Posted by: Darren Bonawitz
Size – Backup generators need to be sized appropriately in order to provide adequate protection for customers. For example, if a facility has 100 cabinets that are allowed to have a power load of 12kW per cabinet, that is a potential load of 1200kW (not counting supporting infrastructure such as computer room air conditioners, etc.). So if the facility has a single 1000kW generator, that is a warning sign. So you will need to verify what their upgrade plan is at the very least, and if you do not like the answer, walk away.
Load – Much like a UPS, you will want to verify the capacity and load and verify if and how they handle oversubscription. With regard to load, it is important to not just find out the current load on the generator. Instead, verify the committed load on the generator. Customers may only be utilizing a portion of the power delivered to their cabinet currently. If their existing customers add equipment over time, the load will increase even if the facility does not add new customers. So look at both the current and committed load.
Fuel – The fuel will generally either be diesel or natural gas with diesel being more common. In addition, verify the fuel tank capacity, how much fuel is in the tanks currently, and the amount of run time currently and at full load. That way you know how long you can run. On your tour, take the time to visually verify how much fuel is actually in the tanks. If their tanks are not at least 80% full, that could be an indication of a facility not staying on top of their critical infrastructure. At a minimum, I would recommend ensuring they keep at least 24 hours of fuel on site in case of an emergency with more run time being desireable of course. The age and quality of the fuel matters as well. See if they have reports on fuel quality tests, how often they refuel, etc. to ensure fresh fuel.
Maintenance – Ensure the generator(s) are under prevenative maintenance programs and being serviced regularly. Do not be afraid to ask to see proof as well. There are varying opinions on testing schedules, but my recommendation is that testing occurs monthly with a live load test quarterly. This means simulating a power failure and allowing the customers equipment to actually run off the generator’s power to make sure the equipment runs properly should an issue ever arise. Some places may test more frequently which is fine, but I would not recommend a facility that tests less frequently.
Automatic Transfer – It is very important that the provider have an automatic transfer switch (ATS) between the electric utility power and the backup power to eliminate the need for human interaction.
Hopefully the facility you choose never has to utilize their generator in non-scheduled events, but in the event they do, you will be glad you took the time to verify these items.
By: Darren Bonawitz
In this post, a continuation of an ongoing blog series about colocation power, we will be taking a look at electric utility grids/substations. Keep in mind that this is not meant to be a comprehensive discussion but rather a starting point and high level overview of things to consider in regard to grids/substations and colocation. When searching for a colocation provider, or when verifying that your current provider meets your needs, ask the data center or colocation provider what the makeup is for its power grids. A grid serves a specific geographical area and is a network of all the elements, such as power lines and transformers that are necessary to distribute power to a particular area. Some facilities will only be on one power grid whereas some will have the luxury of dual power grids (some even more). This means that if one side of the grid were to fail for any reason, the second could potentially supply power adding an extra level of redundancy.
If a facility does have dual power grids, I recommend making sure it has an automatic transfer switch (ATS), which will automatically switch from grid one to grid two without manual intervention. Speaking of ATSs, make sure there is also an ATS between the utility power and backup power infrastructure. In fact, be sure to ask to see the generator servicing your equipment. Believe it or not, we are aware of unscrupulous data center operators who claim to have generator support when they in fact do not. We will discuss generator support more in a later post. Another item I recommend checking into is whether the transmission lines between the power plant and substation as well as the substation and colocation facility are underground. I won’t go so far as to say it should be a requirement to have underground transmission lines, but I do think it is a competitive advantage if you are comparing facilities that otherwise appear equal.