Compaq 3000 manual Shelf Cooling, Controller Shelf Power Supplies

RAID Array 3000 Controller Shelf

1.5.4 Shelf Cooling

The device I/O module ensures that the SBBs and Controller Shelf are at the proper operating temperature by monitoring the operational status of the blowers and sensing the ambient air temperature.

The two dual-speed blowers cool all the shelf components by drawing ambient air in through the front of the SBBs and exhausting it out the rear of the Con- troller Shelf. The blowers normally operate at low speed. Reduction of the air- flow through the shelf or an increase in the ambient temperature may result in overheating causing component failure or data corruption.

The device I/O module ambient temperature circuitry monitors the air flowing through the module. If the ambient temperature exceeds 32ºC + 2º C, the cir- cuitry:

∙Turns on both blower LEDs

∙Causes both blowers to switch to the high-speed mode to increase air flow through the shelf

When the I/O module circuitry detects a blower that is not operating or not oper- ating at the correct RPM, this circuitry:

∙Turns ON a LED on the I/O module front panel that identifies the defective blower

∙Causes the operational blower to switch to the high-speed mode to increase air flow through the shelf, thereby maintaining the proper operating envi- ronment

NOTE

The Controller Shelf power supply status LEDs also display blower error conditions. However, they do not identify the defective blower, nor do they report ambient air temperature faults.

1.5.5 Controller Shelf Power Supplies

The Controller Shelf has two interchangeable, air-cooled, 180 watt AC power supply SBBs (see Figure 1–8) located at the left two SBB slots of the shelf. The power supplies provide redundant power if one of the units should malfunction. Each supply provides +5 and +12 Vdc to power the RAID controller(s), the host I/O modules, the device I/O module, and the blowers. The first power supply from the left edge of the shelf is designated as "A" and the second as "B". The SBB front panel has an ac input power receptacle, a power supply status LED, and a shelf status LED.

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