[raid]

While many DC’s are focusing on power costs, because power is becoming a very expensive commodity, at the same time it has also become more unreliable. The world’s ever increasing demand for power coupled with nature’s fury, is placing an ever increasing strain on the energy providers aging infrastructure. Even first world counties are struggling to maintain the quality of power they once did.

Blackouts, Brownouts, surges and sags have all becoming common place so how is your DC protected?

For surges you install surge diverters and for the others you have your backup generators, you have it all covered. So when do you start your generators.

Believe it or not, most DC’s that I have seen have just a single parameter to determine when their generators start that is; a phase fail for a set period of time e.g. 10 seconds.

Let’s look at a few real worked events and see how this system works. A natural event (forest fires, storms etc) cause problems for the utilities HV transmission. In order to maintain power the utilities start HV switching around the problem areas. This can be a long slow process, you just can’t just find MW’s of capacity when you need it, this must be carefully managed or you will bring the entire grid down.

1. During power switching, HV transients are generated and they will absorbed by the DC’s surge diverters. These devices are sacrificial, meaning that when they absorb a surge part of their capacity is lost. If a surge diverter is hit hard enough or often enough it will fail, providing no protection for the DC’s infrastructure. The generators will not start so there is nothing to protect the DC. Some UPS’s will see the transients and go to battery, but others won’t.

What would happen if a surge took out the generator controls?

2. During power switching there are often times when they cannot meet demand leading to sags or even brownouts. What happens in a DC is that the UPS’s would see out of tolerance power and go to battery.

How will the rest of the DC infrastructure respond? Chillers and CRAC units will probably trip out. Will the Chillers and CRAC’s be able to restart with poor quality power? In most cases nobody knows.

While the IT is protected by the UPS, the UPS cannot stay on batteries forever, they need to get back to reliable power so that they can recharge their batteries.

All of the above examples have happened and all were not happy days.

What normally happens is that it’s left to the FM as a judgment call. So if the FM runs the generators all the time the fuel budget could blowout. If the FM does not run the generators and infrastructure is damaged there will need to be a very good reason why they placed the DC at such risk. What most FM’s do is escalate, so the it’s somebody else’s responsibility and who can blame them.

A CIO takes responsibility for all of the IT in the company and is remunerated accordingly. The FM believe it or not has the same responsibility, but on a slightly lower salary package. There has to be a better way of protecting the DC without placing the responsibility on the FM.

Here is my question, if you where to set rules (procedures) for starting generators or even automate the system what are your recommended starting parameters?