Using DC Power

A P P E N D I X E

Using DC Power

This appendix describes using the DC Power Source option for the Sun StorageTek 2500 Series Arrays in the following sections:

DC Power Overview

Installation Notes for DC Power

DC Power Overview

The Sun StorageTek 2500 Series Arrays can be ordered with a DC power connection and connector cables.

Caution - A qualified service person is required to make the DC power connection per NEC and CEC guidelines. A two-pole 20-amp circuit breaker is required between the DC power source and the trays for over-current and short-circuit protection. Before turning off any power switches on a DC-powered CRU or module, you must disconnect the two-pole 20-amp circuit breaker.

Caution - Electrical grounding hazard - This equipment is designed to permit the connection of the D.C. supply circuit to the earthing conductor at the equipment.

FIGURE E-1 shows the locations of the power-fan assemblies.

FIGURE E-1 Power Fan Assembly Locations

Figure showing the power fan assembly locations.

The power-fan assemblies above are shown with AC power connectors. The DC power connector can be seen in FIGURE E-3. The DC power connector cable and source wires are shown in FIGURE E-2 below.

FIGURE E-2 DC Power Connector Cable and Source Wires

Figure showing the DC power connector cable and source wires.

Caution - Risk of electrical shock - The tray has more than one power source.
To remove all power from the tray, all DC MAINS must be disconnected by removing all power connectors from the power-fan assemblies. See Installation Notes for DC Power for more information.

Installation Notes for DC Power

The sections that follow provide hardware information about DC power.

Ship Kit Changes

DC Power LEDS

Connecting Power Cables

Turning Off the DC Power During an Emergency

Relocation Cautions

Ship Kit Changes

If the DC power option is ordered, two DC power connector cables are provided with each controller tray for connection to centralized DC power plant equipment.

Caution - A qualified service person is required to make the DC power connection per NEC and CEC guidelines. A two-pole 20-amp circuit breaker is required between the DC power source and the tray for over-current and short-circuit protection. Before turning off any power switches on a DC-powered CRU or module, you must disconnect the two-pole 20-amp circuit breaker.

DC Power LEDS

FIGURE E-3 shows the LEDs, on/off power switch, and power cable receptacle on the back of the DC power-fan assembly.

FIGURE E-3 DC Power-Fan Assembly LEDs, Power Switch, and Power Cable Receptacle

Figure showing the DC power-fan assembly LEDs, power switch, and power cable receptacle.

TABLE E-1 lists the LEDs for DC power.

TABLE E-1 DC Power-Fan Assembly LEDs

LED	Color	On	Off
DC Power (DC Good)	Green	DC power from the power-fan assembly is available.	DC power from the power-fan assembly is not available.
Service Action Allowed	Blue	The power-fan assembly can be removed from the tray.	The power-fan assembly cannot be removed from the tray.
Service Action Required (Fault)	Amber	A fault exists within the power-fan assembly.	Normal condition
Power (DC Good)	Green	Power is present	Power is not present

Table showing the DC power-fan assembly LED names, colors, and status descriptions for both “On” and “Off” conditions.

Connecting Power Cables

Caution - A qualified service person is required to make the DC power connection per NEC and CEC guidelines. A two-pole 20-amp circuit breaker is required between the DC power source and the tray for over-current and short-circuit protection. Before turning off any power switches on a DC-powered CRU or module, you must disconnect the two-pole 20-amp circuit breaker.

Caution - Ensure that you do not turn on power to the controller tray or the connected drive expansion trays until this guide instructs you to do so. For the proper procedure for turning on the power, see Connecting Power Cables.”

Caution - Electrical grounding hazard - This equipment is designed to permit the connection of the D.C. supply circuit to the earthing conductor at the equipment.

Connecting the Cables

1. Disconnect the two-pole 20-amp DC circuit breaker for the storage array.

2. Ensure that all DC power switches on the DC-powered controller tray and all DC power switches on any connected, DC-powered drive expansion trays are turned off.

3. Connect the DC power connector cable to the DC power connector on each power-fan assembly on the back of the controller tray.

Caution - The three source wires on the DC power connector cable (-48 VDC) connect the trays to centralized DC power plant equipment, typically through a bus bar located above the cabinet.

4. A qualified service person is required to make the DC power connection per NEC and CEC guidelines. A two-pole 20-amp circuit breaker is required between the DC power source and DC-powered trays for over-current and short-circuit protection. Connect the DC power source wires on the other end of the DC power connector cable to the centralized DC power plant equipment as follows (see DC Power Connector Cable and Source Wires).

a. Connect the brown -48-VDC supply wire to the negative terminal.

b. Connect the blue return wire to the positive terminal.

c. Connect the green/yellow ground wire to the ground terminal.

5. If applicable, connect a DC power cable to each power-fan assembly on each DC-powered drive expansion tray in the storage array.

Turning Off the DC Power During an Emergency

Caution - Potential loss of data - An emergency shutdown of the storage array might not allow the server to complete its I/O to the storage array.

Note - Before turning off the power switches on a DC-powered tray you must disconnect the two-pole 20-amp circuit breaker.

Relocation Cautions

Use the following guidelines when relocating trays or drives from one storage array to another.

Caution - Potential data loss - Moving a storage array or array components that are configured as part of a volume group can result in data loss. To prevent data loss, always consult a Customer Support representative before relocating configured drives, controller trays, or drive expansion trays.

Note - Trays in storage arrays can be connected to the DC power supply (-48 VDC). Before turning off any power switches on a DC-powered tray, you must disconnect the two-pole 20-amp circuit breaker.

Do not move controller trays or drive expansion trays that are part of a volume group configuration. If you must move array components, contact a Customer Support representative for procedures. A Customer Support representative might direct you to complete several tasks prior to undertaking the relocation. These tasks might include:

Creating, saving, and printing an array profile of each storage array that is affected by the relocation of a drive or tray.

Performing a complete backup of all data on the drives that you intend to move.

Verifying that the volume group and each of its associated volumes on the affected storage array have an Optimal status.

Determining the location and status of any global hot spares associated with the affected storage array.