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 third installment dedicated to discussing power in colocation environments, we will be looking at uninterruptable power supplies (UPS). As mentioned before, these blog posts are not meant to be a comprehensive discussion but rather serve as a starting point and high level overview of things to consider when evaluating collocation facilities.
UPS systems, also known as battery backup systems, condition the utility power to defend against issues such as electrical spikes and also provide emergency power from a separate source when utility power is not available. This allows equipment to operate without interruption until a generator is operational and able to support the electrical load. Good questions to ask the collocation provider include the brand, capacity, minimum guaranteed run-time, redundancy and maintenance program for each UPS system. In addition, if you tour the facility, have them show you the exact unit which will service your unit.
Brand – There are several quality UPS manufacturers suitable for data center environments. Some common brands include (in alphabetical order): APC, Eaton (PowerWare), Liebert, MGE and Sentinel Power. The key is to note that not all UPS systems are equal. Make sure you are connected to a larger data center grade unit, which in my opinion, offers better protection and more robust features. UPS systems can be weak points in a power distribution network so this is not an area to skimp, and you do not want your critical infrastructure tied to smaller off-the-shelf units found in smaller hosting and commercial environments.
Capacity – Measured in kilovolt-amps (kVA) or kilowatts (kW). The difference between kVA and kW is what is known as the power factor. kVA multiplied by the power factor equals the kW.
For single-phase power:
KILOWATT (kW) =
VOLTS x AMPERES x POWER FACTOR
For three-phase power:
KILOWATT (kW) =
VOLTS x AMPERES x POWER FACTOR x 1.73
This tells you how big the UPS is and how much equipment can be powered by it. The size of the UPS needs to be proportional to the size of the colocation area and the corresponding electrical load. For example, if the data center operator states that their average customer utilizes 8kW per rack and they have 100 racks with equipment, it is not a good sign if their one and only primary UPS is a 500kW equivalent unit. Mathematically, they do not have enough power to support their existing customers — let alone your new equipment.
Redundancy- If you have mission-critical equipment collocated, it is important to make sure your provider offers A & B power feeds to your cabinet. If you equipment is not dual power supplied, then consider an in-cabinet automatic transfer switch which has inputs for two power feeds which then output to a single power strip. This will protect you if one feed loses power or one path needs to be taken out of service for scheduled maintenance. Remember that scheduled maintenance is a part of a data center environment, and you need to plan for it. Not everyone needs A & B power, and if you don’t need it, having the option to pass on being supplied a B feed could keep your price down. At the same time, you have to be realistic and realize that you cannot cut costs and then complain about outages (whether scheduled or not) when you elected to not take advantage of the available levels of redundancy offered by the facility.
Maintenance Schedule- Ask to see the provider’s maintenance schedule and report. This is to make sure they are testing UPS regularly and maintaining/replacing batteries, capacitors, etc. as necessary. This can also serve as a qualifier that let’s you know if they are being truthful with you. If the provider does not have documentation of their maintenance records, consider another facility. This is a very common area that data center operators cut corners on. All of 1102 GRAND’s UPS systems and supporting infrastructure are under preventative maintenance contracts and serviced on regular schedules. It is not inexpensive to do this, but we firmly believe in the importance of this and know it helps separate us from many competitors.
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.