HP Surestore Disk Array FC60 HP SureStore E Disk Array 12H User's and Service - Page 238

Appendix D. Back-to-Back Racking Product Description Other Documentation This document constitutes an overview of the back-to-back racking installation. Detailed installation instructions accompany the other kits. Other documentation includes: E7687-90001 A4915-96000 E7670-90001 C2785-90002 7687A HP 200-240V Exhaust Fan Assembly Installation Guide HP SureStore E Disk Array 12H Power Upgrade Kit, Quick Installation Guide Power Distribution Unit Kit Installation Instructions Computer Support Rail Kit Installation Instructions Features The exhaust fan module contains three cooling fans. The module operates in a redundant power configuration; that is, the module draws power from two of the rack's PDUs (one fan draws from one PDU, the other two fans draw power from another PDU). If power from one of the PDUs fails, one or two fans drawing power from the other PDU will continue to provide cooling for the rack. If one of the fans fails physically, the remaining fans in the fan module will continue to cool the rack. However, after a fan failure, it is recommended that the failed unit be replaced within 48 hours, so that disk drive reliability is not compromised. LED Indicators Front panel indicator LEDs show normal operation and fan failures. Power failures are indicated by no LEDs being lit. Power Redundancy The disk arrays in the rack can be configured for power redundancy. In redundant mode, if power to one of the rack's PDUs fails, the other two PDUs will continue to power all disk array units. To provide power redundancy, each PDU must be connected to a separate, dependable (or UPS) power source. Racking 238