Five steps to maximise UPS efficiency

Power Control
22 Jul 2020

Environmental initiatives and a push for ‘green building’ methods have seen the traditional approach to specifying UPS systems overhauled. Reliability is no longer is the sole system focus as both reliability and efficiency are at the forefront of UPS calculations.

Today’s UPS systems can achieve efficiencies upwards of 98%, a figure that is also important for minimising running costs and achieving optimum battery runtime in the event of a power failure. All too often it is how the UPS systems are implemented that is the largest contributor to inefficiencies. Specifiers without comprehensive technical knowledge often quote for over sized systems resulting in inefficiencies from day 1.

Additionally, if not positioned, maintained, or operated correctly, the UPS will not achieve its optimum efficiency. With this is mind, we look at 5 practical ways to maximise the efficiency of a UPS system.

  1. Correctly sizing and balancing the UPS

Firstly, load balancing is one of the most important contributing factors in achieving optimal operating efficiency. In a three phase UPS system, each phase works together to carry the critical power load, this load should be evenly distributed across all three phases.

Secondly, the UPS should be loaded to a suitable level. Operating the UPS at a higher load leads to less energy being wasted. If run below 30% capacity, the operating efficiency would be substantially compromised. Older UPS systems, especially those that operate on transformer-based technology, have a lower tolerance when run on low load levels, some only achieving 80-85% efficiency.

Modular UPS systems are often used in large data centres where the capacity can be increased as the load requirements grow.

  1. UPS Maintenance

Whilst modern UPS systems are more reliable than the incumbent technologies, they still include consumable components and there are a number of extraneous variables that can affect the performance and efficiency of the system. Firmware updates are also crucial for ensuring the UPS system is working at peak efficiency. The revisions come in numerous forms and are not all relevant to the system. Therefore, a trained UPS maintenance engineer is required to install them.

Read more about UPS maintenance in this blog post

  1. ECO Mode/Module Hibernation

Running a UPS in its dedicated ECO mode can generate efficiencies of up to 98-99% in modern systems.

Before switching to ECO mode considerations should be given to the sensitivity of the load being supported. Running the uninterruptible power supply in eco mode means it is effectively in bypass mode with the inverter inactive until a mains failure is detected. There will be a short delay in switch over to battery power which could be detrimental to highly sensitive loads.

Huawei has developed a hibernation function for their modular UPS systems. Unused modules can be put into a hibernation mode and these can be cycled to reduce the amount of power being used.

  1. Install UPS in cool dry place

UPS systems contain fragile electrical components that require stable and precise environmental conditions, specified by individual UPS manufacturers, to ensure maximum longevity including peak efficiency.

Extreme temperatures and humidity cause UPS battery degradation, where particles in the air can cause significant blockages and any salt in the air can cause corrosion. A UPS which is having to combat the effects of a poor environment will not be operating at peak efficiency.

Read more about the effects of environmental conditions on a UPS system in this blog

  1. UPS upgrade

Load requirements change over time, if the UPS system is over 10 years old, it might be time to consider upgrading to the latest technology. Not only are legacy systems at a greater risk of component failure but it is likely that the load requirements of a site have changed.

Power Control offer free site surveys in which a lifecycle report and efficiency audit will be able to establish exactly how effective the existing UPS is and whether it was sized correctly. The team will put together a detailed analysis of the expected cost savings if the UPS was to be upgraded to a new system.