Some years ago, back when modem cards were the rave and were actually installed inside the box of a computer, I remember trying to get on the Internet and all I got was “no connection”. I remember going through every diagnostic within the computer but still “no connection”. Finally, I checked the line, I had dial tone but I did notice some discoloration or what looked like burning on the RJ-11 on the modem card. Yes, it was a burn mark and the night before we had a terrible storm but could lightning have found its way into MY computer? After all, I was the expert, who was protected against surges, strikes and hits but oh yes, lighting had in fact found its way into my computer via the phone line which became the least resistive path to ground!
Just like that little 14.4 baud modem card, lighting hits are all but one of the enemies facing the corporate data center. Data centers which house millions and millions upon millions of bits of information can be wiped out by a number of threats lurking just outside that rather secure data room or facility. Just how does an owner, a corporation, or facility plan, evaluate and maintain the level of protection required? Keep your friends close and your enemies closer, not in the data center, keep your enemies far, far away!
Let’s first define your enemies:
- power surges
- power reductions, brown outs
- power outages
- voltage fluctuations and inconsistencies
- poor or loose connections
- AC to DC power harmonics
- improper sizing of distribution equipment and wiring
- grounding and bonding issues creating noise
- failure to isolate critical power from building power
- communication/data protection and isolation
- inadequate cooling
- inadequate data center space requirements
- poor or inadequate maintenance procedures
The data center designer/engineer/contractor must impress upon his client the importance of eliminating the “enemy” as defined above. Education is the first line of defense in helping the end user understand the strategy. I found more and more data rooms are poorly planned from the beginning. Simple items are usually not considered, facility managers wrestle with data center managers, space is a commodity especially in NYC! Poor planning in terms of space can lead to a shutdown! Cooling and power requirements are two major factors influenced by space. The average power requirement for data centers is 375w/sq-ft. What might start out as six racks of servers with power and cooling may end up with eighteen racks with inadequate power and cooling. “Don’t paint yourself into a corner.”
In any computer sensitive environment, a major cause of problems can be traced back to “grounding” issues. Havoc/electronic noise could be caused due to improper and inadequate grounding issues. Centralizing all of the required “grounding” concerns in any data center is paramount. We have always created a “ground bus” within the data room that is connected to the buildings “Grounding Electrode”. The ground bus allows us to bond each piece of metal to the main grounding electrode. Metal raised floor posts, cabinets, electrical panels, isolated ground bars, non-current carrying conductive members of fiber cables, etc are just some of the required items needed to be bonded to the ground bus in the data room.
Lets discuss the critical power requirements. Every data center that is properly planned requires backup power generation and a Uninterruptable Power Supply, UPS. The UPS basically eliminates voltage inconsistencies during surges, brown outs and the brief time needed before a generator comes up to speed and frequency. Many homeowners today use the small UPS under their desk to ride out the short time power outages or power fluctuations occur. Many large size commercial facilities install UPS units in every rack where servers exist. But is UPS rack scenario a plan to fail? Well, in the homeowner scenario the batteries will last for a brief period of time and unless their home generator kicks in their computer is kapput! In a well planned commercial scenario, the UPS allows the servers to ride out the brief time needed because the batteries in the UPS have been sized for the servers in each rack, once the generator comes up to speed/frequency, BANG, the emergency power is transferred and the UPS is cleaning the power once again. This BANG is transparent and seamless to the sensitive computer equipment. But what do we find in most cases, the rack mounted UPS batteries are not serviced and their DEAD! Therefore, the UPS never had the ride time power to transition them onto the generator! This is why I design a centralized UPS to be installed as part of the initial design. The single UPS, centralized and sized for the entire data center becomes more reliable while reducing maintenance and material costs.
The cooling requirement is an absolute necessity in each an every data room, large or small. It is clearly the most overlooked part of the initial design. I have seen countless data rooms fail due to inadequate and undersized cooling! Once again plan the room with cooling units, chillers, VFD’s, controls and pumps as an integral part of the critical power scenario. How many times have I seen data centers running on critical power but without cooling because one pump is on the non-critical building power and now the whole cooling system is down in the data center! Plan for expansion, keep the room cooler, wear a sweater if you have to but don’t skimp with the cooling.
Seeking out a good electrical contractor is an absolute necessity for the data center to be reliable, efficient and functioning properly. The 2011 NFPA 70, National Electrical Code, Art 645 – Information Technology Equipment, will be just one article used by the licensed, qualified electrical contracting firm. This specific article and others in the NEC will define the minimum requirement the electrical contractor must follow to insure that the data center is wired and installed properly. Third party commissioning of the completed data center is a requirement!
A few important notes to consider:
- the EPA estimates data centers account for 1.5% of the total U.S. power consumption. This will double in the next five years!
- the designer/contractor may need to consider medium voltage distribution, 4160v, where chillers, UPS’s, generators and other equipment can be purchased for more efficiency allowing for less material construction costs and better return on investment, ROI
- Utilizing the European voltage distribution scenario may benefit us here as well, transformers 415/240v/60hz can be used with any electronic equipment, no need to go 240/110v/60hz. Arc-Flash concerns for workers do need to be addressed with the 415/240v scenario
- “green technology” is already impacting designs in data centers. The “low power usage effectiveness”, PUE needs to be addressed in design
Please Note: Electrical wiring and installation requires trained and skilled electricians working in a licensed electrical contracting firm. With all installations, please check with the Authority Having Jurisdiction, AHJ to insure all work is installed correctly.
Kevin J. Breen, is a licensed master electrician in the NYC/NJ area. He works as a consultant and expert witness to the legal community and a design/installer for many private and municipal clients. With over 33 years in the field Mr. Breen can assist you with any electrical/fire/low-voltage/security need you may have. He can be reached at 718 499 7363 or [email protected]