Electrical Distribution System in a Data Center: Medium-voltage (MV) and Low-voltage (LV) switchgear

May 12th, 2020 07:06 AM

So far we explored the Electrical Distribution System in a Data Center. The critical supply from the utility / transformer / generator to the load is enabled by various types of power equipment. One of the key components of the critical supply is switchgear.


Medium-voltage (MV) Switchgear

Medium-voltage switchgear is generally located in the power substation of large-capacity data centers (i.e. greater than 1 MW IT load). This equipment is typically fed directly from the utility and usually marks the utility service entrance to the building.

If a MV generator is present, it also feeds the MV switchgear. The following figure shows an example of MV switchgear single line diagram:-

10kV MV Switchgear Single Line Diagram

Other than simply distributing power, the MV switchgear is responsible for disconnecting faults and controlling the MV power distribution system, for example, when isolating a redundant section for maintenance.

Basically medium-voltage switchgear is the assembly of four cubicles as shown in the Figure above: two incoming units (incomers) or main section, outgoing units or feeder section, voltage metering unit, and bus section or tie section/breaker.

The outgoing unit distributes three-phase power to the primary (upstream) side of the MV / LV transformer. Due to safety distances at MV, typically each cubical is limited to only one MV circuit breaker.


The following are some typical electrical parameters for MV switchgear. Values for these parameters vary according to local regulations:


Voltage ratings:-

Two key voltage ratings for MV switchgear are rated voltage and rated lightning impulse voltage (equivalent to the ANSI basic impulse level i.e. BIL). For example, an ANSI MV switchgear solution may have a rated voltage of 15kV and 95kV BIL (i.e. impulse voltage).


Current ratings:-

The rated current of MV switchgear is always specified by the manufacturer. Another key current rating is the rated short-circuit withstand current similar to the North American National Electric Code’s (NEC) short-circuit current rating (SCCR).

For example, an ANSI MV switchgear solution may have a rated current of 1200A and 40kA SCCR.



Low-voltage (LV) Switchgear

Typically LV switchgear / switchboard is located in the electrical room and marks the utility service entrance for data centers less than 1 MW.

An example of LV switchgear is shown in figures below. If a LV generator is used, the generator would feed the LV switchgear. Apart from distributing power, the LV switchgear is responsible for disconnecting faults and controlling the LV power distribution system.

Note that in the case of a medium voltage generator, this transferring function occurs at the medium voltage switchgear level.

In real situation, the single line diagram will look something like this:-

A device known as an Automatic Transfer Switch (ATS) has traditionally been used to switch between utility and generator. However, the current trend is to have LV breakers perform this function in lieu of the ATS device. Also, there is a practice of using PLC logic for switching between utility and generator sources.

The following devices are always assembled in LV switchgear: horizontal busbar, vertical busbar, circuit breakers, meters, switches, surge arresters, relays, etc.

LV switchgear / switchboard installed in a data center is typically a combination of some of the following functional units: incoming feeder from the secondary side of the MV / LV transformer or LV generators, power control center (PCC, i.e. for downstream UPS), motor control center (MCC, i.e. for pumps), the power factor correction/harmonic filtering and the bus connections.


The following are key electrical parameters of the LV switchgear. The values for these parameters vary according to local regulations:


Voltage ratings:-

Two key voltage ratings for LV switchgear are rated voltage and rated lightning impulse voltage. ANSI does not specify the impulse voltage for LV switchgear. For example, an IEC LV switchboard solution may have a rated voltage of 690V and 12kV rated impulse withstand voltage.


Current ratings:-

The rated current of LV switchgear is always specified by the manufacturer. Another key current rating is the rated short-circuit withstand current similar to the North American National Electric Code’s (NEC) short-circuit current rating (SCCR).

For example, an IEC switchgear solution may have a rated current of 5000A and 85kA rated short-circuit withstand current.

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.

(19th Round) Preparatory Course to Become a Registered Specialist Contractor (Ventilation Works) - RSC(V)

April 30th, 2020 07:52 AM

Further to our data center & critical facilities design courses, the team is going to deliver a preparatory course which helps engineers / enterprises to facilitate compliance with the Buildings Ordinance and to become Registered Specialist Contractors (RSC) in Ventilation Works in Hong Kong.

Last update on 30 April 2020

About SMA

Strategic Media Asia (SMA), a critical infrastructure training and event organizer, provides an interactive environment and opportunities for members of engineers to exchange professional views and experience on critical infrastructure and electrical and mechanical facilities.

In addition, SMA is one of the CPD Course Providers of the Chartered Institution of Building Services Engineers (CIBSE).

For other data center design and critical facilities courses, please visit our website at http://www.stmedia-asia.com/trainings.html.

  

註冊專門承建商（通風系統工程類別）預備課程 - 加強版

課程簡介

專門為通風及冷氣工程公司的關鍵人士：技術董事 (TD) 、獲授權簽署人 (AS) 或其他高級人員 (OO) 而設計，旨在幫助公司順利申請成為註冊專門承建商（通風系統工程類別）。

學員將會在短時間內熟習面試要點、建築物條例、通風及消防法例、職業安全健康與環保、通風及冷氣的專門 知識，並達至通風及冷氣工程師的專業水準。

關鍵人士的最低資格和經驗規定 〈 第 1、2 或 3 項 〉，可參考屋宇署網頁 《 註冊承建商作業備考 38 》- 附錄 F 〈註：現時已不接受 4 或 5 項的資格及經驗。〉

修讀條件

對相關註冊及考核事宜有興趣者均可參加。

第一部份 - 基本課程大綱 ( 約 8 小時 ) :

- 一般建築承建商和專門承建商的註冊事宜

- 註冊承建商作業備考 (PNRC)

- 通告函件

- 香港法例第 123 章建築物條例

- 香港法例第 123J 章建築物（通風系統）規例

- 香港法例第 132CE 章附表所列處所通風設施規例

- 香港法例第 95 章消防條例

- 防火閘、過濾器及聚塵器實務

- 通風 / 空氣調節控制系統實務

- 年檢證書

- 職業安全健康與環保

- 面試技巧


第二部份 - 進階課程大綱 ( 約 4 小時 ) :

- 申請食肆牌照通風設施規定
- 通風(空氣調節)系統標準發牌條件
- 申請符合通風系統規定通知書
- 暫准普通食肆牌照的衞生設施規定
- 正式普通食肆牌照標準發牌條件
- 符合規定證明書 D
- 工廠及工業經營(安全管理)規例
- 空調設備工程的工作安全及健康指引

課程資料

日期 (基本課程)：2020 年 9 月 5 日 及  12 日 ( 星期六 ) - 共 8 小時
日期 (進階課程)：2020 年 9 月 19 日 ( 星期六 ) - 共 4 小時

時間：9:00 - 13:00

地點：香港浸會大學持續教育學院 - 香港九龍彌敦道 136 號 A 
( 尖沙咀 地鐵站 B1 出口 / 佐敦 地鐵站 D 出口 )

授課語言：粵語 (輔以 中 / 英文講義)

報名表格：按此下載 或瀏覽課程網頁 (http://www.stmedia-asia.com/aircon.html)

了解其他 關鍵設施專業課程

主講導師

Ir Edmund Fok

BEng(Hons), MSc, PFM, REA, RSO, CEnv, CEng, FCIBSE, FSOE, FIPlantE, MHKIE

擁有二十多年豐富冷氣通風、消防、水務、電力及建築工程經驗及十多年教學經驗，並是註冊專門 承建商 (通風系統工程) 獲授權簽署人、第 1 , 2 & 3 級註冊消防裝置承辦商合資格人士、一級水喉匠、註冊電業工程人員 (級別: C0 H0)、註冊小型工程承建商獲授權簽署人和註冊能源效益評核員。 

主辦機構

Strategic Media Asia Limited (SMA)

由多位經驗豐富的英國註冊工程師組成，榮獲 英國屋宇裝備工程師學會 (CIBSE) 認可，提供持續專業發展短期課程 / 進修時數 (Approved CPD Course Provider)，定期舉辦不同程度的關鍵設施課程、專業研討會及論壇，旨在提供合適的交流機會予機電工程師、屋宇裝備工程師、通訊及資訊科技界專業人士等等，同時提供關鍵設施及數據中心設計技術及知識。

詳情可瀏覽  www.stmedia-asia.com 。

Electrical Distribution System in a Data Center

March 12th, 2020 08:19 AM

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.

Never Stop Learning - Get your Training Manuals for Critical Facilities and Data Center Design

February 10th, 2020 03:27 AM

Reliability and Redundancy Matter - Your data center / critical facilities should be kept rolling under any circumstances. Understanding the infrastructure's design and operations can minimize disruptions and avoid costly downtime.

With our high quality training courses and credential programs, you are able to gain the knowledge and best practices in data center / critical infrastructure design, operations and efficiency:

   

Budget concern? Inconvenient to travel and take the face-to-face courses? Why don't consider to purchase the self-learning kit / training manuals which are currently on sale for further learning and reference?

Each manual is edited by a team of Chartered Engineers (CEng) who has more than 20 years experience in data center design & build, building services engineering, facilities management and energy conservation in the private and public sectors. All content has been fully taken into account the requirements of international codes and standards, which prepare you to face most of the challenges in data centers and critical facilities of any size, in any location.


For order details, please contact our team (www.stmedia-asia.com/contact.html) or visit the Amazon online. Payment can be made by bank wire or credit card. Worldwide shipping will be provided.

    

    

  

  

  

Part Time Vancancies for Local Engineers in Critical Infrastructure (Maintenance)

January 17th, 2020 11:38 PM

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





One of the leading data center owners in Hong Kong is looking for 2 - 3 part time engineers for the general maintenance of critical facilities in their data centers (ranged from Tier 3 to Tier 4-Ready) in Hong Kong. The critical facilities include

(1) CRAC Systems, Cooling Towers; 
(2) UPS, PDUs, Switchgear, Transformers and other Critical Supply Systems.


Those who interest in the opportunity and completed any one of our critical facilities courses:-

- Data Center / Critical Facilities Design & Infrastructure Engineering (2-day)
- Air Conditioning System Design for Critical Infrastructure / Data Center (2-day)
- Electrical Design for Mission Critical Supply (2-day)
- Project Management for Critical Facilities: From Design to Commissioning (2-day)


with relevant experience in data center environment / critical infrastructure are welcome to apply. Remittance will be based on work hours (in hourly rate). For details, please send your CV and salary expectation to info @ stmedia-asia.com. Only engineers with HKID card / working permit in Hong Kong will be entitled and referred. Thank you.



    
    
     

WDD World Data Resource Development Competition: Data Tech 2019 Hong Kong

December 10th, 2019 06:31 AM

The World Data Resource Development Competition (WDD) - Data Tech 2019 Hong Kong was completed on 5 December 2019 at the Hong Kong Convention and Exhibition Centre.

There are around 14 teams demonstrate their innovative business solutions integrated with the industry-driven application models through data mining / big data technologies. Through the competition, it connects businesses, technologies and talents in various industries, assists enterprises to hire big data talents and releases innovative and entrepreneurial power of different universities.

For details, please visit http://wdd.datarda.com/

Strategic Media Asia (SMA) -
Connecting IT, Facilities and Design
The team forms strategic partnership with the IOT HK Association and the Shenzhen Big Data Industry Association (International Hong Kong Branch).

Further to data center infrastructure, critical facilities and building services engineering, SMA expands the service portfolio and becomes a knowledge hub in Big Data, Internet of Things (IoT), Blockchain Technologies & Artificial Intelligence (AI).

Technical Visit for a Tier IV-Ready Data Center in Tseung Kwan O, Hong Kong

October 31st, 2019 10:53 PM

Learn MVAC / Air Conditioning System Design for Mission Critical Purposes

September 24th, 2019 07:19 AM

"One Belt, One Road and Bay Area" plus "Block Chain and IoT Application" Forums are Successfully Launched in Shenzhen

September 24th, 2019 07:18 AM

 

 

For details, please visit (https://mp.weixin.qq.com/s/sjIPn9RcqX2dWINE9akPnw)




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

The team forms strategic partnership with the IOT HK Association and the Shenzhen Big Data Industry Association (International Hong Kong Branch).

Further to data center infrastructure, critical facilities and building services engineering, SMA expands the service portfolio and becomes a knowledge hub in Big Data, Internet of Things (IoT), Blockchain Technologies & Artificial Intelligence (AI).

How to Choose Data Center Racks / Cabinets

August 9th, 2019 06:29 AM

With the rise of colocation, enterprise and edge data centers, the requirements for data center racks have changed from being a cabinet that manages equipment to a rack enclosure that can reduce data center operational costs by preserving valuable floor space, optimizing cooling and increasing the efficiency of IT staff.

There are 6 considerations before choosing a data center rack:-


1) Weight Loads

Today's organizations need data center cabinets that can hold heavier loads and maintain their structural integrity when shipped with equipment. This could mean shipping from their facility directly to a data center, or shipping from an off-site integrator directly to their data center. Shipping a fully-populated rack allows for a faster data center build-out. The raised floor and the maximum floor loading should be considered as well.


2) Open Framed or Closed Frame

Open frame racks typically cost about one third as its equivalent counterpart in a closed frame option. There is nothing to obstruct airflow from circulating through the rack for cooling. But all your equipment is exposed making it susceptible to theft. Your servers' buttons or wires may also accidentally get pulled or pushed.

 

On the other hand, the process of installing or maintaining equipment is trickier for the closed fram racks due to the obstructed nature. If you choose to use this type of rack, sliding rails and shelves for severs and other equipment is highly recommended.

3) Sizing and Capacity

Server racks are sized in units classified as "U" space. Each U represents 1.75". So, a server rack that is 58U is 101.5" tall. The rack height is significant for how much equipment that can be held inside, as well as how much power can be transmitted to equipment in the server storage device. Some organizations may require more space between the server rack and the ceiling for cooling and cabling matters.

Your data center business grows fast. Leaving racks' space for few years later is a good planning for data center expansion.


4) Off-site Integration Processes

Racks should provide the flexibility to accommodate equipment from multiple vendors in a company’s supply chain, and the equipment needs of its data center environment. Many standard cabinets make it difficult to meet these needs, and many companies are turning to custom cabinets to increase overall flexibility and maximize efficiency in their off-site integration process.


5) Multi-vendor IT Environments

Racks need to provide maximum usable space, adequate clearances for airflow, easy access for troubleshooting and reconfiguration of equipment by IT staff and minimize air mixing.


6) The Rising Cost of Cooling

Cooling can be one of the top costs in today’s data center and reducing cooling costs, which can begin at the rack level, can play a major role in reducing overall energy consumption. More powerful equipment and greater data center densities have increased the heat generated in each rack, causing computer room air conditioning (CRAC) units to work harder than ever.

For example, the closed frame racks isolate heat sensitive equipment inside the frame. You have more control over where that air flows with the addition of fans and cooling accessories designed for closed frame racks. Therefore, it is critical to have a rack that supports optimized cooling efficiencies.



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 center 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 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.