The Best UPS Model For You
Everybody wants to find their “match.” This is true in both life and in business: finding the right job, the right partner or the right community is important to us. This is also true in the critical power world. The idea of finding the right UPS “match” for your critical power applications by looking at several main factors is very important for the application to function most efficiently and effectively. Today, we will break down the three important categories to consider when making your UPS selection.
There are three main categories that can help match UPS units with your application:
- Equipment Load– How large the load is that the UPS will handle, and the power factor or type of equipment load.
- Environmental- The environment and location that the UPS is being installed in.
- Type of Technology– Is the technology on the UPS serviceable by the end user, or does it have proprietary technology only serviceable by the OEM? This is very important as it may impact emergency response and serviceability of the UPS.
Let’s break down these categories and discuss each in more detail.
Type of Equipment Load– Also described as the type of power demand. A full understanding of both the load profile, as well as your equipment type should be considered. Servers, pumps, controls, and network gear all have different load profiles that need to be identified. For example, a CAT scan machine in a hospital setting certainly has different load needs than emergency lighting.
Be sure to discuss capacity requirements with your critical power experts to determine the appropriate size and capacity of your UPS system. Some equipment may have unique power characteristics, including inrush currents during increase load or startup.
The other thing to consider with loads is whether the load is a leading (capacitive) or lagging (inductive) power factor load. An inductive load, or lagging power factor, is where the current lags the voltage. The load will “consume” reactive power, meaning that as the reactive power travels through the circuit is consumed by the inductive load. A capacitive load, or leading power factor, is one where the current leads the voltage. The load will “supply” reactive power, and the reactive component is negative as reactive power is being supplied to the circuit. Each UPS system will have published specifications on their ability to handle both capacitive or inductive loads
In addition, the output power factor (PF) of the UPS system will also vary from a 1.0 PF to as low as a .7PF or even lower in some older technology. The power factor of a UPS system output can impact your available real power, or kW available to your critical loads. It is also crucial to understand when sizing your system. We will cover the difference between volt amps (VA) and watts in another article.
Environmental– Means the types of potential environments for the UPS to be installed in. Some examples are:
- “Clean Room”- A clean, dust, free, and air-conditioned space for the UPS to exist. This space is also likely heat and humidity controlled. An example of this would be a data center or an office space.
- Industrial- This space will have a number of factors to consider. The environment can be dirty, have a lot of debris around, be warm, moist, humid, and possibly dry. The UPS installed here would have to be robust and the battery technology may be different, such as lithium-ion UPS batteries, or a flywheel UPS rather than a typical battery option.
If we look more closely at an industrial environment, specific examples can help illustrate what someone might have to accommodate. One example is if the UPS has the ability to easily install air filters. If there are modular fans in front of the unit, you might not be able to get to the air filter easily. A second example is a caustic environment that may require coated boards or a higher rated NEMA enclosure that can protect the UPS from corrosion, grease, or other deteriorating conditions.
User Preferences– Many things can come into play in this category, including cost, efficiency and reliability, available space, and control of software.
- Modular UPS Systems– These systems are often used where a smaller footprint may be required for the UPS, or where the load requirements may change in the future. Generally, these systems are scalable, and allow for faster serviceability in the event of a component failure. Since the most common failed components are housed in a replaceable module, the mean-time-to-repair (MTTR) is faster than a traditional UPS. Modular UPS systems also provide for component redundancy, increasing reliability without the need for a secondary UPS.
- Reliability– Considering how often specific components typically need repair or replacement, how much redundancy is built into a unit, and how easy maintenance is to perform are all factors in the overall reliability of a UPS unit.
- Life Cycle Cost (TCO)– Whenever Total Cost of Ownership (TCO) is evaluated, both CapEx (initial costs) and OpEx (operational costs over time) costs need to be considered at the same time. For example, a modular or transformerless UPS may have initial advantages in terms of cost, footprint, and flexibility, but a transformer-based UPS may begin to look better if an input or output isolation transformer needs to be added to a transformerless model.
- Proprietary Software– If the UPS contains software that is proprietary to the OEM, and if the OEM is the only one that can access the software, this may increase troubleshooting costs and potential repair time with the provider, and also make software modifications and upgrades more cumbersome.
Trying to find your UPS match, but stuck on one or more of these factors? QPS has years of experience and Certified Power Quality Professionals (CPQ) on-hand to help take the guesswork out of this important decision. Contact us today to set up a site visit, or discussion to help you choose the right UPS system for your facility.