3 phase data centre solutions - the future is green, so says Theo Spittel of Data and Power Solutions

28th November 2008

 

Theo Spittel of Data and Power Solutions says that three phase power distribution up to rack level should be included as a vital element of any new data centre's infrastructure.

 

The challenge of dealing with an overloaded and inflexible infrastructure is a common problem for many UK data centre managers as high density computing and increased server deployment takes its toll. Innovations such as dynamic smart cooling and server virtualisation can help overcome some power distribution issues but they don't solve the entire myriad of problems.

 

Current installations can be severely restricted by the standard design practices that existed when they were built and for the majority that includes single phase power distribution throughout. However, design consultants and engineers in the process of planning new data centres are rapidly becoming aware of the advantages of running three phase power distribution straight to the racks' PDUs, rather than reverting to single phase at building entry point.

 

Three phase is the most efficient way to produce and distribute electricity. However, even though power is distributed through the UK grid as three phase once it reaches commercial premises it is normally split into single phase. But, new data centre installations cabling should continue up to the rack in three phase in order to maximise a raft of benefits.

 

Once at the rack splitting into single phase distribution can easily be done from 63 Amps/415V down to 32 or16 Amps/240V. The main advantages derived from using three phase distribution to racks are not only the creation of more space for future expansion but also the potential to save a small fortune on installation and running costs.

 

The expansive tracts of data centre under-floor cabling decrease the amount of space available in which chilled air can circulate, adding to the cooling burden. By running three phase power distribution to rack level, there is more space available to force chilled air through the flooring, making its operation more efficient. In addition, ongoing power consumption efficiencies can be achieved by balancing the load equally on all three phases by using a three phase monitored PDU.

 

Currently it is a significant potential reduction in the installation costs that make three phase an attractive proposition. In June 2008 copper was selling at a staggering $8,355 per tonne and it is not likely to get any cheaper as world demand for the finite resource is increasing. Therefore, any opportunity to cut down on the miles of cabling used in a new installation makes sound economic sense. Plus, less cabling also means less time to install and therefore a reduction in contractors cost.

 

Although three phase cables are thicker than their single phase equivalent, only one third of the total amount is needed so the aggregated amount of cabling is still less bulky than for a complete single phase installation. Additionally, because only five wires are required in three phase instead of the usual single phase nine, there is an immediate saving on cabling of 44% throughout the installation, and the subsequent reduction in copper required also lessens the completed data centre's carbon footprint.

 

As a result of the environmental and potential fiscal savings any data centres currently on the drawing board should definitely include three phase power distribution as standard. Not only will they benefit from lower costs at installation stage, they can also benefit from reduced ongoing power bills form more efficient load balancing, and they will be greener; good news for everyone concerned.