The R&D department of data centre manufacturer Minkels, part of the publicly traded company Legrand (NYSE Euronext Paris: LR), has extensively tested the thermal usage conditions of the Minkels UPS system in a cold corridor environment over the last few months. This system, which is a fully integrated total concept, was included in the portfolio earlier this year. This means that the Minkels UPS system is now ready to be launched internationally in the data centre market.
The Minkels UPS System, which offers modularly structured power capacity from 20 to 120 kVA and is intended for small and medium-sized server rooms, was originally developed by Minkels’ parent organization Legrand under the name Archimod UPS System. Legrand UPS solutions are used in business-critical environments, including technical areas for airport lighting and surgery departments in hospitals.
Minkels developed the UPS further into a specific solution for data centres, turning it into an integrated total concept that is suitable for data centre environments. “The Minkels UPS System now offers greater flexibility than the original solution,” said Jules Sommers, Product Manager at Minkels. “The new system transcends the boundaries of traditional technical areas, making the UPS extremely well-suited to row-based applications in cold corridors.”
Use of UPS in data centres
The row-based use of an uninterruptable power supply (UPS) in a cold corridor configuration in a server room – i.e. in between data centre racks with hot and cold corridors – is significantly different to using a UPS in a normal technical area with constant and restricted temperature ranges. Temperatures can go up quite some way in data centres with cold corridors, whereas the batteries of the UPS must not get warmer than 25 degrees.
For that reason, the development department at Minkels modified the UPS solution and built ‘cold zone’ protection into it. The solution also has a housing created by Minkels specifically for data centres, allowing the solution to be integrated seamlessly with other modular data centre solutions from Minkels.
Minkels R&D performed exploratory tests to determine the exact usage conditions of the Minkels UPS System in a cold corridor setting, which could then be used for validating the application in a cold corridor. “We’re seeing that the data centre market is using UPS systems that aren’t suitable for data centre applications,” said Sommers. “The exploratory tests will let us guarantee that the Minkels UPS System can function at its optimum under those specific conditions.”
The results of the exploratory thermal tests have been collated in the UPS Thermal Behaviour Test white paper, which can be downloaded from www.minkels.com/whitepaper.
Recommendation: maintain a positive pressure difference
“Minkels had the exploratory tests carried out because applying UPS systems specifically in cold corridors may start making customers wonder,” said Sommers. “We’re the manufacturer, so we’d like to answer those questions proactively. We also want to help users focus their thinking on their applications and exclude all risks relating to the use of a UPS system in a server room with a cold corridor configuration.”
The key conclusions drawn by Minkels R&D in the white paper are that the Minkels UPS system functions very well in a cold corridor environment and that a positive pressure difference of 2 pascals (Pa) is needed to protect the batteries of the UPS and guarantee its performance.
“We advise users of our UPS system in cold corridor configurations to observe a safety margin and maintain a positive pressure difference of 5 pascals,” Sommers added. “The temperature in the cold corridor of the configuration can then get up to 25 degrees Celsius without any problems.”
Setup for the exploratory tests
For the exploratory thermal behaviour tests, Minkels R&D built a server room test environment in a server room of its own, including a cold corridor configuration with both cold and hot corridors and a simulated IT load. Temperature sensors were installed on the batteries, which are the critical components of any UPS system, and Minkels R&D then performed various tests for a given period.
“During the exploratory tests, we varied the pressure difference between the cold and hot corridors,” says Sommers. “We looked to see the pressure levels at which the temperature of the batteries did not increase. We came to the conclusion that a difference of 2 pascals is needed to ensure that the cold corridor conditions apply around the actual batteries of the UPS and that the performance remains the same as that of the UPS when it is not in a cold corridor environment.”
‘UPS Thermal Behaviour Test’ white paper
The results of the exploratory thermal behaviour tests for the server room that Minkels R&D conducted with the Minkels UPS system have been collated in the ‘UPS Thermal Behaviour Test’ white paper. This white paper can be downloaded from: www.minkels.com/whitepaper.