10 Things You Need to Know Before Ramping Up to 415 VAC Power

RJ Tee
February 20, 2017

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You and your team members have been thinking about switching your cabinets to 415/240 VAC. This will reduce the total number of transformers in your power path, which should in effect reduce power loss — and operating costs — in your facility.  

Hold onto your horses before getting started, though. Here are 10 things you should know before attempting this:

  1. Most international data centers are already doing it: Be prepared to answer some questions from your supervisor or facilities manager. You may receive some pushback about pumping more voltage into your cabinets. That’s because here in the U.S., most data centers are using 240/120, 208/120, or 480/277 VAC systems. 208/120V high leg delta systems are sometimes used, too. But throughout the rest of the world, 400/230 VAC power distribution setups are commonplace. And this trend is quickly spreading throughout North America, as data centers are finding they need more power to support increasing densities and workloads.


  1. Mind your frequency: Most North American IT devices require 60Hz to operate, meaning they require a current that changes direction about 60 times per second. However, most 400 VAC systems run at 50Hz, and so you may run into some performance issues. This is true especially with your heating and cooling systems. You’ll want to keep a close watch on this and look to see if there is a correlation if you start experiencing quality problems.


  1. Determine how to measure power loss: Talk with your team members and discuss whether you want to view power loss as an overhead expense, or an IT issue. Many large data centers — like Google — consider loss from a server’s power cord to be an overhead power expense. Google, for instance, only measures its servers, networking equipment, and storage systems when calculating power usage effectiveness (PUE). Make sure you and your team members are all on the same page before proceeding to eliminate confusion.


To that point, it’s also time to stop calculating PUE if you haven’t already done so. As we discussed in a recent blog post, the American Society of Heating, Refrigerating, and Air Conditioning (ASHRAE) now has a new standard for measuring data center efficiency. And it does not include PUE.


  1. Plan for fault currents: By increasing your system voltage, you will increase the risk for fault currents on your network devices. Make sure that your downstream equipment has a high level of interrupting capacity so that you avoid short circuits that could lead to unplanned system downtime.


  1. Follow safety precautions: By ramping up to 415/240 VAC, you will be operating a system that has more power, and more voltage. It’s not a simple tweak, but a serious change that could have major repercussions if you aren’t careful — namely serious injury or even death for IT personnel. Arc flashes, for instance — or electrical explosions — can sometimes happen when increasing power and voltage. So make sure that your staff members are well educated about the risks that come with the project, and that they are using proper safety gear in the data center.


  1. Ensure all devices are optimized: Most IT devices can operate between either 100 to 120 VAC, or between 200 and 240 VAC. But this is not something you want to guess about. Check each device’s nameplate rating to make sure they are capable of working safely at a higher voltage. If they can, you are golden; running devices at the higher voltages, equaling a lower current for the same power, will increase efficiencies approximately 2 to 3.5 percent.


  1. Watch out for higher costs: While increasing your power and voltage can save you money in the long run, it can also increase operating expenses- regardless, you are able to utilize more power at a more efficient rate. With that in mind, it’s important to monitor your system consistently in order to keep track of daily expenses.


  1. Temperatures may increase, too: Of course, you’ll also want to keep a close watch on your data center’s environmental conditions. This is especially important if you are running heavy workloads. Your best bet is to invest in an intelligent PDU that provides real-time environmental monitoring in addition to power metrics. Look for a solution that can send SNMP alerts, so that your team can spring to action if things go haywire in your data center.


  1. You will lose compatibility with 120V IT devices: Another thing to keep in mind is that some IT equipment may come with a 120 VAC NEMA power cord, which will not be compatible with a CDU in a 415/240 VAC system. You’ll need to switch over to a device that uses an IEC based cord.


  1. Control is critical: The success of this operation will be determined by your ability to understand how your system is performing, and to make remote changes immediately when problems arise. Surprises will undoubtedly occur on the way, and you need to be in a position where you can react quickly.


Server Technology partners with Sunbird to offer Power IQ, which is a centralized, Web-based management console that you can use to manage your 415V setup. With the help of SPM, you can confidently migrate to a higher voltage in your data center safely and confidently.


To learn more information about our 415V PDUs, click here.

Data Center Choices – Part 2 The Power Strikes Back