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Back-up power (UPS)

The difference between modular and monolithic UPSs

Oversized data centres are a thing of the past. But with a lingering fear of running out of capacity, how do you avoid paying for more than you need while simultaneously making sure you have enough? Tailoring power infrastructure for scalability is easy to achieve with today’s readily available modular components. Take a look at how modular and monolithic UPS designs compare for critical power protection.

Eaton Monolithic UPS – cost-effective

Traditional UPS designs are monolithic, meaning that the power rating and specification are fixed. This type of UPS has clear benefits: the design and technical specification are simple and the UPS can be optimised for footprint and price. Eaton offers several monolithic UPSs with different power ratings and frame sizes.

The monolithic UPS is an effective solution when future requirements can be anticipated and few changes are expected. There are some considerations when planning a monolithic UPS system that will be scaled:

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During design

  • As the monolithic UPS is fixed, expanding power means installing additional parallel UPSs
  • In parallel systems, the power rating of each UPS should be the same and the basic UPS rating should be selected accordingly
  • Reservations must be made for additional space, such as spare feeders in the AC switchgear 

During installation

  • Additional sets of cables will be connected to and from the UPS
  • Installing additional UPSs may require supporting the critical load via maintenance bypass

During maintenance

  • Maintenance may require supporting the critical load via maintenance bypass

To find out more about why a UPS should be part of your power back-up strategy

Download Eaton’s guide, Powering Business Continuity

Eaton modular UPS – suits every need

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A modular UPS can grow to accommodate increasing power demand by adding additional power conversion modules into the UPS chassis on an individual basis. This enables you to bring on more power quickly and easily as required, build resiliency into the UPS and optimise efficiency. 

As one of the most energy efficient and cost-effective power sources available, modular UPS units are quickly becoming the popular choice across the industry. Eaton modular UPS systems offer the highest availability for mission-critical applications at the lowest total cost of ownership.

Why you would select a modular UPS?

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Common approaches to modular UPSs

There are two main approaches to achieve modularity in UPSs:
1. Power modules including both double-conversion and bypass components
2. Power modules including double-conversion components, the common bypass being separate in the UPS 
Both approaches can be used to build UPS systems to protect critical loads. There are things to consider when building scalable systems; these will only have a fraction of the maximum power needs on day one, while at the same time, the electrical infrastructure will already be designed for the full capacity. This creates challenges in terms of selectivity, as the UPS has to be sized appropriately for the complete infrastructure. Building scalable systems becomes tricky if we’re not able to size the power of the UPS and the bypass capacity separately.

The Eaton approach to modular UPS design

Each power module in an Eaton modular UPS includes all the components required for double-conversion operation. In addition, there is one common fully rated static bypass per UPS. This topology combines the benefits of modularity, flexibility, availability and scalability, with the resiliency of centralised static bypass.

This flexible modular structure means Eaton UPSs are easy to deploy, since they can be matched for site specific requirements:

  • The centralised bypass enables the upstream and downstream protection to be sized according to the final load
  • UPS capacity can be independently scaled to closely match the critical power need by installing additional power modules
  • Options for UPS and power module level redundancy improve availability/resiliency
  • Easily exchangeable modules minimise the mean time to repair (MTTR)

Is a modular UPS the right choice for your needs?

Contact us to find out more about power protection in a cost-effective UPS design.

Talk to our UPS expert

Summarising the choice between monolithic and modular UPS

  Monolithic UPS-93E G2 UPS Modular UPS -93PM G2 UPS
Scalability ++ +++
Optional internal redundancy No Yes
Optimised double-conversion mode No Yes
Modular for service Yes Yes
Cost €€ €€€
Availability + ++

Monolithic UPS

Fixed UPS power rating, adding power means adding additional units in parallel, a failure in the power electronics will lead to transfer to bypass (unless paralleled UPSs in the system)

Eaton 93e and 93e g2 ups 200 kva open image en us
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Modular UPS

UPS built using power modules housed in a frame, each UPS consisting of up to ~10 power modules. Hot-swappable power modules can be replaced or added while other modules continue to protect the load

Eaton UPSs

Eaton is an intelligent power management company dedicated to improving the quality of life and protecting the environment for people everywhere. We are guided by our commitment to do business right, to operate sustainably and to help our customers manage power ─ today and well into the future. By capitalizing on the global growth trends of electrification and digitalization, we’re accelerating the planet’s transition to renewable energy and helping to solve the world’s most urgent power management challenges.
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