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• 15-25 percent reduction in

operating expenses

• 75 percent or higher asset

utilization

Even seemingly small power

infrastructure efficiency improvements

can add up to big savings. For

instance, with energy costs at

$0.10/kW, a 1 percent efficiency

improvement for a single 1 MW UPS

translates into approximately $10,000

in annual savings. For instance,

updating a legacy power system with

a new power distribution system can

improve its efficiency by about 2

percent for an annual energy savings

of $20,000, with a five year ROI.

Upgrading to a modern UPS system

will reduce losses at the UPS itself by

4-5 percent, yielding a $40,000-

$50,000 annual savings and also a

five year ROI.

In addition to cutting operating

expenses, modern power

infrastructures can improve

application availability, and they can

reduce the complexity and increase

the cost-effectiveness of future

growth. The strategies outlined below

will enable you to gain a more

efficient, productive and available

data center while managing capital

costs.

DEPLOY NEW TRANSFORMER-

FREE, DOUBLE CONVERSION

UPS TECHNOLOGIES

Legacy uninterruptible power supply

(UPS) systems for enterprise data

centers typically operated at a peak

efficiency of 91-92 percent at 100

percent load (85 percent efficiency at

40-60 percent load). The other 8-9

percentage points are lost as a

byproduct of the conversion process,

and this has traditionally been

accepted as a reasonable price to pay

for protection from unplanned

downtime. But with new high-

efficiency options, many modern UPS

technologies offer higher efficiency in

all modes of operation.

Today, transformer-free UPS systems

operated in double conversion mode

are 96-97 percent efficient at 100

percent load and 94-95 percent

efficient at 40-60 percent load.

Considering that only a 1 percent

efficiency improvement at $0.10/kWh

for a single 800kVA UPS translates

into approximately $10,000 in annual

savings, the reduction in operating

expenses can be significant when you

multiply this savings by the number of

UPS units in use.

Some UPS systems also offer an eco-

mode operation option that allows

the conversion process to be

bypassed, and operating efficiency

increased even further. This mode can

be enabled when data center

criticality is not as great or when

utility power is known to be of the

highest quality. This is accomplished

by utilizing the automatic static

bypass switch of the UPS during eco-

mode.

This bypass normally operates at very

high speeds to provide a break-free

load transfer to a utility or backup

system during maintenance and to

ensure uninterrupted power in the

event of severe overload or

instantaneous loss of bus voltage.

The transfer takes less than 4

milliseconds to prevent any

interruption that could shut down IT

equipment. With eco-mode and using

intelligent controls, the UPS can stay

on utility power as an efficiency mode

of operation, circumventing the

normal AC-DC-AC conversion

process while the UPS monitors

bypass power quality. If utility power

is out of specification, the UPS will

transfer back to double conversion

mode.

INVEST IN NEWER POWER

DISTRIBUTION UNIT (PDU)

TECHNOLOGY

The UPS system and PDUs are key

components in the data center power

infrastructure; the UPS feeds power

through the PDUs to IT equipment

throughout the facility. The three

functions of the PDU system have not

changed over the past decade:

1. Transform the voltage from 480V

or 600V to 208/120V so it can be

used by the IT equipment. Most

servers run on 208V line-to-line

today.

2. Distribute and control the power.

There is a circuit panel on the

secondary side of the PDU feeding

various servers located on the data

center floor. Many businesses

meter their circuits to measure the

amount of energy provided to

each server or set of servers.

Metering is especially helpful to

colocation providers to measure

customer energy use and,

depending on the rate structure,

bill for it.

3. Monitor energy consumption to

manage planning. Data center

managers can view and

understand energy consumption

from a central location via the PDU

system, allowing them to take

holistic actions to improve

efficiency.

At the PDU level, the efficiency of the

transformer technology has improved

and meets certain mandated

efficiency standards that are in place

today. The National Electrical

Manufacturers Association mandates

standard TP 1-2007 (NEMA TP 1-

2007), which specifies minimum

efficiency levels based on transformer

size. Generally, the specified

efficiencies are greater than 98.5

percent for the most common PDU

sizes used today. Before the TP 1-

2007 standard, PDU efficiency was

96-97 percent, so deploying newer

PDUs can add another two or more

efficiency points at the PDU itself.

ENABLE A HIGH-DENSITY

ENVIRONMENT

Dense environments are inherently

7X24 MAGAZINE SPRING 2015