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Chloride Solutions for Data Centers Application

Abstract

Recently, the number of critical mission applications has increased. Data Center one of

these applications. It is vital to keep supplying computer equipment of the data center,

because the momentary failure of a single 20 Amp circuit breaker can result in hours of

information disruption to end users and can easily cost millions of dollars in

unrecoverable revenue. To achieve high availability to your power system The Uptime

Institute defines four tiers configuration to help designer of data center to choose the

correct one. It is important to consider the power factor capability in choosing the UPS,

where you need wide range between 0.8 lagging to 0.8 leading (sometimes 0.9). Chloride

is the only UPS manufacturer who has this feature as standard including high size UPS.

Chloride offers complete solution for data centers including different tiers configuration,

service centers around the world, availability of spare parts, trained engineers and Life

Net (maintenance support software).

What is Data Center?

A data center is a facility used for housing a large amount of electronic equipment,

typically computers and communications equipment. As the name implies, a data center

is usually maintained by an organization for the purpose of handling the data necessary

for its operations. A bank for example may have a data center, where all its customers'

account information is maintained and transactions involving these data are carried out.

Practically every company that is mid-sized or larger has some kind of data center with

the larger companies often having dozens of data centers. Most large cities have many

purpose-built data center buildings in secure locations close to telecommunications

services.

As data is a crucial aspect of most organizational operations, organizations tend to be

very protective of their data. A data center must therefore keep high standards for

assuring the integrity and functionality of its hosted computer environment. This is

depicted in its physical and logical layout.

Physical layout of Data Center

A data center can occupy one room of a building, one or more floors, or an entire

building. Most of the equipment is often in the form of servers racked up into 19 inch

rack cabinets, which are usually placed in single rows forming corridors between them,

see figure 1. Servers differ greatly in size from 1U servers to huge storage silos which

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occupy many tiles on the floor. This allows people access to the front and rear of each

cabinet. Some equipment such as mainframe computers and storage devices are often as

big as the racks themselves, and are placed alongside them.

A "U" is defined by the Electronics Industry Association (EIA) as a height unit

measuring 1.75 inches, or 4.45 centimeters, of vertical space within a rack.

Figure 1- Multiple racks of servers, and how a datacenter commonly looks

Challenges for Data Center

As companies move towards consolidating data center space and reducing operating

costs, more IT professionals are considering including blade servers within their selection

of new server deployments. Blade servers have been touted as an important new

infrastructure element for the "flexible" enterprise data center. Capable of turning the

hype of "on-demand" or "utility" computing into reality, blade servers are considered

highly modular devices that offer three to ten times the density of traditional, rack-

mounted servers, along with substantial improvements in management cost and systems

integration costs. However, as blade servers have begun to penetrate the market, list of

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concerns have arisen such as issues related to power and cooling systems. IT

professionals must not only weigh the costs and benefits of implementing blade servers,

but also conduct scrupulous planning and design in order to optimize the use of blades

within the enterprise data center.

Backup power for data center is supplied by one or more uninterruptible power supplies

and diesel generators. To overcome power supply challenge The Uptime Institute

developed a four tiered classification approach to site infrastructure functionality with

different levels of availability.

Tier I: Basic Site Infrastructure

Tier I has non-redundant capacity components and single non-redundant distribution

path to serve the site’s computer equipment. As a result, any failure in capacity

component or distribution path will impact the computer systems, in addition to that,

planned work will require most or all of the systems to be shut down, impacting the

computer systems.

GEN

N

Utility Sw. Gear

Mech. Sw Gear U

P

S

N

Mech. System

UPS OUTPUT

Sw Gear

P

D

U

COMPUTOR

Transformer

Figure 2- Electrical System Tier I

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Tier II: Redundant Capacity Components Site Infrastructure

Tier II has redundant capacity components and single non-redundant distribution paths

serving the site’s computer equipment. So, a capacity component failure may impact the

computer equipment, but distribution path failure means computer equipment down.

GEN

N

Utility Sw Gear

Mech Sw Gear U

P

S

N

Mech System

UPS OUTPUT

Sw Gear

P

D

U

COMPUTOR

Gen Sw Gear

GEN

+1

U

P

S

1

Transformer

Figure 3- Electrical System Tier II

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Tier III: Concurrently Maintainable Site Infrastructure

Tier III has redundant capacity components and multiple distribution paths serving the

site’s computer equipment. Generally, only one distribution path serves the computer

equipment at any time. This give the possibility for each and every capacity component

and element of the distribution paths can be removed from service on a planned basis

without causing any of the computer equipment to be shutdown. In order to have

concurrent maintainability of the critical power distribution system between the UPS and

the computer equipment, Tier III sites require all computer hardware have dual power

inputs as defined by the Institute’s Fault Tolerant Power Compliance Specification

Version 2.

GEN

N

Utility Sw Gear

Mech Sw Gear

U

P

S

N

Mech System

UPS OUTPUT

Sw Gear

P

D

U

COMPUTOR

Gen Sw Gear

GEN

+1

U

P

S

1

Critical MCC Critical MCC

Critical Fan

or Pump

Utility Sw Gear

Transformer

Transformer

Mech System

ALT OUTPUT

Sw Gear

P

D

U

Figure 4- Electrical System Tier III

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Tier IV: Fault Tolerant Site Infrastructure

Tier IV has redundant capacity systems and multiple distribution paths simultaneously

serving the site’s computer equipment. So, all IT equipment is dual powered and installed

properly to be compatible with the topology of the site’s architecture.

GEN

N

Utility Sw Gear

Mech Sw Gear

U

P

S

N

Mech System

UPS OUTPUT

Sw Gear

P

D

U

COMPUTOR

Gen Sw Gear

GEN

+1

U

P

S

1

Critical MCC Critical MCC

Critical Fan

or Pump

Utility Sw Gear

Transformer

Transformer

Mech System

UPS OUTPUT

Sw Gear

P

D

U

Gen Sw Gear

GEN

+1

GEN

N

U

P

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1

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Figure 5- Electrical System Tier IV

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Table 1- Comparison Between different Tiers

Tier I Tier II Tier III Tier IV

Ultimate W/m² 215-320 430-540 1100-1650 >1700

Single point of

failure

Many + Human

error

Many + Human

error

Some + Human

error

None + fire and

EPO

Annual site

caused IT

down (field

data)

28.8 h 22.0 h 1.6 h 0.8 h

Site

availability

99.67 % 99.75% 99.98% 99.99%

Typical

months to

implement

3 3-6 15-20 15-20

Chloride Solutions for different Tiers

Chloride can deliver the four different tiers starting from single UPS to complex parallel

systems. In the mid range there are different choices of UPS solutions both transformer

and transformer-less design UPS:

• 70-NET [10 – 60kVA]: Transformer-less UPS design, Intelligent Double

Conversion topology.

• 80-NET [60 - 200kVA]: A double IGBT converters UPS transformer-less

design, Intelligent Double Conversion topology.

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• 90-NET [60 – 800kVA] : Transformer design UPS, Intelligent Double

Conversion topology ,12P rectifier with low THDi UPS with the lowest

footprint.

Figure 6 - 500 KVA UPS

Large range UPS solution has one of the smallest footprint on the market thanks to the

careful project engineered, which means reduce the total cost of the Data Center i.e by

reducing the area it leads to make total cost (Dollars per square foot cost evaluation

model) of data center less. For example, 500 KVA UPS has been built using only one

cabinet with dimensions (mm): 1780 Height X 2020 Width X 858 Depth.

Power Factor Compatibility

Another challenge in power supply is the wide power factor (from 0.7 lagging to 0.9

leading) required by data center due to the mix of older and newer server technologies.

Key advantage for UPS and CROSS is to be optimized for any PF behavior (lagging or

leading) without any de-rating (i.e. must have a symmetrical power output diagram figure

7). Chloride UPS 90-NET, 80-NET, 70-NET and Linear Plus can handle loads

irrespective to the output PF behavior (with different limits for the maximum output

active power in kW) and CROSS is the only STS range in the market that can work with

any PF load. Higher power factor can be achieved by limiting the recharging battery

current. As can be seen from figure 8 below, 90-Net can work with 0.9 PF without de-

rating, while 80-Net can work with 1 PF without de-rating. In brief, Chloride is the only

one to offer this capability as standard feature also in the very high power range.

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Chloride has different types of parallel system (up to 8 units in parallel):

1- Modular Parallel: As can be seen from modular parallel system block diagram,

each UPS has rectifier, battery, inverter and internal static switch. In modular

parallel system both UPS’s are supplying the load and share it 50% per each UPS

(thanks for vector control technology which Chloride use to control their UPS). In

case of one UPS failure, the second UPS will continue supplying the load without

interruption, which means higher availability for your site infrastructure.

Uper limit 80-NET

Figure 7 - symmetrical power output diagram

Nominal 70-NET,

90-NET and 80-

NET

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MODULAR PARALLEL SYSTEM

TO THE

LOAD

MAINS

INPUT

UPS A

BYPASS

INPUT

UPS A

OUTPUT UPS A

AC/DC DC/AC

C.S

UPS A

BYPASS

MAINS

INPUT

UPS B

OUTPUT UPS B

BYPASS

INPUT

UPS B

AC/DC DC/AC

C.S

UPS B

BYPASS

2- Centralized Parallel system: In centralized system internal static switch is

removed from the UPS and located externally in Common Output Cubicle (COC).

Again both UPS’s are redundant and sharing the load.

CENTRALISED PARALLEL SYSTEM

TO THE LOAD

MAINS

INPUT

UPS A AC/DC DC/AC

OUTPUT

UPS A

UPS A

SYSTEM

BYPASS

INPUTC.S

C.O.C.

BYPASS

MAINS

INPUT

UPS B AC/DC DC/AC

OUTPUT

UPS BUPS B

3- High Fault Clearance parallel system (valid for 90-Net): It shall be possible to

allow simultaneous operation of both the UPS (up to 8 units) reserve lines (within

each UPS) and the external reserve line in external cabinet (COC). Transfer to

reserve will therefore involve the parallel operation of all the available reserve

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lines (both UPS and external reserve). As a result of such a paralleling of reserve

static switches, the overall I2t capacity of the system shall be multiplied by four.

The increased short circuit capacity of this parallel mode of operation will result

in increased ability to clear faults downstream from the UPS and hence greater

overall selectivity. This parallel configuration shall only be feasible if all reserve

lines originate from the same distribution. All modules within this system (UPS

and External reserve) will share the load equally (provided that the installation is

balanced respect to the current distribution).

AC/DC DC/AC

S.S

UPS B

BYPASS

AC/DC DC/AC

S.S

UPS A

BYPASS

S.S.C.O.C.

BYPASS

MAIN INPUT

UPS B

RESERVE

INPUT

UPS B

MAIN INPUT

UPS A

RESERVE

INPUT

UPS A

SYSTEM

RESERVE

INPUT

HIGH FAULT CLEARANCE

H.F.C. CONFIGURATION

LOAD ON RESERVE OPERATION

Chloride has capability to have 8 units are connected in parallel, which means in case of

underestimate the power requirements (nowadays 150 W per square foot) or future

unplanned load expansion, you can easily add more UPS to the existing one and increase

your power capacity.

Chloride Solution for Tier IV

As we have seen from The Uptime Institute classification for Tier 4, the computer

equipment needs two input sources and two independent distribution paths. To achieve

that we will use Static Transfer Switch (CROSS).

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The static switches (CROSS) will be designed and made in compliance with the

following (Figure 8):

Each static switch will consist of a pair of thyristors (SCRs) connected in anti-parallel

and inserted on each phase;

An input load switch with auxiliary indicator contact;

A line bypass load switch with auxiliary indicator contact.

CROSS will have an output switch with auxiliary indicator contact.

CROSS ratings: 16A, 32A and 63 A for single phase (CROSS rack), 160A, 250A, 400A,

600A, 800A 1250A three phases CROSS.

Example of Tier 4:

Let us consider system layout in figure 9, it is cleared that there are two independent

parallel systems ( A & B), synchronization box to make sure both systems are always

synchronized with each other and CROSS to supply the computer equipment in the data

center. In normal mode your computer equipment is supplied either by UPSA or UPSB

(you can select the priority from CROSS main panel). Suppose you have problem /

failure on UPS A, CROSS will detect this fault and transfer ALL equipment were

supplied by UPS A to UPS B and ensure safe and secure operation for computer

equipment.

Figure 8 - CROSS

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Another factor has to be considered is the UPS maintainability. Chloride has service

offices world wide (Chloride office or through our business partner), where you can find

trained service engineers and required spare parts close to customers site ready to help

our valued customers. Chloride developed a unique service tool, where you can monitor

your system 24 hours per day, 7 days per week and 365 days per year, which is Life Net.

Customer can receive sms text message on his mobile from Life Net about UPS system

status. In addition to that, customer receives monthly report about his system, battery

status, input mains quality, output load…etc.

The physical environment of the data center is usually under strict control:

• Air conditioning is used to keep the room cool, it may also used for humidity

control. Generally, temperature is kept around 20-22 degrees Celsius (about 68-72

degrees Fahrenheit). The primary goal of data center air conditioning systems is

to keep the server components at the board level within the manufacturer's

specified temperature/humidity range. This is crucial since electronic equipment

in a confined space generates much excess heat, and tends to malfunction if not

adequately cooled. Air conditioning systems also help keep humidity within

acceptable parameters. The humidity parameters are kept between 35% and 65 %

Relative Humidity. Too much humidity and water may begin to condense on

internal components; too little and static electricity may damage components. To

reduce heat rejection from UPS, Chloride produces UPS with high efficiency. For

example, 90-Net efficiency is 92-93% in double conversion mode and 97% in eco

mode.

• To help customer monitor the data center ambient temperature, Chloride offers

environmental sensor ( monitor both temperature and humidity), which connected

BUS B

BUS A

UPS

A

UPS

B

Figure 9 – Chloride’s Solution for Tier 4

Synchronization

Box

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to UPS (up to 16 sensors) and customer can monitor the status of UPS as well as

temperature and humidity of data center room from his desk using Chloride

monitoring software.

• Data centers often have elaborate fire prevention and fire extinguishing systems.

Modern data centers tend to have two kinds of fire alarm systems; a first system

designed to spot the slightest sign of particles being given off by hot components,

so a potential fire can be investigated and extinguished locally before it takes hold

(sometimes, just by turning smoldering equipment off), and a second system

designed to take full-scale action if the fire takes hold. Fire prevention and

detection systems are also typically zoned, and high-quality fire-doors and other

physical fire-breaks used, so that even if a fire does break out it can be contained

and extinguished within a small part of the facility. Chloride offers Emergency

Power Off contact, which can be connected to fire system protection control

system and make complete shutdown UPS in case of fire.

Figure 10 – Environmental sensor