated)



About us

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The team exists to provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For the other design considerations, please visit 

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards,
(10) Transformers and Harmonic Distortion,
(11) Multi-mode UPS Systems,

(12) Electrical Rooms,

(13) Generator Systems,
(14) Generator Fuel Systems, etc.

All topics focus on key components and provide technical advice and recommendations for designing a data center and critical facilities.

Designing Generator Fuel Systems (3)

So far we consider (1) Runtime Criteria; (2) Storage; (3) Pumping; (4) Fuel Cooling; (5) Piping; and (6) Fuel Maintenance of the generator fuel system. Let's further look into the

(7) Fuel Filling
(8) System Controls
(9) Applicable Codes and Standards


Filling the Tank


During the design process, it is important to determine what type of delivery truck the fuel-oil vendor will use. Fuel-oil trucks are either a gravity or a pump type (i.e., equipped with an integral fill pump).

Both types of trucks can accommodate USTs and ASTs located at an elevation lower than the truck. Pump trucks are ideal for filling ASTs at higher elevations. Gravity trucks are optimal for filling USTs. However, when the fuel storage tank is at a higher elevation than the truck, a gravity type truck alone won't work. For such applications, an option is a remote fill system with an integral fuel transfer pump that can enable gravity trucks to fill ASTs at a higher elevation. Remote fill systems are equipped with gauges and sensors to aid and alert the operator during the delivery process.

Extreme considerations must be accounted for as well because the need for fuel oil could happen in an emergency state. For example, it is common for a fuel oil vendor to promise one type of truck, but then in the event of a city-wide power outage when everyone needs fuel, the truck isn't available. Extreme situations must be considered during fuel oil system design.


Fuel System Controls


Fuel systems typically use UL 508: Standard for Industrial Control Equipment - listed programmable logic controllers (PLCs) to control and monitor transfer pumps, storage tanks, auxiliary tanks, polishing systems, fill systems, fuel inventory, leak detection, and other related subsystems and equipment. They offer communication capabilities, such as BACnet, Modbus, and local operating networks (LonWorks) for integration with the building management system.

For critical applications, such as data centers, the control system typically uses dual independent PLCs and dual power inputs to ensure there are no single points of failure. The fuel system control architecture and sequence of operations should be reviewed in detail during the design phase. The entire scope of work associated with fuel systems (equipment, controls, startup, and training) preferably should be provided by a single vendor who specializes in that field.


Codes and Standards


Due to its combustible nature and the detrimental impact on the environment upon a leakage, fuel oil storage and system design is regulated by city, state, and federal authorities. Careful consideration to a multitude of factors is essential during design. Meeting the worst-case scenario is vital to compliance.

There also are code-mandated requirements related to maximum allowable fuel storage on the property, tank construction, spill containment, location relative to buildings and property lines, fire suppression, high-rise building limitations, and much more. The requirements are specifically stringent for applications involving indoor storage of fuel due to inherent fire hazards. Frequently, the requirements listed in various codes and standards differ significantly.


To avoid surprises at a later stage, it is beneficial to approach the authority having jurisdiction to review the proposed design early in the project - specifically with representatives from the fire department to ensure that all bases are covered.


Continue Reading: Designing Generator Fuel Systems (4)



About us

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The team exists to provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For the other design considerations, please visit 

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards,
(10) Transformers and Harmonic Distortion,
(11) Multi-mode UPS Systems,

(12) Electrical Rooms,

(13) Generator Systems,
(14) Generator Fuel Systems, etc.

All topics focus on key components and provide technical advice and recommendations for designing a data center and critical facilities.

Designing Generator Fuel Systems (2)

Per "Designing Generator Fuel Systems (1)", we have discussed (1) Runtime Criteria; and (2) Fuel Storage. We are going to consider:-


Fuel Oil Pumping


Gensets are equipped with gear-driven pumps that pressurize fuel in the common rail of the engine. The integral pump draws fuel from the external tank. Excess fuel not injected into the cylinders is returned back to the tank. The pump has limited capability for priming and overcoming friction losses in the fuel distribution system (piping, fittings, and filters).

Usually, two types of electric-driven fuel oil pumps are used external to the genset - gear pumps and centrifugal submersible pumps:

Gear pumps: Mounted on a separate skid and typically used for low-flow, high-pressure applications, these pumps can be internal or external gear type and suitable when pressure requirements exceed 40 psi.

Submersible pumps: Used for high-flow, low-pressure applications. It require adequate clearance above the fuel tank for accessibility and maintenance, even though the majority of the pump assembly is within the tank.

Static lift and friction losses should be reviewed in detail during fuel system design. The design flow rate of the pumping system should be two to four times the peak demand so that pumps operate intermittently to fill the auxiliary tanks instead of operating continuously.


Cooling the Fuel


Excess fuel in the common rail that isn't injected into the cylinders is sent back to the tank. The return fuel is at an elevated temperature because it absorbs heat from the injectors and water jacket. When it mixes with cooler fuel in the tank, the supply fuel temperature gradually starts to rise.

For every 12 degree Celsius rise in fuel temperature above 37 degree Celsius, the engine horsepower reduces by approximately 1%. High fuel temperature also reduces its ability to lubricate the engine fuel system components. If the temperature of fuel being supplied to the engine exceeds a certain limit (typically 60 - 65 degree Celsius), the genset shuts down because of the safety cutoff. This is especially problematic when the tank volume is relatively small (e.g., auxiliary tanks) and the return fuel temperature is not reduced.

This basic fuel oil system flow schematic reveals the main fuel storage and auxiliary tanks.


Gensets with unit-mounted radiators typically are equipped with fuel coolers. They take advantage of the engine-driven radiator fan to reject fuel heat. Gensets with remote radiators typically require an external fuel cooler to reject fuel heat. Another option is to provide a return pump at the auxiliary tank and exchange fuel with the main tank (return hot fuel and replace it with cold fuel) if fuel temperature exceeds a certain setpoint. The return pumps also can be enabled manually to empty the auxiliary tank for maintenance, or via level sensor to prevent overflow conditions.


Fuel Transfer Pipes


When designing underground site piping, a nonmetallic material, such as reinforced thermosetting resin pipe is preferred due to its inherent corrosion protection. Underground piping is almost universally double-wall, and is comprised of a carrier pipe and a containment pipe. The interstitial space between the pipes is monitored with a leak detection system.

Fuel transfer pipes located above ground in accessible areas typically are single-wall carbon steel. Note that local jurisdictions and insurance carriers may require double-wall piping for aboveground applications as well.


Fuel Oil Maintenance


Fuel oil is made up of organic compounds and will gradually degrade over time due to biological growth, water accumulation, and particulate formation. This degradation, if uncontrolled, could result in clogged filters, or could negatively impact the combustion process in the generator engine.

Degradation is not a concern for applications where fuel is used on a consistent basis and a fresh stock of fuel is introduced regularly—for example, gensets used for combined heat and power applications. For standby generator applications, fuel usage is minimal due to limited runtimes as a result of periodic testing. For such applications, a fuel maintenance or polishing system can be provided for treating fuel oil periodically (usually on weekly or biweekly basis).


Continue Reading: Designing Generator Fuel Systems (3)



About us

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The team exists to provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For the other design considerations, please visit 

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards,
(10) Transformers and Harmonic Distortion,
(11) Multi-mode UPS Systems,

(12) Electrical Rooms,

(13) Generator Systems,
(14) Generator Fuel Systems, etc.

All topics focus on key components and provide technical advice and recommendations for designing a data center and critical facilities.

Designing Generator Fuel Systems (1)

Backup generator sets (gensets) are critical to business continuity and life safety. To ensure their reliable and efficient operation, the design of the associated fuel system must be approached systematically and thoroughly.

There are 9 Key Considerations when designing fuel oil systems for gensets:-

(1) Runtime Criteria
(2) Fuel Storage
(3) Fuel Pumping
(4) Fuel Cooling
(5) Fuel Piping
(6) Fuel Maintenance
(7) Fuel Filling
(8) System Controls
(9) Applicable Codes and Standards

Understanding the requirements and challenges of each is critical to navigating the design of any fuel system. Note that although there are inherent nuances, some of the same considerations underlying fuel oil design principles can also be applied to systems intended for other applications, such as oil-fired boilers. Design criteria unique to each project will dictate the ultimate application.


Runtime Criteria


Among the first steps of designing a fuel oil system for gensets is to establish runtime criteria in the event of a power outage (see "Runtime requirements"). Often dictated by a combination of applicable codes and owner requirements, the runtime—or how long the genset must operate during an emergency event without refueling-will set the bar for fuel oil design and operations. For example, life safety gensets typically are required to support emergency loads for a period of 2 hours upon loss of power. Critical facilities, such as data centers, typically are expected to support the load for 24 hours or more, depending on site resiliency requirements.

Because runtime criteria have a direct bearing on the fuel storage capacity required onsite, this consideration is critical to explore first. Note that fuel consumption data for gensets at various loads is readily available from the manufacturers.

It is important to note that only 80% to 85% of the tank capacity is typically usable depending on the tank shape and form. The tank cannot be emptied completely during operation nor can it be filled completely because head space is required to accommodate fuel expansion and prevent overflow.


Fuel Oil Storage


Fuel oil can be stored in aboveground storage tanks (ASTs) or underground storage tanks (USTs). Each has advantages and disadvantages, and specifying the appropriate type is critical to ensure the optimum design. Both UST and AST have different internation codes specifies the requirements for protected tanks (fire, impact and and associated corrosion resistant).

ASTs offer ease of maintenance; typically, lower installation costs and the ability to be installed by the project's mechanical contractor; ease of relocation; and the option of custom sizes to suit site conditions. However, employing an AST may not be appropriate for all projects because they require usable real estate, pose a greater fire hazard, allowable storage capacity typically is restricted by applicable codes and insurance carriers, and fuel heaters may be required in cold weather applications where the tank is exposed to subfreezing ambient temperatures.

USTs are available in fiberglass or steel construction. They are almost always cylindrical and require minimal real estate above ground, offer potentially greater fuel storage capacity, pose a lower fire hazard, and can maintain a relatively stable fuel temperature. Conversely, USTs can be difficult to access, maintain, and relocate; they typically have a higher installation cost; require comprehensive leak detection systems; and often require a specialized contractor to install.


Continue Reading: Designing Generator Fuel Systems (2)



About us

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The team exists to provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For the other design considerations, please visit 

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards,
(10) Transformers and Harmonic Distortion,
(11) Multi-mode UPS Systems,

(12) Electrical Rooms,

(13) Generator Systems,
(14) Generator Fuel Systems, etc.

All topics focus on key components and provide technical advice and recommendations for designing a data center and critical facilities.

Data Center Design Consideration: Meet Me Rooms (MMR)

A co-location facility / carrier-neutral data center hosts services from multiple carriers (telecommunication companies) or organizations. Meet-me rooms (MMR) are important physical spaces (2 or more for redundancy) located in the building of a co-location data center or carrier-neutral data center. Data center clients use this space to interconnect or cross-connect to a single or multiple carriers (for redundancy) and to exchange information, which can be transmitted to individual computers via the Internet, without incurring local-loop fees.

Although the concept and practice of using an MMR are not new, the initial creation and management of these spaces over time has become a serious challenge for operators. Owing to some poor practices and lack of building standards, there have been occasions where new clients' preferred carrier could not be accommodated as a result of physical / location challenges. We are going to outline some design best practices.



CABINETS AND SPACE


A carrier generally asks for at least 2 four-post, 84" (45U) high cabinets in each MMR. If the operator is providing only AC power, the carrier may request additional rack space for rectifiers and batteries, should they be using DC equipment.

The best practice is to meet with the intended carriers all at once to create a rack and space solution that they can all agree on. Although this may be a difficult task to schedule, it will be worthwhile to reach an agreement on one typical rack type and one layout look and feel.

Clients who inspect your facilities before signing a contract will appreciate a consistent look to this space. Permitting odd-size cabinets combined with open-frame racks of all colors and widths will detract from a professional look and limit the usefulness of space for new or different functions.

Meet-Me Rooms tend to be smaller because fibers would be run from a user suite to patch panels in an MMR to be interconnected, which requires little space. With time, these rooms have grown in size and are starting to resemble data centers, including features such as cages.



LOCATION


The location of the MMRs would be outside the computer rooms, in the secure data center space. When determining location for one or redundant rooms, consider the industry standards for distance, which will vary according to service type and media (fiber/copper/coax). Placing the MMR on an outside wall is ideal if the space will double as the point of entry so that equipment and workers can go in and out using external doors without disrupting data hall's operations.

Depending on the expected user population, locating the MMR on an exterior wall and even near a loading dock could be a deal breaker for security reasons. If your clients require significantly more security than normal commercial businesses, the MMR should not act a main point of entry but should instead be placed within the data center, away from external walls.



CONNECTIONS


The connection to the data center clients and carriers / MMRs have many methods. Some standards exist. Each method has challenges in co-location facilities, and each challenge can be met so long as they are identified early and planned for.


Direct Connect —

Each carrier connects directly with the client from the carrier-equipment rack to the client-side demarcation point or equipment rack which is also located in a secure half of the MMR (see figure below). The client then extends to the floor space.

The MMR is split for security reasons between clients and carriers. Clients are permitted in their side of the MMR, and carriers in theirs. This approach could increase the amount of conduit in the ceiling space and limit future installations.

Using a private cage for client-side equipment or third-party cross-connect provider as the only staff permitted in the client side of the MMR could limit a security concern.

Direct Connect (Extended Demarcation Point) —

It means each carrier connects directly with the client from the carrier-equipment rack in the MMR to the client-side demarcation point located in the client space (see figure below). Multiple conduits demanded by clients can quickly fill any available space above the ceiling.

Cross Connect in the MMR —

Each client space has pre-installed patch panels located in a secure side of the MMR whereby multiple carriers cross-connect (see figure below). The pre-installed facility is then patched to the client's equipment in the floor space.

Similar to the "Direct Connect" method, some clients may express security concerns with this topology and carriers may not like the potential that a competitor could accidentally unplug their patch. If the MMR is professionally managed (which is highly recommended), the carrier would not have access to this side of the MMR.





Cross Connect in Client's Floor Space —

Patch panels are placed in each carrier’s secure equipment rack and pre-connected to each client's space (see figure below). Drawbacks include higher upfront costs to carriers and operators, who may never connect to every client, and loss of operator cross-connect fees.

MANAGING  MMR


Try to create in-building standards and include them in every lease agreement. In addition, carrier agreements should include adherence to your standards. These standards need to outline access-control, cross-connect, interconnect, and direct-connection means and methods, as well as installation and pathway standards, cable count and color standards, and labeling criteria.

Access Control —

Control access to carrier sides and, if designed, client sides of the MMRs. Only permit third-party MMR management companies to have access to both rooms. Make sure this access is authorized, authenticated and audited. Ensure the design disables any opportunity for a carrier or tenant to literally “throw a cable over the wall” to make a connection.


Connection Methods —

A good cable installer can be assigned to the task of managing the MMR as long as the standards are well documented and SLAs between that company and the operator exist.


Pathway Standards —

The MMR space above the ceiling is not limitless; as such, controls must be put in place to ensure large (and typically unused) conduits are not positioned between data connection points. Traditional cable tray is a sure means of transporting media; most clients will claim that cable trays are an inherent security risk, however. The use of flexible armored cable is something all operators should consider. It is lightweight, able to bend and ultra-thin compared with conduit.


Color Codes —

Color coding the media is a best practice for many reasons. Colors can designate fiber-types, counts, installation dates and specific client connections. Mining out the infrastructure of past clients is easy once the cables are identified, and identification by color is a quick means of disposal.



For details of the MMR and structured cabling system design (copper and fiber cables), please consider to attend a credential program and further learning for telecommunications spaces, horizontal and backbone distribution systems.



About SMA

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK.

The team exists provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For accreditation details and background, please visit www.stmedia-asia.com/about.html.

2-day Training in Project Management for Data Center & Critical Facilities: From Design to Commissioning

2-day Advanced Training in Project Management for Data Center & Critical Facilities: From Design to Commissioning

(19 - 20 October 2017, 2-day)


Building, upgrading or relocating new data centers / mission-critical facilities requires extensive coordination. Project management team shall ensure all components come together smoothly. It is typically fast track from design and planning to testing and commissioning.

You are cordially invited to attend the course which highlights key components required by a project management team who directs the manufacturing, the outfitting and the preparation for a data center / computer room while simultaneously oversees site work, infrastructure for facility, utility installation, etc. and facilitate IT installations.


It also details about how to structure the project management activities with a common language (for data center and mission-critical purposes), avoid cost increment, responsibility gaps and duplication of effort and achieve an efficient process with a predictable outcome. Most importantly, the course outlines how to meet the project goal and SLA (Service Level Agreement) before, during and after completion of the project defined by the owner.


- Reviewing the Project Management Basics

> Planning and Programming a Successful Project for Mission-critical Purposes
> Managing a Project on Time, Cost and Quality

- Contract Management for Data Center Design and Build
- Roles and Responsibilities
- Liaising with Clients (Facility Owners, Project Owners, etc.)
- Liaising with Stakeholders
- Liaising with Design Consultants / Architect
- Managing Facilities / Services Suppliers
- Managing Contractors
- Assessing the Project Progression and Status Meetings
- Conflicts Management
- Change Management and Accommodation
- Project Handover, Testing and Commissioning
- Cases Study


Date: 19 - 20 October 2017 (Thursday - Friday)
Time: 10:00 – 17:30 (around 13 hours)
Venue: Ground Floor, Innocentre, 72 Tat Chee Avenue, Kowloon Tong, Hong Kong

Fee: Special rate for CIBSE / HKIE all membership classes


For details, please refer to www.stmedia-asia.com/newsletter_6.html.

About us

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The team exits to provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For the Data Center Design Consideration, please visit 

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection,
(8) Raised Floor,
(9) Code & Standards, and
(10) Transformers and Harmonic Distortion


All topics focus on key components and provide technical advice and recommendations for designing a data center and critical facilities.

A Data Center Nightmare: Single Point of Failure (3)

Refer to "A Data Center Nightmare: Single Point of Failure (1) and (2)"


The two examples (1) and (2) mentioned emphasize the importance of several lessons that might seem like common knowledge, but slipped past all parties in the complex design and construction process of the data center.


(I) It is very important to eliminate single points of failure. Had there been dual paths to the critical load and either static switch power-distribution units or rack-mounted static switches, there would have been no data center failure.

(II) It is essential to use conduit and wire instead of busduct. Every electrical connection is a potential failure. The feeder busway system installed had mechanical connectors every 12 feet. Conduit and wire only have connectors at the source and at the load.

(III) Only equipment for mission-critical purpose are allowed in data centers! The installed busway was inherently unreliable because human error led to one failed connection and the two additional failed connections uncovered during testing.

Unfortunately, data center professionals do not necessarily have the chance to test drive a facility before it’s completely operational. At the end of the day, every data center is a unique. Professionals must take all of the right steps to make sure they anticipate future mishaps and learn the lessons of previous experiences.


Five Elements of a Reliable Data Center

Building and designing a data center is a complicated process. The complexity is compounded not only by the building type, but by the fact that each data center is unique, built and designed to meet specific criteria. A successful project depends upon five things:

• Good design with input from the facility executive, builder, designer and commissioning agent
• Good construction, including careful selection of construction firms and subcontractors, as well as effective construction administration and documentation of field issues
• Specification and installation of quality data-center-grade materials
• Effective commissioning
• Thoughtful operational practices and timely maintenance

About the Blog

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The team exists to provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For Data Center Design Consideration, please visit 

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection, and
(8) Raised Floor

All topics focus on key components and provide technical advice and recommendations for designing a data center and critical facilities.

A Data Center Nightmare: Single Point of Failure (2)

Refer to "A Data Center Nightmare: Single Point of Failure (1)"


Data center failures can be rooted in several sources - design, construction, maintenance, quality of material, quality of equipment, commissioning and direct human intervention. For the most part, data centers, even ones that fail, have the benefits of good design practice and intention, professional construction oversight, and high-quality craftsmanship. They are maintained according to data center quality guidelines. But a single overlooked mistake can quickly become significant issues - power and air conditioning failure - that can bring down a data center.

Another story is a high-profile government data center, with a busduct-panelboard connection exploded, effectively shutting off power to approximately 15,000 square feet of the most critical computing in the facility.

In this incident, the design relied on an isolated redundant uninterruptible power supply (UPS) back-up. When a UPS system failed, a static automatic transfer switch was to shift to the already-operating isolated redundant UPS and transfer the load within a quarter cycle. The system worked well and the client was satisfied with the transfer scheme and the rotary concept.


Source of the Problem


Where this system failed was downstream from the automatic transfer switch. Each of the switches fed one busduct riser and terminated directly into a main distribution panel located on each floor of the facility - one busduct per panel. A single fault on any busduct or main distribution panel compromised the critical load.

As it occurred, the electrical connection between the busduct and the distribution panelboard failed and the load was lost. A single point of failure succeeded in bringing down the floor. Not until the facility’s electricians ran jumper cables from one of the intact risers and back-fed the main distribution panel did the floor have power.

Why did this failure occur? The building had been designed in tight coordination between the government representative and the designer; the entire system had been commissioned and had been running with tight oversight for more than two years. What happened?

The cause of the problem was the failure of a manufactured busduct connector, one of hundreds in the building. The connector joined lengths of feeder busduct via a sliding piece - designed to slide approximately one-quarter of an inch to make installation easier - and a break-away torque bolt designed to ensure that the installer did not over-torque the bolt.

Although the investigation team was not asked to explain exactly why the joint exploded, it determined that the quarter-inch of play designed into the connector had actually allowed for a portion of uninsulated section of the copper busduct to be exposed to the atmosphere without insulation. The team surmised that the perfect combination of air borne dust, humidity and possibly other contaminants led to an arc that became a fault and exploded.

During the analysis, the investigation team isolated each busduct riser from the static automatic transfer switch at the source and from the main distribution panel at the termination. During the megger test, the electrical forensic team discovered two additional joints that didn’t pass, clearly more candidates for potential failure. Not only did the joints not pass the megger test, two of them visibly and audibly arced while the voltage was ramped up during the testing. The joints had shown themselves to be the weak link in the system. The installed busduct technology was vulnerable to catastrophic failure.



Continue - A Data Center Nightmare: Single Point of Failure (3)

About the Blog

Strategic Media Asia (SMA) is one of the approved CPD course providers of the Chartered Institution of Building Services Engineers (CIBSE) UK. The team exists to provide an interactive environment and opportunities for members of ICT industry and facilities' engineers to exchange professional views and experience.

SMA connects IT, Facilities and Design. For Data Center Design Consideration, please visit 

(1) Site Selection,
(2) Space Planning,
(3) Cooling,
(4) Redundancy,
(5) Fire Suppression,
(6) Meet Me Rooms,
(7) UPS Selection, and
(8) Raised Floor

All topics focus on key components and provide technical advice and recommendations for designing a data center and critical facilities.