# Data Center: Know the Difference Between Three-Phase & Single-Phase Power

Posted on August 6, 2017 by Gento  |  Comment (1)

Throughout North America, homes are powered by 120-volt single-phase electricity. A typical residential circuit breaker box reveals four wires coming into our homes: two “hot” wires, a neutral wire and ground. The two "hot" wires carry 240 VAC, which is used for heavy appliances like electric ranges and dryers. However, the voltage between both hot wire and the neutral wire is 120 VAC, which powers everything else in our homes. However, electricity generating manufacturing plants in North America transmit three-phase power at super high voltages ranging between 230 kV and 500 kV. A close look at high tension power lines reveals three separate conductors, each of which carries current, plus a neutral conductor. Three-phase power is less costly to distribute because transmission lines for three-phase power don't need the same heavy gauge copper wires as a single-phase transmission line would need. Further, three-phase offers flexibility at the service connection and can give customers not only the customary 120 VAC service but also 208 VAC. Virtually every industrial building, including yours, receives three-phase power, as it offers many advantages over single-phase.

Designing or retrofitting a data center to use three-phase power pays off, but some centers do not understand the benefits three- phase power brings. Let's take a look at the differences between single and three-phase power to understand why three-phase power not only delivers real cost savings but creates a more efficient data center.

The Problem with Single-Phase

Conventional 120 VAC single-phase service running at 60 Hz cannot deliver continuous power. At that frequency, the alternating current sine wave crosses the zero point 120 times each second. It’s best to understand that power is measured in Watts, and Watts is the product of Voltage applied times Amperes of current flowing in a circuit (W=V x A).

When either voltage or current crosses the zero point, the electrical power being delivered falls to zero. In practice, those instantaneous drops to zero don't visibly affect equipment in the circuit. If the equipment is a motor, for instance, the mechanical inertia of its spinning armature “rides through” the zero points. (However, those zero point crossings do add up. Motors running on single-phase power have shorter life expectancies than those designed for three-phase power). Similarly, if the equipment under load is solid state electronics, smoothing capacitors in the power supply filter “buffers” those zero points.

Three-phase power, on the other hand, consists of three sine waves separated by 120 degrees. This form of power is created by an AC generator with three independent windings, each exactly 120 degrees apart. Each current (phase) is carried on a separate conductor. Due to the phase relationship, neither voltage nor current flow applied to an IT load ever drops to zero. This means three-phase power at a given voltage can deliver more power. In fact, about 1.7 times the power of a single-phase supply.

In recent years the processing power that can be configured in a single rack has multiplied. Not too long ago a rack might have held as many as ten servers that consumed 5 kW. Now, due to never-ending miniaturization and the unstoppable march of technology, that same rack might hold four or five dozen servers—and consume more than 15 kW.

Powering a 15 kW rack with single-phase power at 120 VAC draws 125 Amps. The copper needed to safely carry that current, AWG 4, is nearly a quarter-inch in diameter. [1] It's hard to work with and expensive. Clearly, single-phase isn't practical for such loads. However, in a three-phase system, each conductor, AWG 11 at just 0.09-inch diameter, would only carry about 42 Amps. If interested in drilling down more into the arithmetic behind this read our blog “3-phase, 208V Power Strips (Rack PDUs) Demystified, Part II: Understanding Capacity”.

How Three-Phase Can Help

Your choice of a power system can bring you efficiency and economy, or inflexibility and excessive costs. Single-phase power is ideal for residential users whose biggest load comes from a dryer or electric range. Data centers, though, need to look at the benefits three-phase power brings. These include:

• Can run both 120 VAC and 208 VAC devices from the same power source, mixing and matching PDUs as required.
• Three-phase allows you to run all your devices on 120 VAC today, but upgrade to 208 VAC simply by swapping out your PDUs—which you can do quickly and without significant downtime.
• The cost of cabling falls dramatically when you deliver three-phase power directly to your server cabinets.
• The work required of electricians installing AC cabling, and total installation time, are both reduced.

If you're already using Raritan products, you'll find support at our online help center. However, if you're looking for ways to future-proof your data center using three-phase power, contact us to learn how our PDUs fit into the mix of solutions you will need.

{/exp:comment:form} --}

# What Are the Top Concerns for Data Center Managers?

Posted on May 22, 2018 by Gento  |  Comments (4)

Top Four Concerns for Data Center Managers
Preparedness is often the first step for resolving potential challenges and devising solutions. As such, in order to properly prepare for the future of data centers, it is important to first understand the top concerns for data center managers.

1. Climate Change. -- In a recent 2018 study, more than 50 percent of participating organizations were concerned about the potential for climate change disruptions to existing data centers. Throughout the globe, organizations need to take into consideration the potentially negative impacts of rising temperatures, growing floodplains, and an increase in violent storms. All three types of climate change coincide with the increase in region-wide disasters. In order to prepare for this potential challenge, data centers need to include disaster and emergency planning efforts into the broader business continuity plans for the entire organization.

2. Data Center Infrastructure Security Threats. -- Due to the nature of the sensitive business and personal information that they hold, data centers need to remain vigilant for potential infrastructure security threats. Recent studies show that these attacks are more frequently being conducted on an IP-basis. As such, organizations need to effectively control how machines are connected to their data centers. Through private networks, a limited number of access points, and stringent monitoring systems, data centers can remain prepared to effectively combat infrastructure security threats.

3. Emerging Edge Computing Capacity. -- Edge computing is set to be one of the emerging technologies that disrupt the data center sector. This type of technology is a direct response for the need to process data closer to where it is generated, consumed, integrated, and computed. As with any emerging data center technology, the concern for many managers lies in security and data sovereignty. However, as organizations require access to data at the "edge," these solutions will continue to be implemented for a variety of purposes. From "store and forward," to data consolidation and backup, self-contained micro-modular data centers will play a key role in deploying a viable solution for edge computing.

4. DCIM Strategies. -- Data center complexity is on the rise. As a response to this increased complexity, the requirements for control, management, and visibility from DCIM software has also grown. Fortunately, DCIM products have recently matured to now offer rich, scalable, and stable management solutions to increase the forecasting, agility, and efficiencies of data centers. While it is still an under-deployed technology, it is expected that as it continues to mature, so too will it become a more widely adopted solution. The challenge for data center managers will be creating and implementing the operational changes needed to support DCIM software.

The Bottom Line: Be Prepared for Upcoming Challenges
Climate change, data center infrastructure security threats, edge computing, and DCIM strategies are all concerning areas for data center managers. As these emerging technologies continue to be adopted, data centers will need to take a proactive approach. Through a state of preparedness, data centers can more readily adopt the technologies needed to meet the growing needs of organizations. Finally, with the right knowledge and preparation, data centers can continue to grow and evolve as they adopt new technologies, address the concerns of data center managers, and meet the evolving needs of organizations.

Posted on May 17, 2018 by Gento  |  Comments (4)

With the rapid expansion of data centers creating highly complex IT infrastructures, it’s becoming more important than ever to find ways to increase the efficiency of day-to day operations.  One of the most practical ways to achieve improved efficiency is through devices that are easy to use and easy to deploy.

# Cost Savings with Micro Data Centers

Posted on May 4, 2018 by Gento  |  Comments (2)

Major changes in data centers operations have historically involved the location of data processing. At one time, this function was moved off-site to mainframes, but the advent of microcomputers, now known as desktops or PCs, brought data processing back to the customer’s own data center. Cloud servers and collocated data centers resulted in data processing being performed off-site once again.

Today, some organizations are using micro data centers to process data on their own premises. This solution can provide performance improvements that justify the initial expense of a data center and has the potential to gain wide acceptance in the near future.

# 5 Reasons to Prioritize Rack-Level Management Now

Posted on April 25, 2018 by Gento  |  Comments (17)

If you’re an IT leader, you’ve probably made significant investments in data center management over the past few years. That’s because the success of the organization you serve depends heavily on the technical and economic performance of your data center. So the more digital your organization becomes, the smarter you have to be about how you manage your data center infrastructure.

Chances are, though, that you’ve focused on aggregate management of your data center as a whole. That’s good – but it will only get you so far. To fully optimize the value your business derives from its data center capex and opex, you must aggressively pursue operational excellence at the rack level.

# What is an intelligent PDU?

Posted on April 25, 2018 by Gento  |  Comments (16)

An Intelligent Power Distribution Unit (iPDU) is a networked power distribution unit that increases the efficiencies of data centers with real-time remote power monitoring, environmental monitoring, and data center infrastructure integration. Intelligent rack PDUs deliver technologies which enables a smarter IT infrastructure so you can stay ahead of problems before they occur. They help achieve the ultimate goal of any data center manager, maintaining uptime while reducing cost.

Page 1 of 42 pages  1 2 3 >  Last ›

#### Other Blog Posts

What Are the Top Concerns for Data Center Managers?
Posted on May 22, 2018
Posted on May 17, 2018
Cost Savings with Micro Data Centers
Posted on May 4, 2018
5 Reasons to Prioritize Rack-Level Management Now
Posted on April 25, 2018
What is an intelligent PDU?
Posted on April 25, 2018

View all Blog Posts

#### 近期活动

Cisco Live 2018
March 6-9, 2018  •  Melbourne, Australia
DataCloud Asia 2018
March 22, 2018  •  Singapore
DCD Indonesia
Apr 5, 2018  •  Jakarta
Data Centre World Hong Kong
May 16 – 17, 2018  •  Hong Kong
CDCC China
May, June, July, Nov 2018  •  Wuhan, Hangzhou, Chengdu, Beijing

View all Events

#### 力登最新新闻

Legrand Makes 451 Research’s List of Largest Data Center Technology Suppliers
Posted on May 4, 2018
Finding Weak Links in Your Security Policy and How to Safeguard Data Centers Will Be Addressed by Raritan Speaker at AFCOM Conference
Posted on March 8, 2018
Raritan Introduces Secure Switch for KVM Access to Government and Military Computers
Posted on March 6, 2018
Ashley Fox of Raritan Inc. Recognized as 2018 CRN Channel Chief
Posted on February 27, 2018
Packet, Myriad Supply, Raritan, and Data Center Knowledge to Participate in ‘Managing the Edge’ Webinar
Posted on November 12, 2017

View all news