HP BladeSystem p-Class Enclosure Installation Guide
March 2005 (Second Edition) Part Number 354556-002
Copyright 2005 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. March 2005 (Second Edition) Part Number 354556-002

Contents

Planning the installation 7
Rack requirements..... 7 Warnings, cautions, and importants.... 8 Space and airflow requirements.... 11 Temperature requirements..... 12 Power requirements.... 12 Grounding requirements.... 13
Installing HP BladeSystem p-Class enclosures
Installation overview.... 15 Measuring with the rack template.... 16 Installing the rack rails and cage nuts... 16 Installing the HP BladeSystem p-Class 1U Power Enclosure rack rails.. 17 Installing the rack rails (3U power supply and server blade enclosures).. 17 Installing the cage nuts.... 20 Installing HP BladeSystem p-Class enclosures into the rack... 20 Installing HP BladeSystem p-Class 1U Power Enclosures... 21 Identifying HP BladeSystem p-Class 1U Power Supply Enclosure bays. 21 Installing an HP BladeSystem 1U Power Supply.. 22 Installing HP BladeSystem p-Class 3U Power Enclosures... 23 Identifying HP BladeSystem p-Class 3U Power Enclosure bays.. 23 Installing an HP BladeSystem 3U Power Supply.. 24 Installing HP BladeSystem p-Class Server Blade Enclosures.. 25 Installing interconnects..... 25 Installing HP BladeSystem interconnect modules and RJ-45 patch panels.. 26 Installing HP BladeSystem interconnect modules and interconnect switches. 27
Cabling and powering up the system
System cabling overview.... 29 Identifying HP BladeSystem p-Class 1U Power Enclosure components.. 31 Identifying HP BladeSystem p-Class 3U Power Enclosure and Server Blade Enclosure components32 Installing power distribution devices.... 33 Installing a scalable bus bar kit.... 35 Installing a mini bus bar kit.... 36 Installing a power bus box.... 36 Installing the power connectors.... 38 Cabling the management modules.... 39
Management cabling guidelines... 39 Additional guidelines for a 42U solution... 40 Connecting the management module cables... 40 Connecting the HP BladeSystem p-Class 1U Management Link Cable.. 42 Connecting to iLO.... 43 Cabling the network to the system.... 43 Connecting the HP BladeSystem p-Class 1U DC power cable to the server blade enclosure. 44 Connecting power cables to a mini bus bar... 44 Removing the mini bus bar cover... 45 Connecting power cables to the mini bus bar... 45 Replacing the mini bus bar cover... 46 Securing the mini bus bars.... 47 Connecting power cables to a scalable bus bar.... 47 Removing the scalable bus bar covers... 48 Connecting power cables to the scalable bus bar... 48 Replacing the scalable bus bar cover... 49 Securing the scalable bus bars... 50 Connecting the load-balancing signal cable... 50 Connecting facility DC power to the power distribution bus bars... 51 Installing the cable bracket.... 52 Configuration examples.... 52 Scalable bus bar configuration example... 53 Two mini bus bar configuration example... 54 Redundant mini bus bar configuration example... 55 Full rack 42U solution with two pairs of mini bus bars... 56 Configuring the Dynamic Power Saver.... 57 Powering up the system.... 59 Powering up the system (HP BladeSystem p-Class 1U Power Enclosure).. 59 Powering up the system (HP BladeSystem p-Class 3U Power Enclosure).. 60 Powering up the system (facility DC)... 61 Completing the installation.... 62

LEDs, buttons, and switches
LEDs..... 63 Server blade enclosure LEDs... 63 Server blade management module LEDs... 64 Power management module LEDs.... 65 HP BladeSystem p-Class 1U Power Enclosure LEDs.. 67 HP BladeSystem p-Class 3U Power Enclosure LEDs.. 69 HP BladeSystem p-Class 1U Power Supply LEDs... 70 HP BladeSystem p-Class 3U Power Supply LEDs... 71 Buttons and switches.... 71 Reset and UID buttons... 72 Power configuration switches.... 72

Troubleshooting

Troubleshooting resources..... 77 Important safety information.... 77 Symbols on equipment.... 78 Warnings and cautions... 79
Regulatory compliance notices
Regulatory compliance identification numbers.... 83 Federal Communications Commission notice... 84 FCC rating label..... 84 Class A equipment.... 84 Class B equipment.... 85 Declaration of conformity for products marked with the FCC logo, United States only. 85 Modifications..... 86 Cables..... 86 Canadian notice (Avis Canadien)... 86 European Union regulatory notice.... 87 Japanese notice..... 88 Power cord statement for Japan.... 88 BSMI notice..... 88 Korean notice A&B..... 89 Laser compliance.... 89 Battery replacement notice..... 90 Taiwan battery recycling notice.... 91

Electrostatic discharge

Preventing electrostatic discharge.... 93 Grounding methods to prevent electrostatic discharge... 94

Technical support

Before you contact HP.... 95 HP contact information..... 95
Acronyms and abbreviations Index

97 103

Planning the installation
In this section Rack requirements....7 Warnings, cautions, and importants...8 Space and airflow requirements....11 Temperature requirements...12 Power requirements.....12 Grounding requirements....13

Rack requirements

The HP BladeSystem p-Class Server Blade Enclosure is compatible with the following racks: 41U, 33U, and 25U HP Rack System/E 42U, 36U, and 22U Compaq branded 10000 and 9000 Series racks
NOTE: The system is optimized for 10000 Series racks.
Telco racks Third-party rack cabinets that meet the following requirements: Width - 48.26 cm (19 in) Depth - 73.66 cm (29 in) between front and rear RETMA rails Clearance - 7.62 cm (3 in) minimum clearance between rear RETMA rails and rear rack door to accommodate system cabling Open area - minimum of 65 percent open area to provide adequate airflow through any rack front or rear doors
Warnings, cautions, and importants
WARNING: To reduce the risk of personal injury or damage to equipment, heed all warnings and cautions throughout the installation instructions.
WARNING: To reduce the risk of personal injury or damage to the equipment, be sure that: The leveling jacks are extended to the floor. The full weight of the rack rests on the leveling jacks. The stabilizing feet are attached to the rack if it is a single-rack installation. The racks are coupled together in multiple-rack installations. Only one component is extended at a time. A rack may become unstable if more than one component is extended for any reason.

WARNING: To reduce the risk of personal injury or equipment damage when unloading a rack: At least two people are needed to safely unload the rack from the pallet. An empty 42U rack can weigh as much as 115 kg (253 lb), can stand more than 2.1 m (7 ft) tall, and may become unstable when being moved on its casters. Never stand in front of the rack when it is rolling down the ramp from the pallet. Always handle the rack from both sides.
WARNING: To reduce the risk of personal injury or equipment damage, be sure that the rack is adequately stabilized before extending a component from the rack.
WARNING: The power enclosure and the server blade enclosure are very heavy. To reduce the risk of personal injury or damage to the equipment: Observe local occupational health and safety requirements and guidelines for manual material handling. Remove hot-plug power supplies and server blades from their enclosures before installing or removing the enclosures. Use caution and get help to lift and stabilize enclosures during installation or removal, especially when the enclosure is not fastened to the rack.
WARNING: To reduce the risk of personal injury or damage to the equipment, you must adequately support enclosures during installation and removal.
WARNING: Always use at least two people to lift an enclosure into the rack. If the enclosure is being loaded into the rack above chest level, a third person must assist with aligning the enclosure with the rails while the other two people support the weight of the enclosure.
WARNING: Before installing an enclosure in the rack, be sure that all hot-plug power supplies, server blades, and interconnects are removed from the enclosure. Blanks can be left in the enclosure.
WARNING: Be sure to install enclosures starting from the bottom of the rack and work your way up the rack.
These symbols, on power supplies or systems, indicate that the equipment is supplied by multiple sources of power. WARNING: To reduce the risk of injury from electric shock, remove all power cords to completely disconnect power from the system.
Each power enclosure has two or more power supply cords. A single rack or cabinet may contain more than one power enclosure. Power may be supplied in a redundant fashion. Removing any single source of power does not necessarily remove power from any portion of the system. When performing any service other than hot-plug module replacement, you must completely disconnect all power to that portion of the system. When performing service procedures on server blade enclosures, ensure that both A and B DC power feeds are disconnected from the enclosure before servicing. When performing service procedures on power enclosures, shut off the circuit breakers to both A and B AC power feeds and then disconnect both power cords from the wall outlet before servicing.

System cabling overview

After all system hardware is installed, cable the components. Refer to the HP ProLiant BL System Best Practices Guide on the Documentation CD or the HP website (http://www.hp.com) for HP recommendations on cable ordering.
WARNING: To reduce the risk of electric shock or injury due to high-current electrical energy, be sure that all power is completely disconnected at the source before beginning any power connections to the power bus bars or power bus box.
To cable the system: 1. Cable the management modules. Refer to "Cabling the management modules (on page 39)."
2. Connect the network cables to the interconnects. Refer to the documentation that came with the interconnects or to the HP ProLiant BL System Best Practices Guide on the Documentation CD or on the HP website (http://www.hp.com/go/bizsupport).
WARNING: Be sure that all circuit breakers are locked in the off position before connecting any power components.
3. If you are using a facility AC power source, complete the following steps: a. If you are installing the HP BladeSystem p-Class 1U Power Enclosure, connect the power cables from the power enclosure to the server blade enclosure. Refer to "Connecting the HP BladeSystem p-Class 1U DC Power Cable to the server blade enclosure (on page 44)." b. If you are installing the HP BladeSystem p-Class 3U Power Enclosure in a scalable bus bar configuration or Mini Bus Bar Dual Power Box configuration, connect the load-balancing signal cable between power enclosures. Refer to "Connecting the load-balancing signal cable (on page 50)." c. Connect the bus bars or power bus boxes to the enclosures. Refer to "Installing power distribution devices (on page 33)" and "Installing the power couplers ("Installing the power connectors" on page 38)." 4. If you are using a facility DC power source: a. Connect the grounding cable to the server blade enclosures. Refer to "Connecting facility DC power to the power distribution bus bars (on page 51)." b. Install the facility DC cables. Refer to the documentation that ships with the Facility DC Cable Kit. c. Connect the bus bars or power bus boxes to the enclosures. Refer to "Installing power distribution devices (on page 33)" and "Installing the power couplers ("Installing the power connectors" on page 38)." d. Install the cable bracket. Refer to the documentation that ships with the brackets. 5. Connect to your facility AC or DC power source and power up the system. Refer to the "Powering up the system (on page 59)."

Solution

Power enclosures supported 2 1
Server blade enclosures supported 3 1
Maximum rack space occupied 36U 21U 24U 9U
Scalable bus bar Mini bus bar Mini bus bar* Power bus box
* A Mini Bus Bar Dual Power Box supports two power enclosures attached to the mini bus bar to enable a redundant AC power configuration.
Two mini bus bar configurations, each with one power enclosure and three server blade enclosures, can be installed one above the other to fully populate a 42U rack.
NOTE: Scalable and mini bus bars attach to the rack in the same manner.
Installing a scalable bus bar kit
NOTE: Use the location marks made when you measured the rack with the rack template.
Installing a mini bus bar kit
Installing a power bus box
WARNING: If using facility DC power, cables must be connected by a licensed electrician or trained service personnel familiar with high-power circuitry.
Installing the power connectors
The power connectors are positioned to line up to adjacent server blade enclosures.
Cabling the management modules
The server blade management modules and power management modules are cabled together in daisy-chain fashion to provide the management link. Each management module has two management link connectors: one to connect to enclosures above and one to connect to enclosures below. Cabling the management modules enables the system to identify rack topology for power and data management.
CAUTION: Do not install NIC cabling or telephone cabling into the management link connectors; these devices are not supported.
When deploying the HP BladeSystem 1U Power Enclosure and attached server enclosure into an existing installation, it is necessary to upgrade all management module firmware on all enclosures to the latest version.
Management cabling guidelines
Observe the following guidelines for cabling the management modules.
On the server blade management module: The upper Management Link connects to the upper enclosure. The lower Management Link connects to the lower enclosure. The iLO port connects to the iLO network.
On the power management module: The right management link connector connects to enclosures above the module. The left management link connector connects to enclosures below the module.

Additional guidelines for a 42U solution
Observe the following additional guidelines for configuring a full-rack 42U solution with two pairs of mini bus bars: You must set the power configuration switches to establish the two power zones. Refer to Power configuration switches (on page 72) in this guide. You must cable the power management module in zone 2 (upper pair of mini bus bars) to both adjacent server blade management modules, above and below. This connection enables system management to establish a full-rack topology.
Connecting the management module cables
NOTE: This section applies only to systems that are configured with an enhanced server blade enclosure.
NOTE: Management modules are used only for information management (asset tracking, for example). Disconnecting the management module cabling does not affect system operation.
IMPORTANT: Improper cabling causes all the management link connector LEDs on the management modules to flash.
Be sure the power configuration switches are set properly if you have a full-rack solution with two pairs of mini bus bars. Refer to Power Configuration Switches (on page 72) in this guide.
Connecting the HP BladeSystem p-Class 1U Management Link Cable
IMPORTANT: In installations configured with the HP BladeSystem 1U Power Enclosures and Power Supplies, the power zones are calculated dynamically using the topology information from all the connected enclosures. Disregard the power zone switch and LEDs on the HP BladeSystem 1U Power Enclosure.
If deploying the HP BladeSystem 1U Power Enclosure into a rack installation with other HP BladeSystem Enclosures, the enclosures can be connected to each other with management link cables to identify rack topology. Refer to the "Configuring the dynamic power saver (on page 57)" section in this document.

Connecting to iLO

Cabling the network to the system
Cable the interconnects to the network. Refer to the supporting documentation for specific details on cabling the interconnects.
Connecting the HP BladeSystem p-Class 1U DC power cable to the server blade enclosure
Connecting power cables to a mini bus bar
Connect the power cables to the mini bus bar.
Removing the mini bus bar cover
Connecting power cables to the mini bus bar
NOTE: If you are connecting two HP BladeSystem 3U Power enclosures to mini bus bars, refer to the HP BladeSystem Mini Bus Bar Dual Power Kit Installation Instructions or to the HP BladeSystem p-Class Enclosure Installation Guide.
Replacing the mini bus bar cover

IMPORTANT: Only unlock circuit breakers for couplers that are attached to a server blade enclosure.
9. Be sure that the server blade enclosure DC power LEDs are illuminated green. Refer to "LEDs, buttons, and switches (on page 63)" or to the documentation included with the HP BladeSystem p-Class Server Blade Enclosure.
NOTE: Circuit breakers continue to function in the event of an overload condition even if they are locked. IMPORTANT: Be sure to lock all the circuit breaker switches in the on position. This action prevents anyone from accidentally powering down the system.
Power is now applied to all system hardware.
Powering up the system (facility DC)
If you are using a facility DC power source: 1. Connect the power cables to the DC power source. 2. Apply power to the facility power connection, if necessary.
3. Unlock the circuit breaker switches on the bus bars or power bus boxes and toggle the switches to the on position. This action applies DC power to the server blade enclosures.
IMPORTANT: Be sure to lock all the circuit breaker switches in the on position. This action prevents anyone from accidentally powering down the system. NOTE: Circuit breakers continue to function in the event of an overload condition even if they are locked.
4. Be sure that the server blade enclosure DC power LEDs are illuminated green. Refer to "LEDs, buttons, and switches (on page 63)" or to the documentation included with the HP BladeSystem p-Class Server Blade Enclosure. Power is now applied to all system hardware.
Completing the installation
To complete the BladeSystem installation, perform the following tasks: Build the management environment. Name the server blade enclosures. Name the server blade components. Update the component firmware. Install operating systems on the server blades. Deploy application software onto the server blades. Establish the SAN environment (optional).
For more information, refer to the HP Remote Insight Lights-Out Edition User Guide, the HP Remote Insight Lights-Out Edition II User Guide, or the HP Integrated Lights-Out User Guide available at the Remote Management website (http://www.hp.com/servers/lights-out).
In this section LEDs.....63 Buttons and switches....71
The system contains several sets of LEDs that indicate the status and settings of hardware components. Use the following sections to determine the location and functions of LEDs on system components. For information about LEDs on server blades, interconnect modules, hard drives, and other devices, refer to the documentation supplied with each device.

Server blade enclosure LEDs
The server blade enclosure has two LEDs that provide the status of DC power input. Use the following figure and table to identify LED locations and functions.

Item 1

LED Description Bus B power
Status Off = No power available Green = Power available Red = Polarity reversed

Bus A power

Off = No power available Green = Power available Red = Polarity reversed
Server blade management module LEDs
The server blade management module has LEDs for identification, power status, and management activity. Use the following figure and table to identify LED locations and functions.
LED Description Fault status LED
Status Red = Fault process activity Off = No fault process activity

Item 2

LED Description Unit identification
Status Blue = Identified Off = No active remote management

Power LED

Off = No power Green = Management module is powered up

Power configuration

Off/Green = Power zone 1 (default) Green/Green = Power zone 2 (secondary)
Management link activity LED Management link LED
Amber = Activity* Off = No link or activity Green = Network linked* Off = No link

iLO activity

Green = Activity Off = No activity

iLO Link

Green = Network linked Off = No link
* All management link connector LEDs flash on the server blade management modules and power management modules when management modules are cabled improperly.
Power management module LEDs
The power management module has LEDs for identification, power status, and management activity.
IMPORTANT: If the power configuration switch is set improperly, all power management module management link connector LEDs flash. IMPORTANT: If management modules are cabled improperly, all management link connector LEDs flash on all management modules.
Use the following figure and table to identify LED locations and functions.
LED Description Management link activity LED Management link LED
Status Amber = Network activity* Off = No link or activity Green = Network linked* Off = No link

Fault status LED

Red = Fault process activity Off = No fault process activity

To set the switches for multiple power zones, use the following example and figure. Example: A full-rack 42U solution with two pairs of mini bus bars requires two power zones. To distinguish the two power zones, set all the power configuration switches on management modules in the upper zone (zone 2) to the up position; the power configuration switches on the management modules in the lower zone (zone 1) remain in the down (default) position.
Item Power zone 2 Zone 2 switches in the up (secondary) position Power zone 1 Zone 1 switches in the down (default) position
In this section Troubleshooting resources...77 Important safety information....77
Troubleshooting resources
NOTE: For common troubleshooting procedures, the term "server" is used to mean servers and server blades.
The HP ProLiant Servers Troubleshooting Guide provides simple procedures for resolving common problems as well as a comprehensive course of action for fault isolation and identification, error message interpretation, issue resolution, and software maintenance. To obtain the guide, refer to any of the following sources and then select the HP ProLiant Servers Troubleshooting Guide. The server-specific Documentation CD The Business Support Center on the HP website (http://www.hp.com/support). You can find the guide by using the navigation features on the HP website. The Technical Documentation website (http://www.docs.hp.com). Select Enterprise Servers, Workstations and Systems Hardware, and then the appropriate server.
Important safety information
Familiarize yourself with the safety information in the following sections before troubleshooting the server.
Before servicing this product, read the Important Safety Information document provided with the server.

Symbols on equipment

The following symbols may be placed on equipment to indicate the presence of potentially hazardous conditions.
This symbol indicates the presence of hazardous energy circuits or electric shock hazards. Refer all servicing to qualified personnel. WARNING: To reduce the risk of injury from electric shock hazards, do not open this enclosure. Refer all maintenance, upgrades, and servicing to qualified personnel.
This symbol indicates the presence of electric shock hazards. The area contains no user or field serviceable parts. Do not open for any reason. WARNING: To reduce the risk of injury from electric shock hazards, do not open this enclosure.
This symbol on an RJ-45 receptacle indicates a network interface connection. WARNING: To reduce the risk of electric shock, fire, or damage to the equipment, do not plug telephone or telecommunications connectors into this receptacle.

CAUTION: To properly ventilate the system, you must provide at least 7.6 cm (3.0 in) of clearance at the front and back of the server.
CAUTION: The server is designed to be electrically grounded (earthed). To ensure proper operation, plug the AC power cord into a properly grounded AC outlet only.
In this section Regulatory compliance identification numbers...83 Federal Communications Commission notice...84 Declaration of conformity for products marked with the FCC logo, United States only.85 Modifications.....86 Cables....86 Canadian notice (Avis Canadien)....86 European Union regulatory notice...87 Japanese notice.....88 Power cord statement for Japan....88 BSMI notice.....88 Korean notice A&B.....89 Laser compliance....89 Battery replacement notice....90 Taiwan battery recycling notice....91
Regulatory compliance identification numbers
For the purpose of regulatory compliance certifications and identification, this product has been assigned a unique regulatory model number. The regulatory model number can be found on the product nameplate label, along with all required approval markings and information. When requesting compliance information for this product, always refer to this regulatory model number. The regulatory model number is not the marketing name or model number of the product.
Federal Communications Commission notice
Part 15 of the Federal Communications Commission (FCC) Rules and Regulations has established Radio Frequency (RF) emission limits to provide an interference-free radio frequency spectrum. Many electronic devices, including computers, generate RF energy incidental to their intended function and are, therefore, covered by these rules. These rules place computers and related peripheral devices into two classes, A and B, depending upon their intended installation. Class A devices are those that may reasonably be expected to be installed in a business or commercial environment. Class B devices are those that may reasonably be expected to be installed in a residential environment (for example, personal computers). The FCC requires devices in both classes to bear a label indicating the interference potential of the device as well as additional operating instructions for the user.

FCC rating label

The FCC rating label on the device shows the classification (A or B) of the equipment. Class B devices have an FCC logo or ID on the label. Class A devices do not have an FCC logo or ID on the label. After you determine the class of the device, refer to the corresponding statement.

Class A equipment

Battery replacement notice
WARNING: The computer contains an internal lithium manganese dioxide, a vanadium pentoxide, or an alkaline battery pack. A risk of fire and burns exists if the battery pack is not properly handled. To reduce the risk of personal injury: Do not attempt to recharge the battery. Do not expose the battery to temperatures higher than 60C (140F). Do not disassemble, crush, puncture, short external contacts, or dispose of in fire or water. Batteries, battery packs, and accumulators should not be disposed of together with the general household waste. To forward them to recycling or proper disposal, please use the public collection system or return them to HP, an authorized HP Partner, or their agents.
For more information about battery replacement or proper disposal, contact an authorized reseller or an authorized service provider.
Taiwan battery recycling notice
The Taiwan EPA requires dry battery manufacturing or importing firms in accordance with Article 15 of the Waste Disposal Act to indicate the recovery marks on the batteries used in sales, giveaway or promotion. Contact a qualified Taiwanese recycler for proper battery disposal.
In this section Preventing electrostatic discharge...93 Grounding methods to prevent electrostatic discharge...94
Preventing electrostatic discharge
To prevent damaging the system, be aware of the precautions you need to follow when setting up the system or handling parts. A discharge of static electricity from a finger or other conductor may damage system boards or other staticsensitive devices. This type of damage may reduce the life expectancy of the device. To prevent electrostatic damage: Avoid hand contact by transporting and storing products in static-safe containers. Keep electrostatic-sensitive parts in their containers until they arrive at staticfree workstations. Place parts on a grounded surface before removing them from their containers. Avoid touching pins, leads, or circuitry. Always be properly grounded when touching a static-sensitive component or assembly.
Grounding methods to prevent electrostatic discharge
Several methods are used for grounding. Use one or more of the following methods when handling or installing electrostatic-sensitive parts: Use a wrist strap connected by a ground cord to a grounded workstation or computer chassis. Wrist straps are flexible straps with a minimum of 1 megohm 10 percent resistance in the ground cords. To provide proper ground, wear the strap snug against the skin. Use heel straps, toe straps, or boot straps at standing workstations. Wear the straps on both feet when standing on conductive floors or dissipating floor mats. Use conductive field service tools. Use a portable field service kit with a folding static-dissipating work mat.

If you do not have any of the suggested equipment for proper grounding, have an authorized reseller install the part. For more information on static electricity or assistance with product installation, contact an authorized reseller.
In this section Before you contact HP....95 HP contact information.....95

Before you contact HP

Be sure to have the following information available before you call HP: Technical support registration number (if applicable) Product serial number Product model name and number Applicable error messages Add-on boards or hardware Third-party hardware or software Operating system type and revision level

HP contact information

For the name of the nearest HP authorized reseller: In the United States, call 1-800-345-1518. In Canada, call 1-800-263-5868. In other locations, refer to the HP website (http://www.hp.com).
For HP technical support: In North America:
Call 1-800-HP-INVENT (1-800-474-6836). This service is available 24 hours a day, 7 days a week. For continuous quality improvement, calls may be recorded or monitored. If you have purchased a Care Pack (service upgrade), call 1-800-6333600. For more information about Care Packs, refer to the HP website (http://www.hp.com). Outside North America, call the nearest HP Technical Support Phone Center. For telephone numbers for worldwide Technical Support Centers, refer to the HP website (http://www.hp.com).
Acronyms and abbreviations
ACU Array Configuration Utility BBWC battery-backed write cache BIOS Basic Input/Output System BOOTP Bootstrap Protocol TCP/IP Transmission Control Protocol/Internet Protocol ConRep Configuration Replication utility CPU central processing unit DHCP Dynamic Host Configuration Protocol
DIMM dual inline memory module DMA direct memory access ECC error checking and correcting EEPROM electrical erasable programmable read only memory ESD electrostatic discharge EULA end user license agreement FC Fibre Channel GBIC Gigabit Interface Converter HBA host bus adapter IEC International Electrotechnical Commission

The HP BladeSystem p-Class 1U power enclosure: hot-plug, redundant power for a server blade enclosure

technology brief

Abstract..... 3 Introduction..... 3 Components of the enclosure.... 3 Hot-plug, redundant power supplies.... 3 Redundant AC power.... 4 Hot-plug power management module.... 5 Features of the enclosure..... 5 Bi-directional electronic e-fuse... 5 Power zones.... 5 Firmware in mixed environments.... 6 Dynamic power saver.... 7 Redundancy with dynamic power saver... 7 Enabling dynamic power saver.... 8 Serial port..... 8 Remote access to the serial port.... 10 Efficient cabling..... 10 Management link cable.... 11 Power distribution unit cables... 11 Infrastructure configurations.... 12 Using PDUs with the 1U power enclosure... 13 Redundancy.... 13 Maximum rated VA capacity... 13 Number of PDU outlets.... 13 Three-phase input.... 13 Dynamic power saver and three-phase input PDUs... 13 Standard configurations.... 15 Using ProLiant BL35p server blades.... 15 Using ProLiant BL30p server blades.... 16 Using ProLiant BL20p server blades.... 17 Risks associated with extreme density.... 18 Supported configurations for the S348 Monitored PDU and S332 Monitored PDU.. 18 North America/Japan..... 18 International.... 18 Supported configurations for the 40 A PDU.... 18 47U rack..... 19 800-mm-wide 42U rack.... 19 Standard 42U rack.... 20 Using uninterruptible power supplies (UPS) with the 1U power enclosure... 20 Conclusion..... 21 For more information.... 22

Call to action.... 22

Abstract
The HP BladeSystem p-Class1U power enclosure provides hot-plug, redundant power for a single enclosure of HP ProLiant BL p-Class server blades from standard single-phase AC inputs. A properly configured HP BladeSystem p-Class 1U power enclosure is an ideal power solution for small office and remote site blade deployments. This technology brief explains the 1U power enclosure operation and features as well as infrastructure configuration considerations. This paper is written with the assumption that readers are already familiar with the HP BladeSystem.

Introduction

The HP BladeSystem consists of modular components that enable IT administrators to readily modify and scale their infrastructures to meet changing IT demands. The ability to provide required power to servers and use it efficiently is a critical IT need. The HP BladeSystem includes two power subsystem options: a 3U power subsystem and a 1U power subsystem. This paper describes the 1U power subsystem only. Refer to www.hp.com/go/bladesystem for information about the 3U power subsystem. The 1U power subsystem includes an HP BladeSystem p-Class 1U power enclosure configured with embedded power supplies and a power management module. Power supply and AC line cord redundancy is provided when powering one fully configured HP BladeSystem p-Class server blade enclosure. The power management module enables IT administrators to efficiently monitor and manage total enclosure power consumption. Choosing an optimal power solution requires the consideration of many factors, including the number of server enclosures needed, the type of server blades to be installed, and the type of available power. The HP BladeSystem p-Class 1U power enclosure is particularly well suited to the following IT environments: Small or mid-size businesses using server blades in their infrastructure Remote or branch offices with distributed server blade deployments IT environments with single-phase power requirements
Components of the enclosure
The HP BladeSystem 1U power enclosure supports high availability by providing hot-plug, redundant power supplies; redundant AC inputs; and a hot-plug power management module that operates independently of the server blades and interconnects.
Hot-plug, redundant power supplies
The 1U power enclosure houses up to six hot-plug power supplies, each unit rated at 2,000 W DC output power. The enclosed six power supply bays are divided into two sides with three bays on bus A and three bays on bus B (Figure 1 and Table 1).
Figure 1. HP BladeSystem p-Class 1U power enclosure bays
Table 1. HP BladeSystem p-Class 1U power enclosure bay descriptions Item Description Power supply bay 1 Power supply bay 2 Power supply bay 3 Power supply bay 4 Power supply bay 5 Power supply bay 6 Configuration Bus A Bus A Bus A Bus B Bus B Bus B
To implement a redundant configuration using power supplies in the 1U power enclosure, one or more of bays 1 through 3 and an equal number of bays 4 through 6 must be populated with a power supply.

Redundant AC power

For redundant AC power, bays 1 through 3 must be supplied with AC power from a different branch circuit than bays 4 through 6. Each bay must be supplied with single-phase AC power according to the specifications in the QuickSpecs, which are located at http://h18004.www1.hp.com/products/quickspecs/12330_div/12330_div.html. The branch circuit should have adequate capacity to handle the peak current demands of a fully populated 1U power enclosure when attached to a fully populated server blade enclosure. If only one side of the power enclosure is populated with power supplies, the power subsystem is not redundant. If AC redundancy is not required, three power supplies located in any three bays can provide adequate power for a fully loaded server blade enclosure.

Hot-plug power management module
The hot-plug power management module monitors the power subsystem components and regulates the power-up sequence of newly installed server blades and interconnect switches. The power management module is connected with cables to the server blade enclosure management module(s) to facilitate communication of management information, such as server blade and interconnect location, power supply budget, and health status.
Features of the enclosure
The HP BladeSystem p-Class 1U power enclosure provides for power subsystem management with the following features: Bi-directional electronic e-fuse provides prompt power up. Power zones provide communication and management capabilities between power enclosures and supported server blade enclosures. Dynamic power saver achieves efficient power consumption. Serial port allows direct monitoring of the 1U power enclosure status. Efficient cabling reduces clutter in the area behind the 1U power enclosure.
Bi-directional electronic e-fuse
The 1U power enclosure has a bi-directional electronic e-fuse switch that connects the -48-V DC outputs on bus A to the -48-V DC outputs on bus B. Once a single power supply is installed in a bay on either side of the 1U power enclosure, that side of the power enclosure is immediately powered. Approximately 3 seconds later, the internal electronic e-fuse switch automatically closes, and the other side of the 1U power enclosure is powered as a result. In short, both sides of the 1U power enclosure are powered even if only one power supply is installed, and the 1U power enclosure can operate this way indefinitely. With only one power supply installed, the built-in power management software attempts to limit the number of blade servers allowed to power on. An administrator, however, can override the warning and manually power up the servers. The only time the electronic switch in the HP BladeSystem p-Class 1U power enclosure opens is when there is a bus short in the power enclosure. If a bus short occurs in the power enclosure, the electronic e-fuse switch quickly separates bus A from bus B. The circuitry within the 1U power enclosure automatically and continuously monitors the faulted side. Once the fault is cleared, the electronic efuse switch resets and closes automatically restoring full power to both sides of the server blade enclosure. This is a rare situation.

Power zones

Power zones, when set properly, associate server blade enclosures with the power enclosure(s) that support them. This allows power information and alerts to be sent to the proper power management module or server blade management module when power conditions change. For example, if an administrator removes a power supply from the HP BladeSystem p-Class 1U power enclosure, notification is sent to the affected server blade enclosure in that power zone. Power zones also define the startup sequence of the server blades when the entire rack needs to be restarted after a total power outage. The server blade enclosures communicate with the power enclosures in the rack to ensure that the server blades and enclosures are powered in sequence, rather than all at once, to prevent overloading the AC infrastructure. The sequence always runs from the top of the rack (power zone 6), top left-hand blade through the top and bottom row of the blades in that enclosure (if ProLiant BL30p or BL35p server blades are installed). The sequence then proceeds

down to the next enclosure and continues until the bottom right blade in the bottom server blade enclosure is powered. In a rack that contains many server blade enclosures, the sequencing process may cause a significant time delay before the last server blade is powered. However, this is preferable to the alternativethe possibility that the main breakers trip due to the excessive load on the AC infrastructure as all the server blade enclosures try to power simultaneously. Firmware in mixed environments When 1U power enclosures and 3U power enclosures are used in the same rack, the firmware must be upgraded to the latest version for correct power zone operation. As of firmware release 2.20, there are important changes in how power zones are managed. In firmware releases prior to 2.20, there were only two power zones (zone 1 and 2) that were set by a switch on the rear of 3U power enclosures. Firmware 2.20 provides the capability to have up to six power zones, based on the absolute maximum hardware that could fit into one rack. The power zone switch on the rear of the 3U power enclosure only has a setting for zone 1 and 2; new power zones start at 3 to avoid overlap with existing power zones. The primary difference in setting the new power zones is that they are not set by a switch on the power enclosure. The switch is still present on HP BladeSystem p-Class 3U power enclosures for legacy firmware, but firmware version 2.20 and above do not use the switch. The new power zones (3 and above) are set automatically by the firmware based on rack topology. Unlike the 3U power enclosure, the 1U power enclosure does not have a power zone switch because it was released with firmware 2.20. Every power zone must include a power source (either the 1U power enclosure or the 3U power enclosure) and at least one server blade enclosure. In the pre-2.20 firmware environment, if a server blade enclosure were in zone 2 and the power enclosure supporting it were in zone 1, the server blades and switches in that sever blade enclosure would never power on automatically because the devices in the server blade enclosure must request power from a power source in their own zone in order to power on. If the power source is not in the same zone as the server blade enclosure, the request for power is not answered because power is not available in that zone. To ensure that all power enclosures and server blade enclosures are configured in the proper zone, all enclosures in a rack should be upgraded to firmware 2.20. If one enclosure in an infrastructure is upgraded to firmware 2.20 and the other enclosures are not upgraded: The enclosure upgraded to 2.20 is put into power zone 3. The enclosures not upgraded are placed in power zone 1 or 2 (depending on the zone in which the physical switch is set). Once all the enclosures in a rack are upgraded to firmware 2.20, the switch setting on the rear of the enclosure no longer serves a functional purpose. After an upgrade to firmware 2.20, power zone 1 and 2 are no longer used since the power zones are set automatically by the firmware based on rack topology, not switch settings. HP does not support mixed firmware versions within the same infrastructure. All enclosures should have the same firmware version.

Dynamic power saver

The dynamic power saver feature in the HP BladeSystem p-Class 1U power enclosure provides for efficient use of power in the server blade enclosure. When this feature is enabled, total power consumption is monitored in real time. Power supplies are placed in a standby condition when the power demand from the server blade enclosure is low. As power demand increases, the standby power supplies activate as necessary to deliver the required power. This enables the power enclosure to operate at optimum efficiency. Optimum efficiency can be achieved because of the power supply efficiency curve associated with any power supply. Power supply efficiency is simply a measure of power in versus power out, so at 50 percent efficiency 2,000 W in would equal 1,000 W out. The difference is wasted energy, which costs money. Dynamic power saver recognizes that most power supplies operate less efficiently when lightly loaded and more efficiently when heavily loaded. A power supply installed in the 1U power enclosure running with a 10 percent load could have efficiency as low as 50 percent, but with a 50 percent load, efficiency increases to over 90 percent, providing a significant savings in power consumption. Dynamic power saver drives power supply efficiency by shifting the load so there is a heavier load on fewer power supplies as opposed to a lighter load on all the installed power supplies. Redundancy with dynamic power saver Redundant power is maintained in dynamic power saver mode. The 1U power enclosure ensures that at least two power supplies, one from bus A and one from bus B, are active. When dynamic power saver is enabled on a 1U power enclosure with six power supplies installed, a low load initiates the following sequence:

1. 2. 3. 4.

Initially all power supplies are powered as normal. Power supplies installed in bay 3 and bay 6 are placed in standby. Power supplies installed in bay 2 and bay 5 are placed in standby. Power supplies installed in bay 1 and bay 4 are always powered at 50 percent load or less to ensure redundancy.
The reverse sequence applies as the load increases. Power supplies that are on standby are activated in pairs and the load is shared so the maximum load on each feed is 50 percent. Equal distribution of the load ensures that redundancy is always maintained.
Enabling dynamic power saver To configure the dynamic power saver, the power management module must be removed from the 1U power enclosure and the dynamic power saver feature must be enabled. The module is hot pluggable and can safely be removed during normal server operation (Figure 2). After enabling the dynamic power saver, reinstall the power management module.

Figure 2. The 1U power enclosure power management module and location of the dynamic power saver switches
Table 2. Dynamic power saver switch positions and functions Position 3 Function Dynamic power saver disabled (default) Dynamic power saver enabled Reserved (off = default)

Serial port

The serial port on the back of the HP BladeSystem p-Class 1U power enclosure provides a way for IT administrators to directly monitor the status of the 1U power enclosure. As shown in Figure 3 and explained in Table 3, detailed information can be obtained through the serial port.
Table 3. Status information displayed through the serial port Status information Uptime Power supply location (slot number), status, power usage, input/output temperature Enclosure backplane temperature Number of fault conditions Status of unit identification (UID) LED Status of enclosure link Management module firmware version Description Shows the amount of time the system has been powered on. Provides the physical location of power supplies, their fault status, power usage, and operating temperatures. Displays the temperature on the enclosure backplane. Shows the number of unresolved faults in the system. Specifies whether UID LED is active or not. Provides information as to whether the link is connected or not (the enclosure link connects to the blade enclosure). Shows revision of the management firmware.
Status information Overall power usage Power supply redundancy (enclosure N+1 redundancy) AC feed redundancy Bus balancing
Description Tabulates total power usage of all the power supplies in the enclosure. Indicates whether there are sufficient power supplies to take over the load in the event that one power supply failed without causing an enclosure power failure. Specifies whether sufficient power supplies are installed for the enclosure to remain powered on if an AC feed is lost. Ensures that the load is balance across the Bus A and Bus B feeds. Only applies to original p-Class enclosure.
Figure 3. Serial port display
A null modem cable can be used to connect the serial port to a terminal. Terminal software, such as Microsoft Windows HyperTerminal or Minicom for Linux, can be used to access the 1U power enclosure status display. On the terminal, configure the following settings to allow communication through the serial port: 9,600 bps No parity 8 data bits 1 stop bit Software flow control, may also be called XON/XOFF VT100 terminal emulation
The serial port on the HP BladeSystem p-Class 1U power enclosure does not support hardware flow control settings. Remote access to the serial port IT administrators can enable remote access to the serial port in two different ways:

1. Through the HP Serial Console Servers software, which allows serial devices to be accessed 2. Through the HP IP Console with the Serial Interface Adapter.
remotely through an IP network, or
NOTE: HP Serial Console Servers and HP IT Console with Serial Interface Adapter can also be used for remote access to other devices with a serial port. For additional information about HP Serial Console Servers and HP Serial Interface Adapter: www.hp.com/go/kvm.

Efficient cabling

The HP BladeSystem p-Class 1U power enclosure uses a well-organized cabling system to connect to the server blade enclosure and any attached Power Distribution Units (PDUs). The 1U power enclosure provides a direct power connection to the server blade enclosure through two dedicated DC power cables (Figure 4).
Figure 4. The 1U power enclosure power cables connected to the server blade enclosure
Each server blade enclosure is rated to support up to 6,000 W (3,000 W per side and thus 3,000 W per cable). The individual DC power cables are sized to support the worst-case power tolerances. At the lowest possible power supply voltage of -48.8 V, the maximum rated sustained output current would be 61.5 A per side and per cable.
Management link cable To provide two-way communication, connect a management link cable from the power management module of the 1U power enclosure to the server blade enclosure (Figure 5).
Figure 5. Management link cable connected from the 1U power enclosure power management module to the server blade enclosure
Power distribution unit cables If PDUs are being used, they must be connected to the 1U power enclosure in three steps. First, before connecting any PDU power cables, turn off or disconnect facility AC power from the PDUs. Secondly, connect the PDU power cables to the AC power input connectors on the 1U power enclosure (see Figure 6). Lastly, once the PDU power cables are connected to the PDUs, power to the PDUs can be restored.
Figure 6. PDU power cables connected to the 1U power enclosure
Infrastructure configurations
When using the HP BladeSystem p-Class 1U power enclosure, follow the general guidelines in Table 4 to install the proper amount of power supplies.
Table 4. General guidelines for power supply installation in the 1U power enclosure Infrastructure Required power supplies installed in 1U power enclosure Server blade enclosure populated with ProLiant BL20p, BL25p, or BL35p server blades Server blade enclosure populated with ProLiant BL35p dual-core server blades Server blade enclosure populated with ProLiant BL30p server blades More than 3,000 W required per enclosure More than 4,000 W required per enclosure 6

To determine power requirements for an enclosure, use the HP Power Calculator available at www.hp.com/go/bladesystem/powercalculator. The HP BladeSystem p-Class sizing utility is a Microsoft Excel workbook with a power calculator; it can be used to help determine the correct modular components for specific IT environments.
Figure 7. The HP BladeSystem p-Class Sizing utility
Using PDUs with the 1U power enclosure
When using PDUs within an HP BladeSystem environment, key considerations include redundancy, volt-ampere (VA) capacity of the PDU, number of PDU outlets, and using PDUs with single-phase or three-phase inputs. Redundancy Planners must consider redundancy when determining how to distribute power using PDUs. The normal method of delivering AC redundancy is to use two separate feeds to each side of the 1U power enclosure, referred to as the A feed and the B feed. To ensure that the power subsystem remains redundant in the event of an AC line feed failure, both feeds and the associated PDUs must be sized to take the full load of the attached 1U power enclosures. Maximum rated VA capacity The key variable to consider when using PDUs with the 1U power enclosure is the maximum rated VA load capacity for the PDU. The HP Power Calculator allows the calculation of the input VA requirements of the 1U power enclosure to support any given server blade configuration. Once the total input VA rating requirement for the 1U power enclosure is obtained, compare this to the rated load capacity of available PDUs to determine how many 1U power enclosures can be supported. Number of PDU outlets Planners must also factor in the number of outlets available on the PDU. For example, the HP 40A NA PDU (252633-B4) has a maximum capacity of 9,200 VA. Theoretically, in a redundant configuration, three full server blade enclosures populated with ProLiant BL30p server blades (with 3.06 GHz processors) rated at 5,300 VA, could be connected to four of these PDUs. However, each PDU has only four outlets while each enclosure requires six connections at 5,300VA; resulting in 16 available outlets to accommodate 18 required connectionsan impossible configuration. Three-phase input Planners should consider whether using a three-phase input PDU is a viable option. Three-phase PDUs take standard three-phase power input feeds and convert the power to standard single-phase outputs to power industry-standard IT equipment. One advantage of using three-phase PDUs is that more power can be delivered to a rack with fewer power drops. For example, at 208 V a 30 A singlephase circuit delivers 4,992 VA, while a three-phase circuit delivers 8,640 VA. Also, when comparing similar power levels, the size for the wiring and connectors is significantly smaller with three-phase power. Phase balance is an important consideration when working with three-phase power. For optimum efficiency, the load attached to a three-phase source should be balanced across all three phases. It is possible to balance the load by simply installing six power supplies in the 1U power enclosure; however, this may not lead to the most efficient use of PDU outlets or power. Manually balancing the load by plugging in power supplies across phases when using a three-phase PDU may provide for a more efficient usage of outlets and power. Dynamic power saver and three-phase input PDUs Dynamic power saver also affects the phase loads on a three-phase input PDU. The key is to ensure that the load is balanced as well as possible across all three phases. The determined sequence in which the power supplies are placed into standby should prevent any single phase from being excessively loaded. When dynamic power saver is enabled, power supplies one and four are always powered; power supplies two and five are powered next; and power supplies three and six are powered last. In a rack with multiple 1U power enclosures, the power supplies installed in bay 1 in each of the 1U power enclosures should not be plugged into the same phase. Each installed power supply in bay 1 should be connected to a different phase on the PDU.

Power supplies installed in bay 2 in each of the 1U power enclosures should also be connected to a different phase on the PDU. Figure 8 illustrates how 1U power enclosures should be connected with four power supplies installed.
NOTE: The grayscale outlets on the PDU in Figure 8 indicate which phase the outlet is attached to. The wires are color coded to distinguish the connections to power supplies installed in bus A and bus B. Power supplies are numbered in reverse because the view is from the rear of the 1U power enclosure.
Figure 8. HP BladeSystem p-Class 1U power enclosures connections (rear view)
4 Phase 1 Phase 2 Phase 3

Standard configurations

The following configurations review some common usage scenarios for the HP BladeSystem p-Class 1U power enclosure, including the type of server blades populated and PDU options. Using ProLiant BL35p server blades In this configuration, the rack contains three enhanced server blade enclosures, three 1U power enclosures, and six PDUs (Figure 9). Each enhanced server blade enclosure is populated with ProLiant BL35p server blades and supported by a 1U power enclosure with four power supplies installed. The 1U power enclosures are attached to two 24 A modular PDUs. The ProLiant BL35p server blades have two single-core 2.4-GHz processors with 1 MB L2 cache, 4 GB of RAM, and one 60-GB hard drive, resulting in 4,270 VA input. Four power supplies are needed in the 1U power enclosures for redundant power. The 24 A modular PDU used in this configuration has a load capacity of 4,992 VA, so it can support one server blade enclosure populated with ProLiant BL35p server blades.
Figure 9. Rack with enhanced server blade enclosures populated with ProLiant BL30p server blades, three 1U power enclosures and six 24 A modular PDUs
Using ProLiant BL30p server blades In this configuration the rack contains four enhanced server blade enclosures, four 1U power enclosures and six PDUs (Figure 10). Each enhanced server blade enclosure is populated with ProLiant BL30p server blades and has a 1U power enclosure with six power supplies installed. The 1U power enclosures are connected to two 40 A modular PDUs. The ProLiant BL30p server blades have two single-core 3.2-GHz processors with 2 MB L3 cache, 4 GB of RAM, and one 60-GB hard drive, resulting in 5,768 VA input. Six power supplies are needed in the 1U power enclosures for redundant power. The 40 A modular PDU has a load capacity of 8,320 VA, so it can support one server blade enclosure fully populated with ProLiant BL30p server blades, with 2,552 VA extra capacity. Each power supply has a load of 1,923 VA; an extra power supply unit can be connected to each PDU and cross-wired, as shown in Figure 10.
Figure 10. Proposed configuration using four enhanced server blade enclosures populated with ProLiant BL30p server blades, four 1U power enclosures and six 40 A modular PDUs

Using ProLiant BL20p server blades In this configuration, the rack contains six enhanced server blade enclosures, six 1U power enclosures, and six PDUs. Each enhanced server blade enclosure is populated with ProLiant BL20p server blades and has a 1U power enclosure with four power supplies installed. The 1U power enclosures are connected to two 40 A modular PDUs. The ProLiant BL20p server blades have a single-core 3.6-GHz processor with 2 MB L2 cache, 4 GB of RAM, and two 18-GB 15,000 RPM SCSI hard drives, resulting in 3,714 VA input. Four power supplies are needed in the 1U power enclosure for redundant power. The 40 A modular PDU has a load capacity of 8,320 VA, so it can support two server blade enclosures fully populated with ProLiant BL20p server blades.
Figure 11. Proposed configuration using six enhanced server blade enclosures populated with ProLiant BL20p server blades, six 1U power enclosures and six 40 A modular PDUs
Risks associated with extreme density
While it is possible to build a fully populated a rack with server blades and retain power supply and line cord redundancy using HP BladeSystem p-Class 1U power enclosures, several items should be considered prior to implementation. The primary issues associated with extreme density that must be seriously considered include: heat, weight, PDU placement and PDU breaker and line cord access after the rack is built. Before deploying these configurations, consider the heat load placed on the data center air-conditioning system and the weight load placed on the floor. There are two methods of properly implementing a rack with six 1U power enclosures installed.
1. Install six 40 A modular PDUs in the rack. This PDU setup provides power for up to six 1U power
enclosures, with a maximum of four power supplies in each enclosure. It provides sufficient power for all ProLiant BL20/25p configurations, ProLiant BL40/45p configurations, and the majority of ProLiant BL35p configurations. The ProLiant BL30p configuration requires six power supplies per power enclosure. Some of the dual-core ProLiant BL35p configurations may require six power supplies, which can risk overloading the PDUs.
2. Use the HP S348 Monitored PDU or S332 Monitored PDU.
NOTE: International configurations can be assembled using the 32 A modular PDU. This PDU has slightly less power capacity (7,680 VA versus the 8,320 VA) than the 40 A modular PDU. Always check the power calculators.
Supported configurations for the S348 Monitored PDU and S332 Monitored PDU
The S348 and S332 PDUs mount in the rear of the rack so there are no issues with access to breakers or line cords. However, access can be enhanced using a rear extension kit, which adds an extra 155 mm or 6 inches of depth to the rear of the rack. The addition of the rack light kit can also significantly increase ease of use and access. North America/Japan Install four HP 17.3 kVA S348 Monitored PDUs. This provides 24 -four C19 outlets and 34.6 kVA of power and supports up to six 1U power enclosures of 5.7 kVA each. For 1U power enclosures of 2.8 kVA or less, two S348 Monitored PDUs are sufficient. International Install four S332 Monitored PDUs. This provides 42 kVA of power and can support six 1U power enclosures of any configuration. For 1U power enclosures of 3.52 kVA or less, two S332 Monitored PDUs are sufficient.

Supported configurations for the 40 A PDU
The 40 A PDUs can be mounted in a 1U configuration, which is recommended for best access, or in the "0U" space in the side of the rack, which may provide restricted access to the PDU breakers. The following configurations are potential solutions to provide power for six server blade enclosures powered by six 1U power enclosures and a 40 A PDU.
47U rack Mounting the PDUs in the 1U configuration requires an additional 3U of vertical space in the rack. Three PDUs must be mounted facing the front of the rack and three PDUs must be mounted facing the back of the rack (Figure 12). This provides 42U of vertical space for the servers and power enclosures and 3U additional space for the PDU mounting. This configuration must be assembled onsite, as it is not available through Factory Express.
Figure 12. Partial diagram of front and back mounted PDUs
800-mm-wide 42U rack The 800-mm-wide rack ships standard with vertical blanking panels that block air recirculation back to the front of the rack. Each side of the rack provides 100mm (approximately 4 inches) of space on either side of the rack for access to the 0U space. Access to the PDUs from the front of the rack can be gained by removing the three screws that secure the vertical blanking panels. This configuration must be assembled onsite, as it is not available through Factory Express.
Standard 42U rack This configuration, while possible, may cause issues because of the limited access to the PDUs in the 0U space after all the servers are installed. HP recommends mounting the modular PDU in the 1U configuration for best access to breaker actuators and receptacles. Otherwise, in the event of a failure, access to the PDU breakers requires the removal of server blade and power enclosures from the rack. This configuration is only recommended in these situations: The rack is a stand-alone unit and there is clear access to both sides of the rack by simply removing side panels. There is sufficient space on each side of the rack to provide access to the PDUs for breaker and receptacle access. The rack can be rolled forward away from the row to allow side access to the PDUs.
NOTE: For more information on the PDUs discussed in this section, visit: http://h18004.www1.hp.com/products/servers/proliantstorage/ power-protection/power-distribution/index.html
Using uninterruptible power supplies (UPS) with the 1U power enclosure
The key factor to consider when sizing a UPS is the supported output wattage for the UPS. The UPS output wattage must be matched to the total input wattage of the supported 1U power enclosure. When connecting a UPS it is important to remember that VA and W are not the same. The HP R5500XR UPS provides the highest level of availability when used with the 1U power enclosure. In a single-feed environment (Figure 13, top left), the R5500XR can support a single 1U power enclosure with up to four installed power supplies. This setup can be used to protect the system from unstable power lines and provide a limited amount of backup time for orderly shut down in the event of AC failure. A dual-feed, single-protection setup (Figure 13, top right) can be used to provide an extra level of availability. If the AC fails and the PDU side has no power, the full load shifts to UPS power to allow for a controlled shutdown. UPS software can also be used to perform a controlled shutdown. Using this configuration, a potential problem can occur in the event of a cascading failure where the UPS side fails first. If the AC power fails, the UPS handles the load on its side, which begins to discharge the UPS. If the PDU side fails, the whole system can potentially fail without initiating a controlled shutdown because of the power drain on the UPS. The ultimate level of availability and protection is provided by the dual-feed, dual-protection configuration (Figure 13, bottom). This configuration always provides for an orderly shutdown when a complete loss of utility power occurs.

Figure 13. AC feed redundancy using the HP R5500XR UPS Single-feed, single protection Dual feed,-single protection
Dual-feed, dual-protection

Conclusion

The HP BladeSystem p-Class 1U power enclosure is a vital component of the HP BladeSystem infrastructure and plays an important role in helping HP customers build an adaptive enterprise. It provides cost-effective, efficient, hot-plug, redundant power for single server blade enclosure deployments. IT environments can use this solution for blade evaluation purposes, distributed server blade deployments to remote locations, and heterogeneous server blade deployments within a single rack. IT environments with deeply entrenched power distribution environments can leverage the 1U power enclosure to help accommodate existing PDU strategies. The HP BladeSystem p-Class 1U power enclosure also has backwards compatibility, allowing IT administrators at small and mediumsized businesses to leverage their previous IT investments by fitting the 1U power enclosure into existing racks in their infrastructure.

For more information

For additional information, refer to the resources listed below.
Source HP BladeSystem website HP BladeSystem p-Class Enclosure Installation Instructions HP BladeSystem p-Class 1U Power Supply Installation Instructions HP power distribution units website HP rack-mountable uninterrupted power supplies website Hyperlink www.hp.com/go/bladesystem
http://h20000.www2.hp.com/bc/docs/support/SupportManual/ c00383406/c00383406.pdf http://h20000.www2.hp.com/bc/docs/support/SupportManual/ c00383401/c00383401.pdf http://h18004.www1.hp.com/products/servers/proliantstorage/ power-protection/power-distribution/index.html http://h18004.www1.hp.com/products/servers/proliantstorage/ power-protection/rackups/index.html

Call to action

Send comments about this paper to: TechCom@HP.com.
2005 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. TC051203TB, 12/2005