Elta STDL500-1EC-R Twinflow Centrifugal Box Fan Single Phase EC - 500mm (rectangular spigots)

The Elta STDL500-1EC-R is a Twinflow duty/standby centrifugal box fan for 500mm duct systems, with rectangular spigots sized 498 x 598mm. Two backward curved fans sit side by side in one acoustically lined case: one runs, the other waits on standby. At full speed it moves up to 5508 m³/h free air, about 4968 m³/h at 100 Pa, and still delivers 1753 m³/h against 500 Pa.Each fan has an IP44 EC external rotor motor (220 to 240V single phase, 50/60Hz) with sealed for life bearings, and the case is 1.2mm galvanised mild steel. An auto changeover panel (149-ACO1/EDV) is fitted as standard, switching to the standby fan if the duty fan fails and sharing run hours between the two. Speed is set by the built in commissioning potentiometer or a 0-10V signal, and Elta give a 12 month (1 year) manufacturer warranty. 1 Phase EC Motor Up to 5508 m³/h Speed Controllable What it is best used forThe largest single phase STDL, for warehousing, industrial units, factories and large office or school systems on 500mm ducting where three phase is not available. It moves 5508 m³/h free air and about 4284 m³/h at 200 Pa.At 132 kg it needs proper structural support. If a three phase supply is available, the STDL500-3EC moves more air at every pressure, about 3373 m³/h at 500 Pa against 1753 m³/h here. Not for corrosive, explosive or above +60°C air.Why choose this over alternativesThe point of a twin fan is resilience. A single fan such as the Elta SSDL500-1EC-R Singleflow moves more air in the same duct size (5814 m³/h free air against 5508 m³/h here, and 2192 m³/h at 500 Pa against 1753 m³/h), but when its motor fails the extract stops until someone replaces it. The STDL500-1EC-R keeps running on its standby fan, the panel gives normally open fail and run contacts for a BMS or alarm, and the duty share means neither motor does all the hours. Choose it for windowless toilets, risers and any system where a dead fan means a complaint or a breach of the ventilation design; choose the Singleflow