ITC-Electronics - Varistar Server: For high loads

Data technology applications frequently require the use of heavy servers that also generate high heat dissipation losses. Consequently the physical robustness of the cabinet system and its accessory parts is an important characteristic, as is also the efficient dissipation of heat to ensure smooth operation.

Varistar Server - extra robust and with effective heat removal

The Varistar cabinet platform from Schroff has been designed with two frame versions to handle the often very high mechanical loads. The so-called Slimline version offers a maximum load-bearing capacity of up to 400kg. The specially-developed hollow chamber profile used here employs a minimum of material to satisfy the requirements of classes DL5 and DL6 of IEC 61 587-1 for static and dynamic loads. For applications that call for a higher static load-bearing capacity or even earthquake proofing, a second frame version is available. The 'Heavy Duty' version uses the same hollow-chamber profile, but which here is lengthened in the main loading direction and thus even more stable. This version guarantees a maximum static load-bearing capacity of up to 800kg. Seismic tests conducted to IEC 61 587-2 certify the earthquake proofing of the platform to Bellcore Zone 3, and when reinforced in the corners with additional angle sections, up to Bellcore Zone 4.

The Varistar Server cabinet offers a depth of up to 1200mm, thus allowing on the one hand all current server types to be accommodated while on the other also allowing more space for cabling. Perforated front and rear doors allow an air throughflow of up to 78%. A robust pull-out tip-over protection together with heavy load-bearing shelves and slide rails ensure the safe handling and integration of heavy components.

In delivering efficient heat removal in these server cabinets, conventional air cooling comes up increasingly often against its limits. Over about 8kW heat loss per cabinet it is hardly possible to provide adequate cooling from air alone. With high-performance servers in particular, this limit is quickly reached. To address this issue Schroff has developed a complete cabinet system with a heat-removal concept that is independent of its environment: Varistar plus the LHX 20 air-water heat exchanger. This complete system is capable of removing heat from installed equipment at a rate of up to 25kW. The air-water heat exchanger is slotted into the left or right hand side of the cabinet as a single module, so leaving the 19" plane useable throughout its height (42U). The heat exchanger operates in a closed air circuit within the cabinet with a cooling output of up to 3000m3/h. Airflow elements and six fans fitted across the entire height ensure a uniform level of heat removal to all components throughout the cabinet.

Temperature control in the cabinet is done by a microcontroller. Mixing of water inflow and outflow is optimised with a three-way valve and bypass. The cabinet temperature is held constant primarily by control of the water circuit. Only when the three-way valve is opened to 100% is the fan speed set to maximum. If the cabinet temperature then falls, the fan speed is first reduced again and only then the water circuit is controlled. Interfaces (RS 232, RS 485) for alarm and warning signals, for external cabinet monitoring systems and system monitoring aid the smooth operation of the cabinet.

For more information about Schroff see: www.schroff.de