Beyond the sparkling clean hallways, painstakingly temperature-controlled hot and cold aisles, and the glitter of the flashing lights through server racks, there are considerable safety hazards in any data center.
Data center operators are under scrutiny when it comes to performing maintenance on PDUs with branch circuits. In the past, this was attempted without shutting down critical loads such as when plug-in units are inserted or removed from a live bus. This procedure places data center workers at potential risk and in some cases; this “hot work” leads to injuries and even death.
It's understandable why data centers cannot be shut down to perform maintenance, but these procedures should never jeopardize employee safety. Compare the maintenance of live circuits to tuning a NASCAR engine while it's traveling down the track at 225 miles per hour.
The safety concern is directly applicable to power distribution units (PDUs). PDUs are a staple for data center applications and a vital role in the power chain. Given this importance, it is imperative to understand how PDUs can be designed to address safety concerns.
A recent innovation that has been introduced over the last few years to mitigate the risk of injury is the introduction of products designed to IEC standards to the U.S. market. These offerings have been tested and listed to the appropriate UL listing. A particularly good one to note is the listing of Form 4 Type 7 low voltage switchgear to UL 891 that many companies offer.
The Form 4 Type 7 low voltage switchgear incorporates compartmentalization and isolation within the PDU that enhances safety during maintenance procedures. This is particularly important for applications that have a high potential for arc flash or short circuits that usually occur between live conductors.
Compartmentalization and isolation is an important enhancement to the legacy PDUs data centers typically use. These legacy devices are an open style construction that have limited or even no compartmentalization. This is important to note, as these limitations are not conducive to arc flash safety and not compliant with NFPA70E. Because of these inherent safety hazards, data centers that are using these types of PDUs need to provide the maximum level of PPE and schedule a shutdown during maintenance procedures.
PDUs Safety Gets Even Better
In 2016 new products have been introduced that are inspired by the IEC standards of separation and address the deficiencies of legacy PDUs. This new generation offers separation of the transformer from other components, which is critically important because the transformer represents the greatest potential danger from human error. They also offer more compartmentalization for the input breaker, the monitoring and the output distribution. These features simplify maintenance, greatly enhance safety and reduce the amount of PPE required to perform PDU maintenance.
Much like the way the railroads changed just about every aspect of lives in the 1800s, the data center’s impact on today's society is revolutionary. The processing power of yesteryear’s desktop computers is now carried within the pockets and even is worn on our wrists. The importance of the data centers to process all these applications will become even more important as The Internet of Things (IoT) begins to take hold and common household appliances will communicate data across the Internet.
To support all these data hungry devices, more servers need to be deployed, which requires these facilities to consume additional power. Data center engineers know that higher system requirement provide efficiency gains down to the rack level. Since more power is delivered with lower impedance, fault currents can be much higher than in legacy designs. Therefore, it is imperative to embrace a new generation of safer PDUs that decrease the risk of injury during maintenance procedures. After all, no application delivery is worth bodily harm or worse.