EC fans help cool the world’s largest telescope

CHILE: EBM-Papst is supplying EC fans to cool lasers at the Extremely Large Telescope (ELT) astronomical observatory under construction in the Atacama Desert of northern Chile.

Part of the European Southern Observatory (ESO) agency, the ELT will study dark matter, Earth-like planets and extraterrestrial life forms.

Located on top of Cerro Armazones mountain, the €1.45bn observatory project will include 46 air handling units designed by Portuguese company Ocram Clima.

EBM-Papst is supplying 28 FanGrids with 168 RadiPac EC fans for this project. They will be used in the AHUs for the laser systems. 

Up to eight guiding star laser systems will be used to ensure that the ELT can take precise images of space. To safeguard their operation, these systems must be supplied around the clock with pure and perfectly temperature-controlled air. 

At an altitude of around 3,000m in a region that is subject to frequent earthquakes, fine desert sand and dust, and variable weather conditions, the conditions placed very complex demands on the fan solution.

EBM-Papst developed a tailored plug and play solution that integrates all components and minimises Ocram’s installation and validation effort. It proposed the use of FanGrids, with six individual EC fans stacked and assembled on top of each other. These redundancies ensure the systems’ greater operational reliability, efficiency and service life.

Due to the requirements, the EBM-Papst team made technical modifications to the fans. To protect them from possible damaging vibration, the RadiPac fans are equipped with automatic resonance detection as standard. Thanks to active power factor correction, EBM-Papst was also able to guarantee a maximum value of 5% to meet the ELT’s strict limit value of 10% for current harmonics. 

The first units were shipped to Chile last year and assembled by the Ocram team. On-site measurements are now being performed to validate the plug and play solution.