This chapter describes the function and physical components of the power bay in the following sections:
The power bay is a 3U-high enclosure that holds a maximum of six hot-swappable distributed power supply modules (DPSs). The power bay monitors, controls, and supplies AC power to the DPSs. Although the power bay can hold a maximum of six DPSs, in this system the power bay contains three or five DPSs. The compute racks require power bays with five DPSs and the I/O racks require power bays with three DPSs.
Each DPS inputs single-phase AC voltage and outputs 950 W at 48 VDC and 42 W at 12 VDC. The outputs of the DPSs are bused together. For example, when the power bay contains three DPSs, the DPSs are bused together to provide approximately 2,760 W of 48 VDC power and 135 W of 12 VDC power.
Figure 9-1 shows front and rear views of the power bay.
The power bay has the following features:
3U-high enclosure
Six AC input connectors
Eight DC output connectors
Fault reset button
This section describes the external components located on the front and rear panels of the power bay.
The front of the power bay seats the distributed power supplies (see Figure 9-2). When the power bay contains three power supplies, the supplies reside in locations 4, 5, and 6.
The power bay module has eight DC output connectors (see Figure 9-3). A power cord connects one output connector to a C-brick, R-brick, IX-brick, or PX-brick. This connection provides 12-VDC standby power, 48-VDC power, and monitoring signals.
 | Note: The L1 controller of a connecting module can monitor the status and enable the output ports of the power bay. |
The power bay module also has six AC input connectors, one for each power supply location. For example, when the power bay contains three power supplies, connectors 4, 5, and 6 connect to the power distribution strip (PDS). When the power bay contains six power supplies, connectors 1, 2 and 3 also connect to the PDS. The reset button is used to reset the power bay when a fault condition occurs.
The distributed power supplies (DPSs) are air-cooled devices; each DPS has two fans that move air from the front of the rack to the rear of the rack. Figure 9-4 shows front and rear views of a DPS.
Each DPS has the following LEDs:
Power
Predictive fan fail (PFAIL)
Power supply fail (FAIL)
The input and output power connectors shown in the rear view picture of the power supply interconnect with the power bay through a motherboard located inside the power bay.
Table 9-1 lists conditions of the power supplies and the corresponding states of the LEDs.
Table 9-1. Power Supply LED States
| LED States |
|
|
|---|---|---|---|
Power Supply Condition | Power (Green) | PFAIL (Amber) | FAIL (Amber) |
AC voltage not applied to all power supplies | Off | Off | Off |
AC voltage not applied to this power supply | Off | Off | On |
AC voltage present; standby voltage on | Blinking | Off | Off |
Power supply DC outputs on | On | Off | Off |
Power supply failure | Off | Off | On |
Current limit reached on 48-VDC output | On | Off | Blinking |
Predictive failure | On | Blinking | Off |
Each power supply also contains a serial ID EEPROM that identifies the model and serial number of the supply. The L1 controller of a connecting module reads this information.
Table 9-2 lists the technical specifications of the power bay.
Table 9-2. Power Bay Technical Specifications
Characteristic | Specification |
|---|---|
Height | 5.12 in. (130.04 mm) |
Width | 17.5 in. (444.5 mm) |
Depth | 23.87 in. (606.3 mm) |
Weight | 64.5 lb (29.26 kg) |
Input voltage | 220 VAC |
Output voltage | 12 VDC and 48 VDC |
Table 9-3 lists the technical specifications of the distributed power supplies.
Table 9-3. Power Supply Technical Specifications
Characteristic | Specification |
|---|---|
Height | 5 in. (127 mm) |
Width | 2.8 in. (71.12 mm) |
Depth | 13 in. (330.2 mm) |
Weight | 7.5 lb (3.40 kg) |
Input voltage | 220 VAC |
Output voltage | 12 VDC and 48 VDC |