The generators in a data center are a huge component to back up power in the event of an emergency.  The generators are the lifelines to our racks if there is a utility outage.  It is important to understand where the generators are, how they work, and how they are maintained, as these generators will ultimately be powering the equipment in the data center.

The best place for a data center to store their generators is inside so they are out of the elements.  Another benefit of the generators being inside is that they are less accessible to people.  This creates a more secure environment.

In the event of a power outage the generators will automatically power on.  They take about 7 seconds to fire and get to full load capacity.  During these 7 seconds the uninterrupted power supplies or UPSs are working to maintain the load to keep our racks at full power.  After the generators are at full capacity, the switchgear will register that everything is running on generator power and will switch over to running on generator power as well.  This will allow our data center to remain at full power as long as needed.

Many generators have belly tanks.  Most belly tanks can hold around 1,000 gallons of diesel to power the generator.  Once the belly tank runs out, it is important that our data center has a reserve of diesel in case of an extended outage.  We also want to confirm that if for any reason the reserve of diesel runs out that our data center has a diesel contract to automatically be refilled.  The reserve will allow our data center to run on generator power for many days.

Last but not least, we need to make sure that our data center has monitoring procedures in place for the generators.  A big thing that can get overlooked if there is no monitoring is the charge of the batteries on the generator.  Making sure the batteries are charged and fresh is important as the batteries fire up the alternator, which ultimately starts the generator.

So, when looking at a data center, ask to see the generators and how they work.  That way we know in case of a power emergency all equipment is covered to always have full power.