The trays are populated with fans operating from 12, 24 or 48 VDC or 115 or 230 VAC, and each unit is available with or without a replaceable filter, which is contained within the overall 1U height. Each DC fan is rated at 170 m3/h, the 115 VAC fans at 180 m3/h and the 230VAC fans at 160 m3/h.
The intelligent units are managed by a controller that restricts the fans at half speed up to 35°C, subsequently linearly increases the speed to maximum at 55°C, ensuring that sound levels and energy consumption are optimised. If one fan in a bank of three fails, the remaining fans increase to full speed and an alarm is generated; if the thermal sensor fails open or short circuit, if the temperature exceeds 65°C the fans all increase to full speed and an alarm is generated. It also monitors for power fail, generating an alarm when detected. Monitored trays, in which all the fans constantly run at full speed and an alarm is generated on fan or power fail, are also available. Alarm conditions are indicated by local audible and visual warnings and remotely by volt-free changeover contacts.
For applications that require a specific fan type, the trays are also available in chassis format, suitable for mounting any 119mm square fan, up to 38mm thick for the standard tray or 32mm thick for the filtered version.